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QUANTIFICATION AND CHARACTERIZATION OF ADHESION
BETWEEN DOUGH AND PACKAGING MATERIAL

presented by

SHU-SHIN CHOU

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Masters degree in Packaging

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QUANTIFICATION AND CHARACTERIZATION OF ADHESION
BETWEEN DOUGH AND PACKAGING MATERIAL

BY

SHU-SHIN CHOU

A THESIS
Submitted to
Michigan State University

in partial fulfillment of the requirements
for the degree

MASTER OF SCIENCE

School at Packaging

1992

ABSTRACT
QUANTIFICATION AND CHARACTERIZATION OF ADHESION
BETWEEN DOUGH AND PACKAGING MATERIAL
BY

SHU-SHIN CHOU

Degree of adhesion between dough and contacting surface was studied.
A wettability test was performed as a indicator of adhesion, and a modified
tensile strength apparatus (Stickiforce Meter) was used to determine adhesion
between dough and film. In the phase I study, adhesion between fourteen
packaging materials and one flour was studied under different temperatures
(23°C and 4°C). To simulate the different potential conditions for film contact
with dough, the following yeast conditions were used: dough-proof, and contact
with film; and dough contact with film, and proof. Wettability and Stickiforce
Meter measurements were highly correlated. Proof-first-yeast dough at 4°C on
PET G film formed the most adhesive bonds, and contact-first-yeast dough at
23°C on Teflon film had the least adhesive bonds. Phase II study used three
different films (PE, PH, and TEFLON) and three flours (Hi-protein, bread, and
pastry). The results indicated that bread flour with no-yeast dough on PE film at
4°C had the highest adhesiveness, and pastry flour with contact-first-yeast
dough on Teflon film at 23°C had the lowest adhesive properties. Film type,

yeast condition, flour type, and temperature all affected dough stickiness.

To my mother, Yi-Ling Chen and my father, Hsing-Ling Chow

ACKNOWLEDGMENTS

I would like to express my sincere gratitude to Dr. Bruce Harte, my advisor, for
his guidance, support, and encouragement. Appreciation and gratitude is

expressed to Dr. Christopher Lai for sharing his time and expertise in methods
development and interpretation of the results. Appreciation is expressed to Dr.

Mary Zabik and Dr. Gary Burgess for their participating on my guidance

committee.

My thanks are extended to Dr. Gill and Dr. Julian Lee for their help in

developing the statistical analyze used in this work.

Special thanks are extended to all my Chinese friends, and my fellow graduate

students for their friendships, and their assistance which helped to make this

study successful.

Finally, I would like to express my deepest thanks to Douglas & Athena Warner,
my brother-in-law and my sister, Famin & Li-Ling Chou, my brother and sister-
in-Iaw for their love and encouragement which helped to make this endeavor

enjoyable. Without them, it would not have been possible.

iv

TABLE OF CONTENTS

LIST OF TABLES .................................. viii
LIST OF FIGURES .................................. xiii
INTRODUCTION ................................... 1
REVIEW OF LITERATURE ................................... 4
Theory of Adhesion ................................... 4
Definitions and classifications ......................... 4
Mechanical Interlocking ........................ 5
Diffusion Theory ............................. 6
Wetting and Surface Tension ......................... 8
Surface Tension and Wettability ................. 15
The Interaction Between Packaging Material and
Product .................................. 18
Chemical and Physical Properties of Dough .................. 20
Type of Flour and Formation of Dough ................. 20
Dough Development ......................... 21
Constituent Components of Dough Associated With
Functional Preperties ........................ 23
Measurement of Physical/ Functional Properties
of Dough ................................. 32
Correlation of Measurement in Stickiness with Food ............. 33
Methods of Measurement in Stickiness ................. 34

MATERIALS AND METHODS ................................. 42

Materials .................................. 42

Flour Samples .................................. 42

Film Samples .................................. 42

Analytical Measurements ................................ 44

Determination of the Initial Flour Moisture Content

(IMC) .................................. 44

Determination of the Protein Content .................. 45
Determination of the Water Absorption Properties -

Farinograph ............................... 45

Stickiforce Meter Determination ...................... 46

Inclined Plane Determination ........................ 46

Experimental Design .................................. 48

Phase I Study ................................... 48

Treatment Variables ......................... 50

Phase II Study .................................. 51

Dough Preparation .......................... 51

Treatment Variables ......................... 53

Statistics Analysis .................................. 54

Phase I Study ................................... 54

Phase II Study .................................. 55

RESULTS AND DISCUSSION ................................. 56

Phase I Study .................................. 56

Inclined Plane Determination ........................ 56

Stickiforce Meter Determination ...................... 56

Wtforce/thass Results ........................... 62

thass .................................. 62

Wtforce .................................. 71

Phase II Study .................................. 80

Inclined Plane Determination ........................ 80

Protein in Flours ................................. 81

Stickiforce Meter Determination ...................... 81

Wtforce/thass Results ........................... 86

thass .................................. 86

Wtforce ................................. 104

CONCLUSIONS ................................. 1 19

RECOMMENDATIONS ................................. 125

APPENDICES

pendix A
Calculations for Absorption at 14%
Moisture Content Basis ................ 126
Appendix B ....
Tukey's Honestly Significant Difference Test of Wtforce
and thass Results for Phase I study ....... 127
pendix c ' ' ' '
Tukey’s Honestly Significant Difference Test of Wtforce
and thass Results for Phase II Study .......... 138
BIBLIOGRAPHY ................................ 154

vii

Table 1.

Table 2.

Table 3.

Table 4.

Table 5.

Table 6.

Table 7.

Table 8.

Table 9.

Table 10.

LIST OF TABLES

Film samples used in Wettability and Stickiforce Meter

- Phase I study .............................

Film samples used in Wettability and Stickiforce Meter

- Phase II study ............................

Wettability of distilled water and 50% ethyl alcohol

on different material surface. (Phase I study) ........

The effect of treatment on the weight-mass gain per
unit (gm /cm2) determined by stickiforce meter (Phase

I study) ..................................

The effect of treatment on the weight-force gain per
unit (gm/cm?) determined by stickiforce meter (Phase

I study) ..................................

Ranking of dough stickiness to coding (Phase I study)

Analysis of variance for Wtforce values of fourteen
different films under different yeast conditions at

various temperature .........................

Analysis of variance for thass values of fourteen
different films under different yeast conditions at

various temperature .........................

Wettability of distilled water and 50% ethyl alcohol

on different material surfaces (Phase II study) .......

The percentage protein in pastry, bread, and Hi-

protein flours ..............................

viii

43

45

57

58

60

61

63

63

81

82

Table 11. The effect of treatment on the Weight-mass gain
per unit (gm/cm?) determined by stickiforce meter
(Phase II study) ............................ 83

Table 12. The effect of treatment on the Weight-force gain
per unit (gm/cmZ) determined by stickiforce meter
(Phase II study ............................. 85

Table 13. Analysis of variance for Wtforce values of three
different types of flours under three different
yeast conditions at various temperature on three
different films .............................. 87

Table 14. Analysis of variance for thass values of three
different types of flours under three different yeast
conditions at various temperature on three

different films .............................. 88
Appendix A
Calculations for Absorption at 14% Moisture Content Basis ...... 126
Appendix B
Table 15. thass mean values of the test materials ........ 127
Table 16. thass mean values of the test materials with proof-
first and contact-first yeast dough .............. 128
Table 17. thass mean values of the test materials at room
(23°C) and refrigerated (4°C) temperature ........ 129

Table 18. thass mean values of proof-first and contact-first
yeast dough at room (23°C) and refrigerated (4°C)
temperature .............................. 130

Table 19. thass mean values of the test materials with proof-
first and contact-first yeast dough at room (23°C)

and refrigerated (4°C) temperature .............. 131
Table 20. Wtforce mean values of the test materials ......... 132
Table 21. Wtforce mean values of the test materials with proof-

first and contact-first yeast dough .............. 133

Table 22.

Table 23.

Table 24.

Appendix C
Table 25.

Table 26.

Table 27.

Table 28.

Table 29.

Table 30.

Table 31.

Table 32.

Table 33.

Wtforce mean values of the test materials at room
(23°C) and refrigerated (4°C) temperature ........ 134

Wtforce mean values of proof-first and contact-first
yeast dough at room (23°C) and refrigerated
(4°C) temperature .......................... 135

Wtforce mean values of the test materials with
proof-first and contact-first yeast dough at
room (23°C) and refrigerated (4°C) temperature . . . . 136

thass mean values of proof-first, contact-first,
and no-yeast dough ........................ 138

thass mean values of Hi-protein, bread, and pastry
flour ................................. 138

thass mean values of proof-first, contact-first,
and no-yeast dough with Hi-protein, bread, and
pastry flour ............................... 139

thass mean values of room (23°C) and refrigerated
(4°C) with proof-first, contact-first, and
no-yeast dough ........................... 139

thass mean values of room (23°C) and refrigerated
(4°C) with Hi-protein, bread, and pastry flour ...... 140

thsss mean values of proof-first, contact-first,

and no-yeast dough with Hi-protein, bread, and

pastry flour at room (23°C) and refrigerated

(4°C) temperature .......................... 140

thsss mean values of PE, PET, and TEFLON film . 141

thass mean values of proof-first, contact-first,
and no-yeast dough on PE, PET, and TEFLON film . . 141

thass mean values of Hi-protein, bread, and pastry
flour on PE, PET, and TEFLON film ............. 142

Table 34.

Table 35.

Table 36.

Table 37.

Table 38.

Table 39.

Table 40.

Table 41.

Table 42.

Table 43.

Table 44.

Table 45.

Table 46.

Wtrnass mean values of Hi-protein, bread, and pastry
flour with proof-first, contact-first, and
no—yeast dough on PE, PET, and TEFLON film .....

thass mean values of room (23°C) and refrigerated
(4°C) temperature with PE, PET, and TEFLON film . .

Wtforce mean values of proof-first, contact-first,
and no-yeast dough ........................

Wtforce mean values of Hi-protein, bread, and pastry
flour

Wtforce mean values of proof-first, contact-first,
and no-yeast dough with Hi-protein, bread, and
pastry flour ...............................

Wtforce mean values of room (23°C) and refrigerated
(4°C) with proof-first, contact-first, and
no-yeast dough ...........................

Wtforce mean values of room (23°C) and refrigerated
(4°C) with Hi-protein, bread, and pastry flour ......

Wtforce mean values of proof-first, contact-first,

and no-yeast dough with Hi-protein, bread, and
pastry flour at room (23°C) and refrigerated

(4°C) temperature ..........................

Wtforce mean values of PE, PET, and TEFLON film . .

Wtforce mean values of proof-first, contact-first,
and no—yeast dough on PE, PET, and TEFLON film . .

Wtforce mean values of Hi-protein, bread, and pastry
flour on PE, PET, and TEFLON film .............

Wtforce mean values of Hi-protein, bread, and pastry
flour with proof-first, contact-first, and
no-yeast dough on PE, PET, and TEFLON film .....

Wtforce mean values of room (23°C) and refrigerated
(4°C) temperature with PE, PET, and TEFLON film . .

xi

142

143

144

145

145

146

146

147

147

148

148

149

Table 47.

Table 48.

Table 49.

Table 50.

Wtrnass mean values of proof-first, contact-first, and
no-yeast dough at room (23°C) and refrigerated (4°C)
with PE, PET, and TEFLON film ................ 150

Wtforce mean values of proof-first, contact-first, and
no-yeast dough at room (23°C) and refrigerated (4°C)
with PE, PET, and TEFLON film ................ 151

thass mean values of Hi-protein, bread, and pastry
flour at room (23°C) and refrigerated (4°C)
with PE, PET, and TEFLON film ................ 152

Wtforce mean values of Hi-protein, bread, and pastry

flour at room (23°C) and refrigerated (4°C)
with PE, PET, and TEFLON film ................ 153

xii

Figure 1.
Figure 2.
Figure 3.
Figure 4.

Figure 5.

Figure 6.

Figure 7.

Figure 8.

Figure 9.

Figure 10.

Figure 1 1.

Figure 12.

LIST OF FIGURES

Adhesion depends on wetting of the surface .....
Stickiforce Meter .........................
Sliding of a drop of fluid along a tilted plane .....
Flow chart of Phase II study ................

The Wtrnass values of proof-first and contact-first
yeast dough on various films ................

Tukey’s HSD test Wtrnass mean values of various
types of material with proof-first and contact-
first yeast ..........................

The thass values of room and refrigerated
temperature dough on various films ...........

Tukey’s HSD test Wtrnass mean values of various
types of material at room temperature and
refrigerated temperature ...................

The Wtrnass values of proof-first and contact-first
yeast dough at room and refrigerated temperature

Tukey's HSD test thass mean values of proof-first
and contact-first yeast at room and refrigerated
temperature ..........................

The thsss values of proof-first and contact-first
yeast dough at room temperature (23°C) .......

The thass values of proof-first and contact-first
yeast dough at refrigerated temperature (4°C) . . .

xiii

......... 9
........ 47
........ 49

........ 52

........ 65

........ 67

........ 67

........ 70

........ 7O

Figure 13.

Figure 14.

Figure 15.

Figure 16.

Figure 17.

Figure 18.

Figure 19.

Figure 20.

Figure 21.

Figure 22.

Figure 23.

Figure 24.

Figure 25.

The Wtforce values of proof-first and contact-first
yeast dough on various films ........................ 73

Tukey’s HSD test Wtforce mean values of various
types of material with proof-first and contact-first yeast ...... 73

The Wtforce values of room and refrigerated
temperature dough on various films ................... 77

Tukey‘s HSD test Wtforce mean values of various
types of material at room and refrigerated temperature ..... 77

The Wtforce values of proof-first and contact-first
yeast dough at room and refrigerated temperature ........ 78

Tukey’s HSD test Wtforce values of proof-first
and contact-first yeast dough at room and
refrigerated temperature ........................... 78

The Wtforce values of proof-first and contact-first
yeast dough at room temperature (23°C) ............... 79

The Wtforce values of proof-first and contact-first
yeast dough at refrigerated temperature (4°C) ........... 79

The thass values of proof-first, contact-first,
and no-yeast dough with Hi-protein, bread, and
pastry flour

Tukey's HSD test thass mean values of proof-first,
contact-first, and no-yeast dough with Hi-protein,
bread and pastry flour ............................. 91

The thass values of proof-first, contact-first, and
no-yeast dough with room and refrigerated
temperature

Tukey’s HSD test thass mean values of proof-first,
contact-first and no-yeast dough at room and
refrigerated temperature ........................... 92

The thass values of Hi-protein, bread, and pastry
flour dough at room and refrigerated temperature ......... 94

xiv

Figure 26.

Figure 27.

Figure 28.

Figure 29.

Figure 30.

Figure 31.

Figure 32.

Figure 33.

Figure 34.

Figure 35.

Figure 36.

Figure 37.

Tukey’s HSD test Wtrnass mean values of Hi-protein,
bread, and pastry flour at room and refrigerated
temperature

The Wtrnass values of Hi-protein, bread, and pastry
flour with proof-first, contact-first and no-yeast

dough at room (23°C) temperature ...............

The thass values of Hi-protein, bread, and pastry
flour with proof-first, contact-first and no-yeast

dough at refrigerated (4°C) temperature ............

The thass values of proof-first, contact-first, and

no—yeast dough on PE, PET, and TEFLON film .......

Tukey’s HSD test thass mean values of proof-first,
contact-first, and no—yeast dough on PE, PET, and
TEFLON film

The thass values of Hi-protein, bread, and pastry

flour on PE, PET, and TEFLON film ...............

Tukey’s HSD test thass mean values of Hi-protein,
bread, and pastry flour on PE, PET, and TEFLON

film ...............................

The thass value of Hi-protein, bread, and pastry
flour on PE, PET, and TEFLON film with proof-first-

yeast dough

The thass value of Hi-protein, bread, and pastry
flour on PE, PET, and TEFLON film with contact-

first-yeast dough ..............................

The thass value of Hi-protein, bread, and pastry

flour on PE, PET, and TEFLON film with no-yeast dough . . .

The thass values of room and refrigerated temperature

dough on PE, PET, and TEFLON film ................

Tukey’s HSD test thass mean values of room and
refrigerated temperature dough with PE, PET, and
TEFLON film

95

95

97

100

101

103

Figure 38.

Figure 39.

Figure 40.

Figure 41.

Figure 42.

Figure 43.

Figure 44.

Figure 45.

Figure 46.

Figure 47.

Figure 48.

Figure 49.

Figure 50.

The Wtforce values of Hi-protein, bread, and pastry

flour with proof-first, contact-first, and no-yeast dough ..... 105
Tukey’s HSD test Wtforce mean values of Hi-protein,

bread and pastry flour with proof-first, contact-

first, and no—yeast dough .......................... 105
The Wtforce values of proof-first, contact-first,

and no-yeast dough at room and refrigerated temperature . . 108
Tukey’s HSD test Wtforce mean values of proof-first,
contact-first and no-yeast dough at room and

refrigerated temperature .......................... 108
The Wtforce values of Hi-protein, bread, and pastry

flour dough at room and refrigerated temperature ........ 109
Tukey’s HSD test Wtforce mean values of Hi-protein, bread,
and pastry flour at room and refrigerated temperature ..... 109
The Wtforce values of Hi-protein, bread, and pastry

flour with proof-first, contact-first and no-yeast

dough at room (23°C) temperature .................. 111
The Wtforce values of Hi-protein, bread, and pastry

flour with proof-first, contact-first and no-yeast

dough at refrigerated (4°C) temperature ............... 111
The Wtforce values of proof-first, contact—first, and

no-yeast dough on PE, PET, and TEFLON film .......... 112
Tukey’s HSD test Wtforce mean values of proof-first,

contact-first, and no-yeast dough on PE, PET, and

TEFLON film .................................
The Wtforce values of Hi-protein, bread, and pastry

flour on PE, PET, and TEFLON film .................. 114
Tukey’s HSD test Wtforce mean values of Hi-protein,

bread, and pastry flour on PE, PET, and TEFLON film ..... 114
The Wtforce value of Hi-protein, bread, and pastry

flour on PE, PET, and TEFLON film with proof-first-

yeast dough

Figure 51.

Figure 52.

Figure 53.

Figure 54.

The Wtforce value of Hi-protein, bread, and pastry flour
on PE, PET, and TEFLON film with contact-first-yeast dough 115

The Wtforce value of Hi-protein, bread, and pastry flour
on PE, PET, and TEFLON film with no-yeast dough ....... 116

The Wtforce values of room and refrigerated temperature
dough on PE, PET, and TEFLON film ................. 118

Tukey’s HSD test Wtforce mean values of room and
refrigerated temperature dough on PE, PET, and
TEFLON film ................................. 118

xvii

CHAPTER 1

INTRODUCTION

Adhesiveness or stickiness between the food stuff and
the packaging surface is a complex phenomenon. The sticking
of food to packaging surface can be desirable or undesirable
to both the processor and the consumer. For example, the
keeping quality of sausage products is known to be closely
related to the degree of adhesion of meats to the casing.
0n the other hand, the adhering of a food product to the
contact surface can result in product loss, and in some
cases, poor product appearance. Examples are the adhering
of sauces to the surface of squeezable bottles and the
attaching of pizza cheese to the surface of folding cartons.

Lai (1985, 1987) reviewed the adhesion theories and the
factors that affect stickiness. The word adhesion is
broadly used to describe the sticking together of two
materials with or without an intermediate layer. It is an
interfacial phenomenon which, in the food-packaging system,
generally involves the liquid-solid interface or solid-solid
interface.

Only a few methods have been used to measure food

stickiness. Most procedures use tensile testing

2
instruments. The negative curve obtained during the
measurement has been interpreted to be proportional to the
work needed to overcome the stickiness. Other stickiness
testing devices which use a similar principle are the
Struct-O-Graph (Gaines, 1982), Tensile Adhesion Tester
(Yokoyama, 1966), and Adhesion Test Balance (Kumar, et al.,
1975). Another common procedure employed to measure
stickiness involves weighing the material adhered to the
contacted surface (Motegi, 1979; Yokoyama, 1966; Taguchi, et
al., 1979). The degree of stickiness is correlated to the
weight of the product adhered.

Though much attention has been given to many of the
chemical and physical properties of food products and
polymers including adhesion, little is known about the role
of the interface in food product-packaging material
interaction, in particular adhesion between a foodstuff and
packaging material. Lai (1988) demonstrated that different
semi-solid foods interacted differently with plastic
surfaces. Furthermore, surface properties of plastics are
known to vary due to differences in polymer melt,
modification by additives, or chemical reactions (Frisch, et
al., 1976; Hair, 1967).

As the food industry continues to move toward
convenience and pre-cooked foods, increasing numbers of food
products are processed at centralized locations in large

volumes. Gene Hoffman (Williams, 1990), the senior vice

3

president of SuperValu stores, observed that pre-cooked
foods have been identified as a major channel through which
retailers and wholesalers can get into serious food
marketing. Refrigerated foods offer the consumer the
greatest potential for convenience and quality. Many of
these products are microbiologically sensitive and have
short shelf life. Refrigerated dough is one such product
(Pomeranz, 1964). It is often presheeted and cut into
shape, requiring minimum preparation by the customer. To
avoid spoilage of dough, the product must be kept below
40°F. Quality control of ingredients and processing
conditions must be rigorously maintained during production
to minimize mold, yeast, and bacteria in growth in the
dough. Careful consideration must also be given to
packaging of the final product. Sticking of dough to the
surface of its container can result in the loss of dough,
poor product appearance, and customer dissatisfaction.

The objectives of this study are:

1. To evaluate a device for determining adhesion
between refrigerated dough and the contacting surface.

2. To determine the influence of flour type, yeast
condition, and temperature on adhesion between dough nd

plastic films.

CHAPTER 2
LITERATURE REV I E.
2.1. Theory of Adhesion

2.1.1 Definitions and classifications

Adhesion is the phenomenon that results in surfaces
being held together by interfacial forces (Bikales, 1971).
The force may be mechanical, electrostatic, or due to
molecular attraction. Which type of force depends on
whether the interfacial forces results from interlocking
action, from the attraction of electrical charges, or from
valence forces. Adhesion (ASTM D 907-55, 1958), is defined
as the attraction between surfaces being held together by
valence forces of the same type as those that cause
cohesion, while a substance capable of holding materials
together by surface attachment could be defined as an
adhesive.

Eley (1961) stated that in physical chemistry,
attraction between a solid surface and a second phase is
called adhesion. Electrostatic forces, van der Waals
forces, or chemical valence forces may all promote adhesion.
The technical process of producing adhesion between two
solids is called adhesive bonding. In many situations, this

process is irreversible.

5

A brittle adhesive will fracture cohesively on impact
loading because the fracture stress is surpassed (Houwink et
a1, 1965). A rapidly loaded rubbery adhesive behaves much
like a tough plastic. The adherend will tend to break or
deform. But, by using an interlayer of metal oxides to form
a boundary, the same rubber will break cohesively.

In order to form an adhesive joint, the adhesive must
move into the bond area and remain there until the bond is
complete (Dr. Alfrey, 1948). Therefore, the rheology of
polymer systems has a significant role in adhesion. The
measurement and understanding of intermolecular forces
responsible for adhesion and cohesion is quite important for
chemists and engineers whose work involves adhesion.

C CK NC

A mechanical interlocking of an adhesive with the
surface structure of the adherend on a scale which could be
easily recognized and discerned is the oldest and most
simple theory concerning adhesion (Booth 1990). However, as
adhesive technologies began to incorporate more rigid
materials with smooth surface, the overall concept of
mechanical bonding became inadequate. In recent times the
following four broad areas have been used to explain the
normal adhesive phenomena: diffusion process, electrostatic
interactions, mechanical interlocking, and adsorption or
specific interactions. A fifth category, viscous flow and

pressure-sensitive adhesive is used in the particular case

6
of pressure-sensitive adhesives.
DIEEHSIQH_IEEQBX

Voyutskii (1963) initiated work on the diffusion theory
of adhesion. Voyutskii's looked at the adhesion of layers
of rubbery materials to each other. This lead to
'autohesion', or the process of self adhesion. Autohesion
occurs when the macromolecules are mobile. Portions of the
long chain molecules interdiffuse if the two polymer
surfaces are in close contact at a temperature above the
Glass Transition Temperature (Tg).

Vasenin's (1965) concept of adhesion was developed in a
more quantitative form. He provided formula expressions,
although the mathematics were complex, for the force
required to separate two polymer surfaces. This force was
directly proportional to the rate of separation and to the
fourth root of the time that the surfaces were in contact,
as well as inversely proportional to the two-thirds root of
the molecular weight to express the force of peeling
separation.

Campion (1975) considered the roll free volume played
within the structure of polymers. He correlated autohesion
properties with the cross-sectional area of these holes in
the structure. A certain amount of free space exists close
to the polymer chain because of the geometry of the
molecules. As Young (1805) and others have shown, diffusion

is a reasonable and useful explanation of adhesion. When

7
the two polymer surfaces are above their Glass Transition
Temperature, their molecular chains have same mobility.

Derjaguin (1955) and co-workers developed an
explanation for some of the properties of pressure-sensitive
tape based upon the concept of an electrostatic double layer
at the interface. The peeling apart of the adhered surfaces
was identified as an electrical capacitance, with the
electrical energy stored within. Derjaguin (1969)
emphasized that the force of attraction between the plates
of a condenser is independent of their distance from each
other. Once the process of separation has commenced and the
separation of the two parts of a joint increased, the
electrostatic force will become much more significant.

Mechanical interlocking in structural joints has had a
great impotance in the aerospace industry and in the
production of motor vehicles. It is phenominal that
abrading a surface frequently results in stronger bonds.
Abrasion takes away a whole range of materials such as dirt
and dust, grease or films of oil, poorly adhering layers of
oxide etc., so that a relatively clean surface can be
obtained and enables a stronger bond to be occur.

Valency forces are usually described as the mechanical
strength of any solid material which originates from the
various forces of attraction between the ultimate particles
(Booth, 1990). Van der Waals' forces are always present no

matter which of these forces are significant in any

8
particular material, and their numbers depends upon the
chemistry involved.

2.1.2 letting and surface tension

Basic to Young's (1805) concept of adhesion is the
contact angle 9 between a drop of liquid and a solid surface
(Fig 1). The liquid is static when 6 > 0°. At a rate
depending on the viscosity and surface roughness, the liquid
will wet the solid completely, and then spread freely over
the surface. Therefore, contact angle, 6, not only is a
good inverse measure of wetting and spreadability, but of
adhesion as well.

Young (1805) initiated the theory that three surface
tensions, stor ySL°, and yLv°, existing at the phase
boundaries of a drop of liquid at rest on a solid surface
(Fig 1), form a system in static equilibrium. If the
molecules that make up the surface are more polar, the
surface is easier to wet and bond with a polar liquid
adhesive. Consider two glass plates between water for
example. The polar groups in the glass plate's surface
attract the water molecules and the liquid spreads over the
surface. The force of adhesion becomes evident when you try
to pull the glass plates apart. Therefore, the essentials
for good bond formation would be a liquid adhesive which
gives close molecular contact, wets the surfaces to be
adhered, and solidifies the liquid between the surfaces.

The energy involved in the relationship between a

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10
liquid and a solid in contact has to be taken into
consideration. Young (1805) considered that a drop of
liquid on a solid surface is in equilibrium which resulted
in the following equation:

vsv = 731, + rm (case) (1)

Dupre (1869) also expressed the reversible
thermodynamic work of adhesion to separate two phases which
were originally in contact with each other using the
following equation:

WA= yl + 72 - 712 (2)
where y = surface tension

0 = contact angle conventionally measured through the

liquid

WA= the work of adhesion
In Young's equation, the solid and the liquid were in
equilibrium with the vapor, but in Dupre's equation both
surfaces were clean and the solid was not in equilibrium
with vapor. There is an additional term needed, which is
the spreading pressure to express the difference in energy
between a clean solid surface in a vacuum and the samesolid
surface in equilibrium with the vapor of a liquid. The
equation is:

WA = VLv (1 + cosO) + n (3)

The contact angle indicates the extent a liquid wets and
spreads spontaneously on a solid. The liquid will remain a

droplet if the temperature is close to 180°F (see figure 1);

11
but will wet and spread on the solid surface if 6 is small.
This proves that the smaller the contact angle the better
the solid will wet. External pressure can also be applied
to the solid to increase the wetting and spreading.

The spreading of a liquid over a solid, occurs through
the condensation of vapor from the liquid over the solid
and the subsequent spreading of the bulk of the liquid over

the film of condensed vapor (Burden, 1949). Spreading is
the process that involves a reduction in free energy. A
solid surface is easily contaminated with foreign matter in
a thin layer unless special precautions are taken. When
left unprotected in ordinary air even for a short while, a
film of greasy material will be detected on a solid surface.
Quincke (1859) found that when the surfaces are considerably
torn and scratched, sliding becomes impossible unless great
force is applied. The ease of wetting is greatly decreased
by traces of grease which in turn increase the contact angle
against water.

Dupre's equation for a solid and a liquid:

wsL = st + YLA + YSL (4)

where ysA = surface tension of the solid against air

surface tension of the solid against liquid

78L

surface tension of the liquid

YLA
Equation (4) shows the relative strengths of the

adhesion of the liquid to the solid, and from it can be

determined the contact angle. When the liquid attracts the

12
solid as much as it attracts itself or when the liquid
attracts the solid more than it attracts itself, the contact
angle will be zero, W = ZyLA. When the attraction of the
liquid for the solid is half that of itself, the contact
angle will be 90°, and when there is no adhesion between the
liquid and the solid, the contact angle will be 180°.

If two microscopic glass slides are laid on top of each
other with a few drops of water in between, it will be very
difficult to separate them (Booth 1990). Two kinds of
energy must exist in order to separate them. First, the
entire thin, liquid layer between the slides must flow into
a smaller area to allow for the increased distance which
separates them. In order to overcome the viscosity of
liquid flowing through a small gap, an expenditure of energy
is required. This increases the thickness which in turn
increases the surface area around the periphery. Because of
the surface free energy of the additional new surface,
additional energy will be required. Such a phenomenon
exPlains the adhesion of pressure-sensitive tape. The
backing is thin and flexible, allowing it to conform closely
when it is applied to a surface and pressed down. By
coating the backing with a thin film of a viscous liquid,
adhesion can occur because the viscous liquid flows across
and penetrates the irregular surface when pressure is
applied. The ability of the backing to conform and the

liQUid to penetrate is dependent upon the pressure applied

13
while applying the tape.

In order to obtain proper wetting between two
substances, A and B, at least one has to be applied in the
liquid or plastic state, or in the highly elastic state
(DeBruyne et al, 1951). When volume and temperature are
constant, the following equation is true (Houwink, 1965):

AF = AU - TAS (5)

Where AF = free energy

U internal energy

S = entropy
AF controls the change in internal energy and the change in
entropy. In order for wetting to occur, the solvent must be
in contact with the molecules of the solid.

According to equation (5), as the solid's molecules
attract those of the solvent, heat is liberated, if AU is
negative, wetting will occur with certainty. When the
solvent attracts its own molecules more than the solid's
molecules attract those of the solvent, then wetting may or
may not occur, depending on the magnitude of (AU - TAS).

Equation (6) shows that wetting results when the
surface of the solid disappears and the interface appears:

Auw = AUS + AUL - AU’SL (6)

energy of wetting

where Uw
US = energy of solid surface
UL = energy of liquid surface

U51." energy of interface

14

Initially, because of van der Waals forces between the
atoms in the two surfaces, the materials adhere to each
other. The real strength of the adhering materials is much
weaker than the interfacial strengths. The absence of weak
boundary layers also brings the two surfaces together.

Conventional techniques, such as surface oxidation by
corona discharge or flame treatment, are believed to be
effective since they create wettable polar surfaces so that
the adhesive may spread spontaneously and provide extensive
interfacial contact (Bikerman, 1968).

The subject of wetting has been dealt with extensively
in the literature (Zisman, 1962, 1963, 1964; Good, 1960,
1964). Several studies have been done, but the mechanisms
and criteria proposed for establishing relationships between
wetting and adhesion have not been consistent. Zisman
(1962, 1963, 1964) recognized many of the pertinent
relationships which occur with adhesion and discussed them
in detail. He did not however establish the importance of
these relationships to the problem of adhesion. Sharp, and
Schonhorn (1964) emphasised the role spreading has on
adhesion and concluded that in order to form a satisfactory
adhesive bond, the adhesive must exhibit a surface tension
at bonding temperature.

Johnson and Dettre (1964) have shown that for most
practical coating or adhesive systems, the adhesive will

exhibit contact angles with the solid subtrate which are

15

less than 90°, case will be positive, and thermodynamic
equilibuium will correspond to a wetted state. Several
factors may affect the rate of wetting, the main factor,
likely being the viscosity of the liquid adhesive. Another
is interfacial topography, which influences the resistance
to flow. Yet another, relates the dimensions of the
interstices directly to the flow rates in the interfacial
interstices.
8 AC N ON W T LITY

Surface tension is the measure of the tendency of the
boundaries between liquids and gases or between two
different liquids to contract (Bikerman 1968). A liquid-
liquid interface is often referred to as interfacial
tension. For this research, wettability of solid polymers
is a far more important property than surface tension of
liquid polymers or of polymer solutions. Whether a polymer
is suitable for a raincoat, can be printed upon, or has easy
gluability depends on its wettability. Contact angle is a
quantitative measure of wettability. The following are
methods used to measure the contact angle: direct
measurement on a drop (Ray et a1, 1985), the drop dimensions
(Allan, 1959), angle of sliding (Bikerman, 1950), (Kawasaki,
1960, 1970), and wetting hysteresis (Bikerman, 1958).
Different methods are employed, depending on the different
kinds of materials and solutions.

Fowkes (1952) stated that the basic factor in wetting

16
is the free energy of interaction between the liquid and
solid phases across the interface. This free energy is
equal to the reversible work of adhesion WA, which is the
sum of several kinds of interfacial attractions:
WA = WAD + Wm + WBP + w," + WEE (7)

where D = dispersion forces

H = hydrogen bonds

P = other polar interactions

n = pi-bonds

E = electrostatic interactions

The work of adhesion can be quantified as W; = YLv +
(st - ySL). This is a useful equation for some supercooled
isotropic liquids when their surface free energies are equal
to the surface tensions.

Interfacial tension is the force which keeps surfaces
apart or causes them to coalesce (Young, 1945). However,
when contact occurs between a solid or a liquid and a gas,
the forces established at the interface are called the
surface tension. A substance may react differently in
different situations. For example, the effect of water
coming in contact with a clean leaf acts differently than
when it makes contact with a dusty leaf; cotton sinks in
soapy water, etc. These differences are a result of surface
active agents. Surface-active agents are compounds which
cause variations in either interfacial tension or surface

tension.

17

The atomic theory states that all matter consists of
atoms and, as a result of recurring constant arrangements of
atoms, many familiar molecules are formed. These molecules
will have average forces in all directions that are equal
and the attraction forces in the interior surface of a mass
of the material will be balanced in all directions, and
there will be uneven forces at the surface. As the
temperature of a liquid increases, the attraction between
the molecules decreases. If the temperature increases to
the critical point, the surface tension becomes zero.

Foreign matter also impacts the adhesive ability of matter.
Two drops of clean mercury fuse very readily, but the
presence of dust, oil, or other foreign matter on the
surface of the mercury will prevent easy union of the two
drops.

A fundamental factor in wetting is the reduction of
surface tension. Given two pure liquids with equal
viscosity and volatility, the one with the lower surface
tension will spread on a clean glass plate more rapidly.
The outer layer of molecules is under contractile tension
because of the unbalanced cohesive forces occurring at the
surface of a liquid. Accordingly, substances such as fatty
acids and alcohols containing both hydrophilic and
hydrophobic groups spread out over a large area. Water wets
a substance only if the forces of adhesion for the adsorbing

surface are stronger than the forces of cohesion between the

18
water molecules.

Langmuir (1916), and Harkins et al (1917) stated that
absorption takes place because of a surface force presence.
Cohesion is the force which holds like molecules together,
and the forces of attraction between unlike molecules is
adhesion. Langmuir and Harkins also stated that in general,
wetting is a chemical phenomena, and the forces related to
it are those classed under adsorption. The terms "chemical
attraction”, "residual valencies", and "unsatisfied chemical
affinities" are also used in connection with adsorption.

Bartell (1931) explained that a most common type of
adsorption of liquid by solid is wetting by water. Wetting
by water may consist of the following three types: (1)
spreading wetting (water wets a plain surface); (2)
adhesional wetting (water acts as a cementing substance
between two or more solids); and (3) immersional wetting
(interior capillaries of a porous substance like wheat
grains are wetted by water). An example of adhesional
wetting by water would be when water assembles the flour
particles into the dough mass.

2.1.3 The interaction between packaging material]
product

Experimental values for adhesive performance are
influenced by the gross-sample geometry, the topography of
the interface, the chemical nature of the materials, the
mechanical responses of the solid and the viscoelastic

phases, strains rates, strain geometry, temperature, and

19
such unknowns as the thermodynamic state of the system
(Huntsberger 1963). Huntsberger developed the concept that
poor performance results from poor interfacial contact. He
also established that the way in which the adhesive bonds
was formed was greatly influenced by the temperature

dependance of the adhesive performance.

The effect of different container surfaces on the flow
rate of food or beverage is an important attribute in fluid
and semi-solid food (Kiosseoglou et a1, 1983). They
suggested that the degree of wetting of the surface is an
important factor affecting spreadability.

Steele (1979) found that bakery products tend to stick
to trays. It was caused by the water in dough wetting the
metal surface and then drying during baking and the
dissolved materials are deposited to form a bond between the
metal and the product. He concluded that in order to
minimize adhesion of dough to aluminum trays, there should
be a high degree of wetting of the aluminum surface with an
oil and a low degree of wetting of the oil surface on the
tray by the water in the dough.

Lebedev et a1 (1975) stated that the surface roughness
of the container influences adhesion. He and a co-worker
found that adhesion of spaghetti dough to molds was related
to the degree of unevenness of the metal surface.

Lai (1985) found that different food materials wetted

the polymeric film differently. He demonstrated that food

20
interacts differently on plastic surfaces by studying their
spreading properties. He also stated that degree of wetting

was determined by the spread ratio, coefficient of wetting,

and coefficient of traction.

2.2. Chemical and Physical Properties of Dough

2.2.1 Type of flour and formation of dough

Wheat flour is a complex system of protein and
carbohydrates and is susceptible to various stress
conditions (Hlynka, 1964). Wheat is unique among the cereal
grains in the type of products which can be produced from it
(Hoseney et al, 1978). Wheat flour is the only flour that
will produce good quality bread, cakes, cookies or pasta.
Although there are many different kinds of wheat grown
around the world, they can be categorized into three types
generally:

(A) The Bread Wheats: These are generally hard wheats
and have a somewhat high protein content.

(B) The Soft Wheats: The bonding between the protein
and starch is weak in this type wheat. This category
produces flour with small particle size and has a low level
of starch damage during milling.

(C) The Pasta Wheats: These are usually hardy wheats
such as durum wheats and are preferred for making pasta.

One of the most important characteristics of a bread
flour is the breadmaking quality (Hoseney et a1, 1978). This

quality can be defined in terms of the number of loaves

21
produced by the flour. Loaf volume is one important
parameter in judging flour. Although a high loaf volume
does not necessarily indicate good flour quality, a poor
loaf volume will indicate poor flour quality. The highest
loaf volume possible consistent with a good crumb grain is
most desirable.
UGH ELOPMENT

A rubbery mass of wet lumps with little coherence, is
obtained during the early mixing of dough ingredients
(Pomeranez, 1964). Gradually, the coherence increases, and
the dough develops elastic properties and begins to pull
away from the mixing bowl which makes the dough more smooth
and gives it a drier appearance. This is called dough
development. The time needed for optimum development
usually varies with the type and speed of the mixer, the
type of flour, and the water content of the dough. However,
as mixing continues, the dough eventually loss its
elasticity, becomes highly extensible and sticky, and in
somewhat fluid. This is usually referred to as dough
breakdown.

Dough could be described as a compound colloid
(Swanson, 1943). When we mix flour with water, the protein
particles which form gluten unite into filaments or strands,
and form a three dimensional network and thus a continuous
phase or system. Starch granules are speshed in this

network. Water absorbed by the protein particles and starch

22
granules also forms into a continuous phase. Ingredients
such as salt, sugar, yeast, and other soluble materials are
dissolved in the water solution and their contact with the
starch and protein is in the discontinuous phase.

Hlynka (1970) suggested that mixing results in
unfolding and orientation of long-chain molecules. This
leads to a condition of more laminar flow in the dough,
which makes the dough less resistant to extension. Hoseney
and Finney (1974) speculated that this orientation of
protein molecules could increase the probability of hydrogen
bonding resulting in a release of water. The increase in
free water in dough may be among the factors explaining the
lower resistance in overmixed dough to extension as well as
its wet and sticky appearance.

Dough mixing involves the combining and blending of the
formula ingredients. After applying sufficient physical
work to the mixture, it will be transformed into a cohesive
mass with the requisite viscoelastic properties (Pyler,
1988). The actual proof time will vary depending on the
dough's character. Factors such as inadequate yeast content
and poor control of time or temperature during fermentation
result in extended proof time.

During fermentation, proofing and baking, the walls of
the dough gas cells are subjected to considerable tensile
and shear stress (Pyler, 1988). Therefore, it is necessary

for them to possess viscoelastic properties which will allow

23
sufficient expansion and also to sustain these extensions
without rupture.

From observation on fermenting doughs (Matz, 1960), it
was formed that there was a tendency for the starch and
gluten to separate during fermentation and for the gluten to
form into transparent cells. These transparent cells were
drawn to the surface because the gas nucleus from which the
bubbles originated is a glutinous core. As the bubbles
expand, the required amount of gluten needed to satisfy
surface needs is drawn from the starch-gluten matrix of the
endosperm material. The properties that enable this to
occur may be controlled by the viscosity and fluidity of the
gluten and the amount of adhesion of the gluten to starch.

Yeast action in fermentation leads to two primary
results: (1) The formation and migration of carbon dioxide
culminating in a network of cellular compartments to lighten
or raise the dough, thereby greatly improving its ultimate
palatability; and (2) the simultaneous production and
concentration of alcohols, aldehydes, ketones, and acids
which contribute to bread aroma and flavor. Yeast also
alters the physical properties of dough, especially the
gluten elasticity, through the powerful stretChing actions
generated by the diffusion and accumulation of carbon

dioxide throughout the dough mass.

24

2.2.2 constituent components of dough associated with
functional properties

According to Parker and Taylor (1966), adhesion can be
defined as the use of one material to bond two other
materials together, and cohesion as the joining together of
the same material (Cherry, 1981). Cooking builds up
additional adhesive and cohesive interactions among protein,
lipid, and carbohydrate components of foods.

Using the scanning electron microscope, Khoo et al
(1975) observed that dough consists of starch granules held
together by a matrix of hydrated gluten protein. Polar
groups contribute greatly to adhesion and cohesion of
protein to carbohydrates. The chemistry of adhesion
involves nonpolar interactions involving long chain
aliphatic or aromatic groups such as Van der Waal or London
fores (Parker et al 1966). Disulfide bonds in the amino
acid cystine are important to the properties of many
proteins by maintaining covalent intramolecular bonds and
crosslinks between protein chains (Wall 1971). Complex
gluten proteins can be separated, by measuring differences
in solubility, which leads to separation into many soluble
proteins and an insoluble protein residue. The effect of
molecular size and shape on protein cohesive strength was
demonstrated by measurements of tensile strength and
elongation of films cast from laboratory preparations of
wheat gluten, gliadin, and glutenin (Wall et a1 1969).

Glutenin consisting of larger, more asymmetric

25
molecules forms films with greater tensile strength than
gliadin films. Gliadin films stretch further than those
from glutenin because of weaker molecular associations.
Gluten, a mixture of gliadin and glutenin, has intermediate
film properties. Reduction of the disulfides of gliadin
increases its viscosity significantly due to unfolding of
the polypeptide molecule. Reduction of glutenin destroys
its cohesive nature when hydrated, but the reduced proteins
are very sticky and quite adhesive.

Because of the existing gluten proteins, hydrated flour
can be worked into an elastic-cohesive mass by mixing.
During mixing, the asymmetric glutenin molecules orient and
associate, thus increasing dough strength.

Orth et al (1972) investigated the relationship between
flours, the variation in dough strength, and their different
protein fractions. They discovered that the mixing time
requirement of dough and the tolerance to mixing correlates
to the residue protein content. Stronger flours not only
contain more residue protein but also more of the higher
molecular weight glutenin fraction.

Glutenin molecules, (large asymmetric shape) have
considerable surface area with numerous exposed functional
groups to permit strong association by noncovalent forces.
Fragments of highly crosslinked residue proteins contribute

lateral cohesion and resistance to laminar flow (Hoseney et

a1 1969). Gluten's cohesive-elastic character holds

26
ingredients and provides a chewy texture which is the basis
for many vegetarian-simulated meat products.

Most globular or albumin plant proteins exhibit little
cohesive or adhesive properties in their native state. At a
pH of 9 or above, however, disulfide bonds cleave, protein
unfolding occurs, and functional groups previously
associated within the molecule become available for external
binding.

Adhesion and cohesion are properties of many polymeric
substances including proteins. Protein's high molecular
weight and random coil structure result in more associations
and the refore enhance adhesive and cohesive properties.

The functional properties of proteins in foods are
determined by the molecular composition and structure of the
individual proteins and their interactions with one another
and with other substances (Wall, 1979). Altering the
constituent proteins or adding other proteins could improve
or modify food characteristics such as viscosity, texture,
water absorption, or fat emulsification.

Proteins of wheat flour govern the plastic and elastic
properties of bread doughs and some types of batters to a
large extent (Pomerane, 1964). The relationship is most
prominent in bread doughs, but the influence of flour
proteins on the physical properties of the doughs and of
batters is much less prominent and less understood. Protein

consists of alpha-amino acids linked by peptide bonds

27
between the carboxyl group of one amino acid and the alpha-
amino group of a second amino acid. This peptide backbone
structure constitutes the primary structure of proteins.

Dough derives its properties from the constituent
components (Pomerane, 1964). The major and most important
group of constituents is the proteins. The wedge and
adhering proteins in the intact grain, or the derived
fractions such as gluten, globulins, albumins, and
lipoproteins are included in this group. The carbohydrates
are the most abundant group, including starches, sugars, and
soluble and insoluble polysaccharides. The lipids form a
small but significant part of the flour. Water plays a key
role in dough formation. Air forms the nuclei of the gas
cells, and the oxygen acts as an improver.

The amount of protein determines the density while the
quality of protein determines the behavior of the three
dimensional gluten network which permeates the dough
(Swanson, 1943). Using higher protein flours, with the same
quality but higher protein content, will result in larger
loaf volumes. If flour has a high percentage of protein,
the gluten mesh-work will be denser.

Osborne (1907) separated the wheat protein into four
distinct proteins: leucosin, water soluble; globulin, salt
soluble; gliadin, alcohol soluble; and glutenin, insoluble.
Based on a protein's structure, composition, solubilities,

and other characteristics, it is classified as a simple

28
protein, conjugated protein, or derived protein.

The most prominent component, gluten, is composed of
two proteins, gliadin and glutenin. These two proteins
effect baking quality. Upson et al (1916) studied the
swelling of wheat gluten. Wheat proteins swell in water and
especially in solutions of dilute acids because of the
entrance of water between the protein molecules and the
molecular structure. During the swelling process, gluten
becomes softer, more flexible, and due to diminished
cohesion, increases in weight and volume.

Phosphate protein interactions could be responsible for
lowering hydrogen bonding activity and subsequent reduction
in water binding, extensibility, and cohesion (DeMan et a1,
1976). The increase in free water may be among the
factors explaining lower resistance to extension of
overmixed dough as well as its wet and sticky appearance.
The viscoelastic properties of wheat dough are primarily
attributed to gluten proteins. These proteins form a
network of linear macromolecules bound together by various
cross-links during the process of dough development.

Because of the high concentration of glutamine in gluten-
forming proteins (about 30%), a great number of hydrogen
bonds form, rendering this protein fraction insoluble.

Using microscopic examination, three phases, starch,
protein, and gas cells, can be distinguished in an

unleavened dough, and yeast cells constitute a fourth phase

29
in a leavened dough (DeMan et a1, 1976). All starch kernels
retain their identity in dough and are embedded in a
continuous matrix of protein. A fine, vesicular structure
with expanding gas cells is developed and maintained during
fermentation and proofing until heat fixes the texture in
bread by protein denaturation and starch gelatinization in
the oven.

The tendency of dough, and particularly gluten, is to
spread into films having great stability and with time-
dependent surface viscoelastic properties, while still being
highly compressible. Glutenin forms a very tough, rubbery
mass when fully hydrated, while gliadin produces a viscous,
fluid mass upon hydration (Pyler et a1, 1973).

Glutenin is a prime contributor to the functional
properties of gluten and dough (Bietz et al, 1973). Wheat
dough's characteristics of viscoelasticity and loaf volume
are primarily due to the gluten protein consisting of
glutenin, gliadin, and small amounts of albumins and
globulins. Hydrated glutenin is tough and cohesive, but
less elastic than the whole gluten, while hydrated gliadin
yields only a viscous mass. Accordingly, the unique
structure and composition of gluten produces the rubberlike
properties of dough. Glutenin constitutes approximately 30
to 40 per cent of the protein in wheat flour, and about half
that in gluten.

Because of cystine residues, disulfide linkages can

30
occur either within (intra-) or between (inter-) protein
chains (Bietz et al, 1973). These linkages determine the
functional properties of native molecules. On the other
hand, if all disulfides were of the inter-chain variety, the
resulting highly branched polymer would not allow suitable
alignment of proteins to form a dough. To form a dough an
optimum balance of inter- and intra- chain disulfide bonds
is essential for good glutenin performance.

Glutenin occurs only in the endosperm, and probably
serves both as structural protein and as reserve material
for the seed. Too much glutenin may prevent expansion of
gas cells during fermentation (Mecham, 1973). An
appropriate combination of glutenin and gliadin is essential
for good dough performance and loaf volume. Glutenin
molecules, because of their high molecular weight, shape,
and their amino acid composition, impart toughness and
strength to gluten. These molecules are favorable for
hydrogen and hydrophobic bonding and provide relatively
large surface areas which are suitable for molecular
association. However, if glutenin is the only protein
fraction in dough, the dough would be too resistant to
expand during fermentation and baking. To assure good
performance of the dough, gliadin, with its small and
symmetrical molecules must be present to modify the
glutenin.

Gliadins are mixtures of tightly folded globular

31
proteins with hydrophobic regions buried within the
molecules and the hydrophilic H bonding regions exposed on
the surfaces (Mecham, 1973). This structure may explain the
sticky nature of gliadins.

The factors that contribute to the strength of an
adhesive joint (Gent, 1982) range from weak Van der Waals
interactions to covalent chemical bonding, which plays an
important role in the attractive forces at the interface.
Besides these, the dissipative properties of the adhering
materials are also contributing factors. On the other hand,
perfectly-elastic and non-dissipative materials have the
lowest adhesion strength. There are also geometrical
factors in joint strength. When the adhesive layer is
extremely thin, it cannot release much energy in the
internal deformation processes, which keeps its contribution
to the observed strength to a minimum.

The energy required for joint rupture is stored
elastically in the bonded parts (Gent, 1982). When energy
is expended, this makes a small detached region grow in
size. The result of this action shows that the breaking
stress depends upon the elastic properties of the system
(the elastic modules and dimensions of the various
components), and the size of the debonded zone. At least
three sciences contribute to the strength of adhesion:
interfacial chemistry, rheology of inelastic materials, and

the mechanics of fracture of composite systems. The first

32
phase of dough formation primarily involves the moistening
of the flour particles. The movement of the mixer elements
an/or bowl disperses the dough water between the flour
particles. The hydrophilic properties of the particles
cause liquid to be absorbed onto their surface. This
results in the shearing elements of the mixer countering the
forces of adhesion.

2.2.3 Measurement of physical/functional properties of
dough

The most distinctive property of dough made from wheat
flour is its ability to retain the gas formed within its
mass either due to the growth of yeast or the action of an
acid on sodium carbonate (Swanson, 1943). This property
results from the water films absorbed on the filaments of
gluten and the enmeshed starch. There is a certain amount
of elasticity and plasticity in gluten strands, enabling
recoil after stretching and if the stretching goes beyond
the elastic limit, it results in permanent elongation.

The Brabender farinograph is used to measure the water
absorption properties of flour and the mixing
characteristics of a standard flour-water dough. Because of
the complex nature of the functional properties of wheat
flour, an evaluation of wheat flour dough must be performed
under actual or simulated baking conditions. The brabender
farinograph and extensigraph are the basic instruments used
to characterize the gluten proteins under the simulated

conditions existing within the bakeshop.

33
Dough consistency plays an important role in achieving
proper mechanical development. It also influences the gas
retention properties of the dough (Sietz, 1978). Absorption
values are used extensively in the calculations involved in
developing new formulations. Generally, flour with high
absorption values are desired because it increases unit

yields.

2.3. Correlation of measurement in stickiness with food

The force to tear products apart per cross-sectional
area or per unit weight of sample is a function of a
material's tensile strength. Tensile strength was used to
measure the adhesion strength of chunked and molded products
(Trout and Schmidt, 1987). Tensile strength is often
measured using an Instron Universal Testing Machine, or a
device such as the Food Technology Corporation's Texture
recorder, which measures an apparent tensile strength.

The Instron Testing machine was introduced in 1949
(Hindman & Burr) as a general purpose material testing
machine, and is used for testing textiles, paper, plastics,
rubber, and other flexible materials. It is suitable for
laboratory use because of the sophisticated controls and
sensitivity of measurement possible. Its most useful
function is in the application of classical material test
methods to establish fundamental material properties.

The Instron Tensile Tester, model TM (Instron

Engineering Corp., Quincy, M.A.) consists of two horizontal,

34
parallel plates, with a constant rate-of-jaw-separation on
the tap plate. A device attached to the bottom plate
measures the force pressing (positive) or pulling (negative)
against the plate (ASTM D 882-83, 1983). The crosshead is
set and moves at a constant rate during the test. The
stickiness value equals the grams adhesive force and cm
crosshead movement times the appropriate factor.

The Instron Tester is an excellent tool to evaluate
stickiness because it focuses on the surface properties most
desirable to measure. Batcher et al (1963) stated that
cooked rice had similar palatability characteristics no
matter what cooking method or medium was chosen. Ferrel et
a1 (1960) used a screening device constructed so as to
determine if different preparation methologies would change
the rice stickiness. Mossman et a1 (1975) studied different
treatments that accelerated the aging of sticky rice. In
each case the Instron Tester was chosen to measure
stickiness levels and to differentiate the type of
stickiness.

Mossman et a1 concluded that time and water content had
varying impact on the stickiness of the sample. Increasing
cooling time resulted in a small increase in the stickiness
value, while an increase in the amount of cooking water
caused a proportionately greater increase in the stickiness

value.

35

2.3.1 Methods of measurement in stickiness

Cooked spaghetti must be firm, resilient, and nonsticky
to meet maximum consumer acceptance. Voisey et a1 (1978)
used the Instron Universal Tester to measure the stickness
of cooked spaghetti. D'Egidio et al (1982) concluded that
spaghetti stickiness is related to the amount of surface
material that can be washed from drained cooked spaghetti.

Compression testing utilizes a compression cell which
is composed of parallel plates between which test procducts
can be compressed. Apparent stress at failure and apparent
strain at failure can be calculated (Diehl et al., 1979),
while true stress and strain cannot be calculated because a
uniform cylinder is not maintained during compression.
Strain is highly correlated to sensory and texture profile
analysis (TPA) cohesiveness, while stress to fail
(compressive force to failure) is correlated to TPA hardness
and sensory firmness (Montejano et L., 1983).

Dexter et a1 (1980) modified the GRL compression tester
(Kilborn et a1, 1982) to test for cooked spaghetti
stickiness. Dexter's process used sample sizes as small as
6g of spaghetti. The cooked spaghetti was compressed under
a plunger and the force of adhesion of the spaghetti to the
plunger was measured upon lifting the plunger.

Dexter demonstrated that the quality of the cooking
water and spaghetti drying procedure have a significant

influence on stickiness of cooked spaghetti. Spaghetti

36
stickiness is also related to cooking time and elapsed time
after cooking. Other factors such as gluten strength,
sprout damage, semolina granulation, and extrusion
conditions are all associated with cooked spaghetti
stickiness. Dexter concluded that protein content has no
significant correlation to spaghetti stickiness.

Dexter et a1 (1983) studied factors that influence
stickiness and their relationship to other cooking quality
characteristics. He concluded that each spaghetti sample
proved to be stickier and lost more solids during cooking
when cooked in tap water compared to deionized water.
Comparing spaghetti processed under high temperature and low
temperature drying conditions, spaghetti cooked at high
temperature was less sticky. Stickiness was lightly
influenced by cultivar, wheat class, raw material
granulation, and protein content, but was not related to
sprout damage. Even when all the factors were included in a
step-up regression analysis, less than 50% of the variance

in stickiness could be predicted.

Gaines et al (1982) studied the influence of
temperature, humidity, and flour moisture content on
stickiness in sugar-snap cookie dough. Dough stickiness
measurements were conducted with a Struct-O-Graph.
Gaines concluded that the most desirable ambient
conditions for evaluating soft wheat cultivas with the

micro-method III (Finney et al 1950) procedure are

37
temperatures between 20-21°C and 30-50% relative humidity.
This allows "standardization" of dough consistency and also
prevents stickiness problems. No combination of flour
moisture content and dough water absorption level caused
stickiness problems at 21°C and 50% relative humidity. At
optimum dough consistency, doughs made from flours having
high moisture contents were less sticky and easier to work
with because they tolerated changes in the level of dough

water absorption better.

Gaines (1981) used a Struct-O-Graph (C. W. Brabender,
South Hackensack, N.J.) to measure the stickiness of cake
crumb and to find out if flour chlorination correlated with
cake crumb stickiness. A Struct-O-Graph was fitted with a
2,000-cmg spring and a 30-mm diameter plastic disk plunger
that moved at a rate of 132 mm/min. The pen arm was
activated at the 500-BU chart line, when the cake crumb
piece had been compressed for 1 minute, and stopped at the
1,000-BU chart line. At this point compression was relieved
and the stickiness measurement was taken. This can be
described as one compression/stickiness measurement cycle.

When compressing the sample, the pen arm will travel
above the 500-BU line if the sample adheres to the disk and
platen. The distance above the 500 line is recorded as the
amount of crumb stickiness in centimeter grams. The mean of
the stickiness measurements is then calculated. Higher mean

stickiness values indicate greater crumb stickiness.

38

Neither flour chlorination rate nor the flour pH, cake
volume, or batter liquid level were correlated with an
objective stickiness measurement.

Taguchi et al (1979) studied the factors affecting the
adhesion of canned mackerel meat. Measurement of adhesion
consisted of weighing the meats that adhered to the inner
container. Taguchi used the following for his study:
Different retorting time: 80 minutes and 60 minutes
Salt: 2.5% NaCl, 2.5% NaCl + 0.2% pyrophosphate, or 2.5%
NaCl + 0.1% CaClz;

Heating times, 40° to 100°C for 30 minutes.

He concluded that the freshness of the raw meat
influences the degree of adhesion while the heating
temperature affects the formation of adhesion bonds. The
most noticeable adhesion occurred when the internal
temperature reached 60°C. Adhesion increased greatly as the
heating temperature reached 80°C without NaCl or with 2.5%
NaCl. The amount of adhesion greatly decreased with the

addition of CaCl2.

Curley et al (1983) studied the effect of corn
sweeteners on dough stickiness. Dough stickiness was
measured with the Instron Universal Testing Machine (model
1122) in the tension mode. He concluded that the dough with
0% dissolved sucrose was firm and manageable, while the one
with 100% dissolved sucrose was very sticky and

unmanageable. When 50% of the granular sucrose was replaced

39
with High-fructose corn syrup, the resultant dough was as
sticky and unmanageable as the dough made with 100%

dissolved sucrose.

Noguchi et al (1976) studied the correlation of dough
stickiness with various quality parameters. A texturometer
(General Food Corp. New York) was used to determine dough
stickiness and consistency. Dough was mixed with a 1.5%
sodium chloride solution in a pin-type mixer and the dough
was shaped into a sheet (15 x 5 x 1 cm) by the Chopin
alveograph mixer and then set on the texturometer.

Noguchi concluded that dough stickiness correlated very
highly with the sulfhydryl (SH) content of the protein and
with proteinase activity. The protein content, however, did
not correlate with adhesiveness, but possibly those with a
high sulfhydryl content might well be expected get involved.

In the butter industry, the term stickiness refers to
the property which permits butter to remain attached to
solid surfaces. This physical characteristic, which
involves both adhesion and cohesion, has been described by
the term 'hesion' (Claassens, 1958).

Thomasos et al (1963) studied some factors which
influence butter stickiness. He pointed out that the
characteristic crystal structure affected the hesion values,
and homogenization of butters significantly increased hesion
readings. An increase in gas content caused a decrease in

hesion values with more butter remaining on the adherend.

 

40

Thomasos also stated that the crystal structure would change
the adhesive property of butter and the gas content would
influence the cohesive property.

Kumar et al (1975) compared a balance and a sieve to
test the stickiness of cooked rice. Juliano et al (1965)
concluded that stickiness related to the amylose content of
rice. Sanjiva (1938) stated that rice stickiness is
strongly affected by its age, that freshly harvested cooked
rice is moist and sticky, but that aged cooked rice is dry
and flaky.

20 g of cooked rice was placed on the top sieve (6.7
mm). The two sieves were rotated by hand, with a firm tap
at the end of each rotation. After sieving, the rice
retained on each sieve was carefully collected and weighed.
To conduct the adhesion test, 10 g of cooked rice was placed
in a stainless steel cup, gently levelled with a spatula and
then pressed for 4 minutes with a 1.5 kg metal pressure
weight, and passed through a vertical guide to give a
uniform surface. A polished stainless steel cylindrical
test body hanging from the left arm of a balance, and
counter-balanced exactly on the right arm, was then gently
lowered onto the rice and pressed with another small
pressure weight for exactly one minute. The weight was
removed, the balance released, and sand was added in a
stream onto the right pan until the test body was released

from the rice.

41

Kumar came to the conclusion that the sieve test gave a
very good indication of the stickiness of cooked rice. The
adhesion test, although providing indication of the
stickiness of cooked rice had a low correlation and the test
procedures needed further improvement. He concluded that
the consistency of Cooked rice has a negative correlation
with stickiness but the water insoluble amylose content of

rice seemed to have significant correlation.

 

 

CHAPTER 3
MATERIALS AND METHODS
This research is divided into two parts. In part 1,
studies were designed to evaluate the stickiforce meter as a
device to measure adhesion between dough and the contacting
surface. In part 2, studies were designed to characterize
adhesion between plastic films and doughes of different

flour types and protein levels.

3.1 Materials

3.1.1 Flour Samples

A dry mix (flour plus premix), provided by a Pizza
Manufacturing Company, was used for the phase I study. In
the phase II study, three different flours were selected.
Bleached, enriched bromated flour and unbleached, unenriched
pastry flour were purchased from Food stores at MSU. The
flours were manufactured by General Mills, Inc.,
Minneapolis, Minnesota. Premium, high gluten, bleached,
bromated flour was purchased from Food Stores at MSU and
was manufactured by Bay State Milling Co., Quincy, Mass.

3.1.2 Film Samples

Film samples were obtained from several suppliers and

the pizza manufacturing company for phase I study. (Table 1)

In the phase II study, three different films were selected

42

 

43

Table 1. Film samples used in Wettability and Stickiforce

Meter - Phase I study

Material Film thickness

1 HDPE 20 MIL

(High Density Polyethylene)

2 PVC 15 MIL

(Polyvinyl Chloride)

3 PET/RELEASE AGENT 14 MIL

(Polyester)

4 PETG 8 MIL

(Polyethylene Terephthalate Glycol)

5 2% EVA/VEGETABLE OIL 2.5 MIL

(Ethylene Vinyl Acetate)

6 2% EVA/1.5% PAM SPRAY 2.5 MIL

(Ethylene Vinyl Acetate)

7 2% EVA/MYV 9-40 2.8 MIL

(Ethylene Vinyl Acetate)

8 TRI-EXTRUDED PE 0.7 MIL

9 KRAYTON 14.5 MIL

10 60 1b. SEMI-BLEACHED 4.0 MIL
SILICONE COATED RELEASE LINER

11 TEFLON FEP 1.0 MIL

12 SILICONE RELEASED PAPER 3.5 MIL

13 SILICONE ON SUPER *
CALENDARED DENSIFIED KRAFT

14 SILICONE ON CLAY- *

CALENDARED DENSIFIED KRAFT

Sources
DOMINO'S Pizza

DOMINO'S Pizza
DOMINO'S Pizza
DOMINO'S Pizza
DOMINO'S Pizza
DOMINO'S Pizza
DOMINO'S Pizza
DOMINO'S Pizza
DOMINO'S Pizza
MEAD RELEASE
PRODUCTS
DU PONT/DURAFILM
MEAD RELEASE
PRODUCTS
EASTERN FINE
PAPER

EASTERN FINE
PAPER

* Silicone coated materials - thickness unknown

44
to provide a broad range of surface wettability and
morphology (Table 2). Both PET and Teflon films were
obtained from E. I. Du Pont De Nomours & Co., Inc.
(Circleville, Ohio). LDPE film was obtained from Tredegar

Film Products (Manchester, Iowa).

3.2 Analytical Measurements
3.2.1 Determination of the Initial Flour Moisture
Content (IMC)

Moisture analysis were performed on the Hi-protein
flour, bread flour, and pastry flour. Triplicate 2.0
(~2.000) gram samples were weighed on an analytical balance,
then dried to a constant weight in a Hotpack Vacuum Oven,
Model 633 (Hotpack Corp., Philadelphia, PA.) at 80°C in a
partial vacuum of 30 mm of Hg for 6 hours, according to AACC
Method 44-40 (1983).

The dried samples were transferred to a desiccator
until cooled to 25°C and then weighed to the closest 0.0001
gram using a Mettler AE 166 Balance (Mettler Instruments
Corp., Hightstown, N.Y.).

The samples were reweighed to determine weight loss due
to loss of moisture. IMC was determined (dry basis)
according to the equation:

(W1 - Wf) / Wf * 100% = % Dry Wt

Where W1: Initial weight of product sample .
Wf: Final weight of product sample after drying

45

Table 2. Film samples used in Wettability and Stickiforce
Meter - Phase II study

Film Thickness
Low Density Polyethylene (LDPE) 2 MIL
Polyester (PET) 1 MIL
Teflon 2 MIL

3.2.2 Determination of the Protein Content

Protein content of the pastry, bread, and high gluten
flours were performed using the Microkjeldahl method
(according to AACC method 46-13) for total nitrogen
determination. Duplicate 0.5 gram samples were digested in
sulfuric acid, sodium sulfate, and copper sulfate at 400 -
500°C until digestion was completed (#2 hours). Samples
were transferred to a distillation apparatus (Buchii
Kjeldahl Machine, Brinkman Instruments) and distilled
according to AOAC Methods 2.057, 14.026 and 14.068 (1980).
Total protein was calculated based on percent nitrogen in
the sample multiplied by a factor of 5.7.

3.2.3 Determination of the later Absorption Properties

-Parinogaph

Flours were evaluated for water absorption using a

Farinograph, manufactured by C.W. Brabender Instruments,

Inc. (Model PL-ZH, Dynameter number 2092). A Thermobath

46
(Type P 60-B) maintained at 30+/- 0.1°C was used to regulate
temperature of the mixing bowl.
The test was run according to AACC Method 54-21 A
(1983). Moisture content of the pastry, bread, and Hi-

protein flours were determined as described previously.

3.2.4 Stickiforce Meter Determination

Lai et a1. (1985) applied a modified tensile strength
apparatus to measure powder cohesiveness. Similar principle
was used by Lai in developing the Stickiforce Meter.

The base, dough holder cube, and cube stopper were
constructed from plastic (Acrylic)(Fig. 2). The cube was
open at both ends. During measurement, a small piece (2" x
2.5“) of test film surface is placed under the cube opening.
The cube is then filled with dough sample (~27.5 g) and
placed sideways against the stopper of the apparatus. The
test film material is attached to a string with a small cup
at the other end. The test film surface is made to break
away from the dough surface by the weight of water added
into the cup from a burette (50ml). The weight-force per
unit area of separation (Wtforce) is recorded. In addition,
the weight of the contact surface before and after each test
was also measured. This was reported as weight-mass per
unit area (thass).

3.2.5 Inclined Plane Determination

The wettability of a surface can be determined by the

sliding of a drop of fluid along a tilted surface (Kawasaki,

47

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

// /;4/
M 7

 

/

 

 

 

 

Figure 2. Diagram of Stickiforce Meter.

Components: 1. Base (Acrylic) 2. Dough holder cube 3. Test film
4. Burette 5. Burette holder 6. Cup
7. Cube stopper

48
1960; Bikerman, 1966). The tilted plane procedure described
by Lai (1988) was adapted for use in this study (Fig. 3).
It provided a measure of the wettability of the plastic
surface. A droplet of distilled water and 50% ethyl alcohol
were placed separately on the test surface which lay on a
horizontal platform. The droplet was allowed to spread
until arrest occurred. The platform was then carefully
tilted at a rate of one degree per second. Angle of slide
was defined as the limiting angle between the platform and
the horizontal plane at which the droplet moved at a uniform

rate of one degree per second.

3.3 Experimental Design
3.3.1 Phase I Study

Studies were designed to evaluate the stickiforce meter
as a device to measure adhesion between dough and the
contacting surface. The Stickiforce meter was then used to
determine if different dough temperature and contacting
films would effect sticking of dough to film. Films (Table
2) were cut into 1" x 8" strips using a JDC Precision
Sample Cutter Model JDC 25 (Thwing - Albert Instrument
Company, Philadelphia).

Fresh dough was prepared by weighing out 0.91 grams of
active dry yeast, and 481 grams of 35°C tap water. A small
portion of the water was slurried with the dry yeast in a

mixing bowl. One package of the prepared dry mix (flour

49

Plastic Film

    
     
 

J

°‘~ - angle of the tilt

Figure 3. Sliding of a drop of fluid along tilted plane.

50
plus premix) was then added to the bowl, along with the
remaining water. These materials were then mixed in a
Kitchen Aid K-Sss Mixer (Hobart Corporation, Troy Ohio,
speed range 2) at room temperature for seven minutes or
until the dough was fully developed. After development, the
surface was dry and shiny and the texture very fine. When
the dough was stretched by hand, there was a good deal of
elasticity and stretchiness.

Treatment Variables

A. Fresh prepared dough was placed in contact with
film surface. Following refrigeration (4°C) for 24 hours,
each sample was allowed to reach ambient temperature (23°C)
and proofed to twice its original size (approximately 4
hours) before performing the Stickiforce Meter Measurement.

B. Same as treatment A except that the dough was put
inside a plastic bag (LDPE) under refrigeration for 24
hours. The dough was then placed into contact with the film
surface, and proofed to double its size before performing
the Stickiforce Meter Measurement.

C. Same as treatment A except that dough was not
refrigerated. Stickiforce Meter Measurement was performed
after the dough was proofed to twice its size (approximately
2.5 hours) at ambient temperature (23°C).

D. Fresh dough was proofed first at room temperature
(23°C) and then placed in contact with the film surface for

Stickiforce Meter Measurement.

51
These four treatment combinations were arranged in a 2
x 2 factorial design. The effect of yeast condition
(proofing), and temperature were evaluated, as well as the
interaction of these factors. A split plot design was used.
Treatment variables served as the whole plot factor and film

as the split of a randomized complete block design.

3.3.2 Phase II Study

Studies were designed to characterize adhesion between
plastic films and doughes of different flour types and
protein levels (Fig. 4). Several plastic packaging
materials were selected from Part 1 to provide a broad range
of surface wettability.

Flour of different protein and starch contents were
obtained and blended with water to form model
systems. These were deposited onto the surface of selected
packaging materials. The influence of protein concentration
on adhesion was also determined. In addition, the flour
protein was fractionated and studies of adhesion conducted
with individual proteins.

Dough was also prepared at several protein
concentrations and adhesion characterized for fresh dough,
refrigerated, and proofed dough systems.

Dough Preparation

Three-hundred grams of flour were mixed in a Kitchen
Aid K-SSS mixer (Hobart Corporation, Troy Ohio) at room

temperature. Red Star quick-rise active dry yeast (1%) was

r—gi

56:35:39.. .2591 .

 

 

loan—Nb \ Pm.— \ mm

 

133m >~=h<m \ 8:3".— emxn \ 8:3"— ZEOIAZI

 

lav-mun 12.—Elma a macar—

g g g g
g 58: g.— g E 83—5-8 E 83—28
. .g g an .80 g 458 .3 :8 amps-mg dab;
53588 50:06 5588 Paint—~88 :82 IE :82 lg
gal—=3:
HOBO.—
HOSP-g

53
purchased from Food Stores at MSU (Red Star Yeast &
Products., Milwaukee, Wisconsin) and was dissolved in
distilled water. The amount of water used in making of the
dough was determined from farinograph absorption. These
ingredients were then mixed for three to seven minutes,

depending upon the protein content.

Treatment Variables

E. Fresh dough was first put into a container,
following refrigeration (4°C) for 6 hours. The dough was
allowed to reach ambient temperature (23°C) and proofed to
twice its original size (approximately four hours). Then
it was placed in contact with the film surface prior to
preforming the Stickiforce Meter Measurement.

F. Fresh prepared dough (with yeast) was first
allowed to proof to double its size (approximately two and
half hours) at room temperature (23°C). Then it was placed
in contact with the film surface for Stickiforce Meter
Measurement.

G. Fresh prepared dough (with yeast) was placed in
contact with film surface. Following refrigeration (4°C)
for 6 hours, each sample was allowed to reach 23°C and
proofed to twice its original size (approximately four
hours) before performing the Stickiforce Meter Measurement.

H. Same as treatment G except that it was not
refrigerated. Stickiforce Meter Measurement was performed

after the dough was proofed to twice its original size

54
(approximately two and half hours).

I. Fresh prepared dough (no yeast) was placed in
contact with film surface. Following refrigeration (4°C)
for 4 hours, each sample was allowed to reach room
temperature (23°C) before performing the Stickiforce Meter
Measurement.

J. Same as treatment B except that it was not
refrigerated. Stickiforce Meter Measurement was performed
after the dough was made.

The six treatment combinations were arranged in a 3 x 2
factorial design. The main effects were yeast condition
(proofing), and temperature, as well as the interaction of
these factors. Treatments served as the main plots, film as
the sub-plots, and the flour type as the sub-subplots of a

randomized complete block split—split plot design.

3.4 Statistics Analysis

3.4.1 Phase 1

Statistical analyses were performed on a CompuAdd 212
computer utilizing MSTAT-C statistical packages
(Microcomputer Program for the Design, Management, and
Analysis of Agronomic Research Experiments). The two
factor randomized complete block, split plot for data was
computed using a MSTAT ANOVA procedure. Differences between
means were determined using the Tukey's Honestly Significant

Difference Test method.

55

3.4.2 P1138. II

All statistical analyses were performed on a CompuAdd
212 computer utilizing MSTAT-C statistical packages
(Microcomputer Program for the Design, Management, and
Analysis of Agronomic Research Experiments). The two factor
randomized complete block split-split plot for data was
computed using an MSTAT ANOVA procedure. Differences
between means were determined using the Tuckey's Honestly

Significant Difference Test method.

CHAPTER 4

RESULTS AND DISCUSSION

4.1 Phase I study

4.1.1 Inclined Plane Determination

Surface chemists use the term "wettability" or
"wetting" to describe the degree of adhesive contact between
liquid and solid. In this study, angle of slide was
employed to measure the wettability of the film surface.
Table 3 presents the results obtained.

The angle of slide ranged from 24.6 to 46.0 degrees for
the surfaces studied. The smallest angle of slide required
to move the water droplet was on the Teflon surface (24.6°).
The small angle indicates poor wetting of the material by
the water. On the other hand, the angle required for the
water droplet to slide on the PETG surface was almost double
that of the Teflon (46.0°).

4.1.2. Stickiforce Meter Determination

The dough was made of high protein wheat flour. Dough
is a rather sticky and elastic substance once it is fully

developed. Table 4 shows the effect of dough treatments on

the weight-mass (thass) gained (per unit contact area) as

determined by the Stickiforce procedure. Treatment A

56

57

Table 3. Wettability of distilled water and 50% ethyl
alcohol on different material surfaces (Phase I
study).

Distilled water 50% ethyl alcohol
ngple Angle of slide,” Angle of slide

Machine Cross Machine Cross

Dir—Leo - Hirsch; m Direct;

HDPE 41.812.04 41.412.15 34.412.45 34.211.60

PVC 39.813.32 41.512.68 28.611.85 34.011.60

PET/RELEASE 30.311.67 35.211.94 30.011.83 34.8:2.32

AGENT

PETG 46.011.72 43.0i2.24 31.8i1.62 37.213.61

(Polyethylene
Terephthalate
Glycol)
2% EVA/VEGETABLE 26.010.63 29.416.95 42.411.36 39.013.72
OIL
2% EVA/1.5% PAM 29.313.66 28.611.47 42.8:0.98 42.012.45
SPRAY
2% EVA MYV 9-40 23.012.28 20.010.63 26.411.02 30.411.20
RELEASE ADDED
KRAYTON 31.511.94 28.612.80 29.816.37 27.4i4.3l
TRI-EXTRUDED PE 38.812.80 38.814.36 37.313.71 40.214.47
HIGH SLIP

ISO-60*3 35.411.36 37.4i1.94 22.812.28 26.6:2.14

TEFLON 24.611.02 22.5i0.80 21.5il.67 22.511.33

SILICONE PAPER 38.011.20 37.311.20 22.310.98 25.510.80

80C146A”4 41.511.60 39.011.50 27.810.98 23.612.58

78G98fl'5 40.811.20 45.512.50 22.3io.80 28.311.36

*1 The direction of forward movement on the paper/plastic

* machine. . . .
2 The direction at right angles to the direction of running

paper/plastic machine. .

*3 60 lb. Semi-bleached Silicone Coated Release Liner
*4 Silicone on Super-calendared Densified Kraft
Silicone on Clay-calendared DenSIfied Kraft

58

Table 4. The effect of treatment on the Weight-mass gain
per unit (gm/cmz) determined by Stickiforce Meter

TBEAIMEH‘I (Unit = 10‘3)

Sample A B Q Q

HDPE 71.90:34.63 0.31:0.32 1.5210.63 0.50:0.35

PVC 102.71i59.03 7.2114.36 0.9510.35 0.5010.33

PET/RELEASE 44.78i35.82 1.61i0.53 1.1010.28 1.09:0.58
AGENT

PETG 182.75142.69 1.6915.33 0.9210.29 1.09:0.21

2% EVA/VEG 11.11112.29 1.23:0.48 0.57:0.19 0.26:0.53

OIL

2% EVA/1.5% 1.14:0.53 0.6910.15 0.9611.15 0.21i0.12
PAM SPRAY

2% EVA/MYV 1.49:0.76 1.0910.60 0.48:0.17 0.2210.10
9-40

TRI-EXTRUDED 0.93:0.59 0.82:0.16 0.50:0.26 0.4310.23
PE

KRAYTON 2.2010.77 1.30:0.23 0.8410.09 0.56:0.16

ISO-60 122.941256.78 7.92:2.95 5.03:2.26 2.53i2.01

TEFLON 1.5710.36 0.8210.17 0.33:0.08 0.17:0.12

SILICONE 85.451161.97 4.8311.95 3.45i0.76 2.1410.80
PAPER

80C146A 14.61i11.28 6.7712.93 2.43:0.84 2.51:3.85

78698 78.27:139.53 23.84126.44 6.89:4.23 23.42i1.38

*A. Dough was placed in contact with film surface.
Refrigerated (4°C) for 24 hours, each sample was allowed to
reach ambient temperature (23°C) and proofed to twice its
Original size before performing the test.

*B. Dough was placed inside a plastic bag (LDPE): _
refrigerated for 24 hours. The dough was then placed into
contact with the film surface, and proofed to double its

size before performing the test.

*C. Dough was placed in contact with film surface. Test was
performed after the dough was proofed to twice its Size at
ambient temperature (23 C).

*D- Dough was proofed first at room temperature (23°C) and
then placed in contact with the film surface for the test.

59
samples (dough was placed in contact with film surface,
refrigerated for 24 hours, allowed to reach room temperature
and proofed to twice its original size before performing the
test) had the highest thass per unit area for all contact
surfaces (Table 4). This suggests that cooling and proofing
of the dough may enhance the sticking phenomenon. With
thass equal to 0.15 x 10'3, Teflon was found to be the best
surface for good release of dough. The smaller the angle
the less the dough adhered to the film surface.

Weight-force (Wtforce) per unit area data obtained from
the Stickiforce Meter is listed in Table 5. Wtforce results
were correlated with the thass results (R2 = 7.24).
Treatment A had highest Wtforce values. This showed that
treatment A produced the most dough adhesiveness. In
general, Teflon and 2% EVA film with vegetable oil were
found to have the least adhesiveness to dough (Inclined
Plane method and Stickiforce Meter method). The films
studied in Phase I are listed in Table 6 in order of their
stickiness to dough. A ranking of 1 was considered to have
the best release properties.

Adhesion of dough to a contact surface can sometimes be
avoided by the use of 'adhesives', such as release agents.
These are added to resins or used as coatings which are
applied to a solid to prevent, or decrease, adhesion of
another solid. For example, sample 5 (2% EVA) had a layer

Of vegetable oil on its surface, or sample 7 (2% EVA) had

Table 5.

60

The effect of treatment on the Weight- -force gain

per unit (gm/cm2 ) determined by Stickiforce Meter

Sample
HDPE

PVC

PET/RELEASE
AGENT
PETG

2% EVA/VEG
OIL

2% EVA/1.5%
PAM SPRAY

2% EVA/MYV
9-40

TRI-EXTRUDED
PE

KRAYTON

ISO-60

TEFLON

SILICONE PAPER

80C146A

78698

*

A
15.0712.35

21.2116.37
19.1316.35
25.89i4.88
11.4816.83
5.04i1.95
4.2011.29
4.0212.65
7.15:1.84
23.8917.06
3.0110.61
24.9915.45

16.60i5.78

TREATMENT

2* c
6.Slil.él 3.5911.51
4.68:2.79 3.51:1.63
6.40:2.97 5.74:1.36
4.28:2.07 5.9411.54
6.8412.96 3.8110.95
3.4211.00 3.60:0.71
2.3211.23 3.00:1.22
3.3210.84 3.1610.81
3.80:1.01 3.7010.65
12.53i3.37 12.18:4.15
2.17:0.69 3.3110.74
22.83:6.47 14.2511.86
16.44:4.9l 10.28:2.51

*

D
3.20:1.34

4.21:1.43
4.18:1.41
4.76:1.04
2.9810.66
3.39:1.58
2.6410.91
2.93:0.53
3.4810.63
8.20i2.76
2.52i0.59
10.68i2.36

7.8911.64

28.1914.78 12.96i3.02 13.4211.75 10.5011.73

*A. Dough was placed in contact with film surface.
Refrigerated (4°C) for 24 hours, each sample was allowed to
reach ambient temperature (23°C) and proofed to twice its
original size before performing the test.

*B. Dough was placed inside a plastic bag (LDPE),

refrigerated for 24 hours.

*C. Dough was placed in contact with film surface.
performed after the dough) was proofed to twice its size at

ambient temperature (23C

The dough was then placed into
contact with the film surface, and proofed to double its
size before performing the test.

Test was

D. Dough was proofed first at room temperature (23°C) and
then placed in contact with the film surface for the test.

61

Table 6. Ranking of dough stickiness to films samples with
different treatments, the rank of 1 was considered
to have the best release properties.

G MASS GRAM FORCE
Sample * TREATMENT * * TREATMENT *
A B C D A B C D

HDPE 9 1 10 6 7 9 5 5
PVC 12 12 7 7 10 7 4 9
PET/RELEASE AGENT 8 8 9 9 9 8 9 8
PETG 14 9 6 10 13 6 10 10
2% EVA/VEG OIL 6 6 4 4 6 10 8 4
2% EVA/1.5% PAM 2 2 8 2 4 4 6 6
2% EVA/MYV 9-40 3 5 2 3 3 2 1 2
TRI-EXTRUDED PE 1 4 3 5 2 3 2 3
KRAYTON 5 7 3 5 5 5 7 7
ISO-60 13 13 13 13 11 11 12 12
(SILICONE COATED)

TEFLON 4 3 1 1 1 1 3 1
SILICONE PAPER 11 10 12 11 12 14 14 14
80C146A 7 11 11 12 8 13 11 11
(SILICONE COATED)

78G98 10 14 14 14 14 12 13 13

(SILICONE COATED)

A. Dough was placed in contact with film surface.
Refrigerated for 24 hours, each sample was allowed to reach
ambient temperature (23°C) and proofed to twice its original
size before performing the test.

*B. Dough was placed inside a plastic bag (LDPE),
refrigerated for 24 hours. The dough was then placed into
contact with the film surface, and proofed to double its
size before performing the test.

*C. Dough was placed in contact with film surface. Test was
performed after the dough was proofed to twice its size at
ambient temperature (23 C).

*D. Dough was proofed first at room temperature (23°C) and
then placed in contact with the film surface for the test.

62

MYV 9-40 release agent added to its surface. To minimize
adhesion of dough to its container, there should be a high
degree of wetting of the contact surface with oil or a
release agent and a low degree of wetting of the oil surface
in contact with the water and dough.

4.1.3 ltforce/ltmass Results

The effects of temperature, yeast condition and film on
Wtforce and thass were studied. Mean squares from the
analyses of variance of Wtforce and thass values are given
in Table 7 and 8. Each film has its own characteristics and
wettability. A small angle of slide indicates poor I
wettability of the material. Angle of slide varied
significantly among films with different coating materials -
silicone release agent, pam spray, vegetable oil, and MYV 9-
40 - and different surface polarities). The type of film
had significant effect on both measures of thass (F =
2.190, p = 0.019) and Wtforce (F = 69.605, p = 0.000).
mama

Tukey's Honestly Significant Difference test result of
thass (Appendix B, Table 15) indicates that there was no
significant difference among all films. Tukey's method
provides for the comparison of any or all pairs of treatment
means after observation of the data with a probability of
falsely rejecting the hypothesis of equality on at least one
comparison equal to a probability a. It's a much more

conservative method compared to other methods (Mendenhall,

63
Table 7 Analysis of variance for Wtforce values of 14

different films under different yeast conditions
at various temperature.

Source of Degree of Sum of Mean F P
variation freedom squares Square values

Film (F) 13 8200.200 630.785 69.6046 0.0000**
Replic (F) 70 684.676 9.781 1.0793 0.3752
Yeast (Y) 1 1524.532 1524.532 168.2262 0.0000**
FY 13 1044.181 80.322 8.8632 0.0000**
Error 70 634.368 9.062

Temp. (T) 1 2651.489 2651.489 312.6570 0.0000**
FT 13 1282.947 98.688 11.6371 0.0000**
YT 1 745.479 745.479 87.9051 0.0000**
FYT 13 974.941 74.995 8.8433 0.0000**
Error 140 1187.271

Total 335

* represent p < 0.01

Table 8 Analysis of variance for thass values of 14
different films under different yeast conditions
at various temperature.

Source of Degree of Sum of Mean F P
variation freedom squares Square values

Film (F) 13 0.073 0.006 2.1900 0.0188*
Replic (F) 70 0.182 0.003 1.0793 0.4674
Yeast (Y) 1 0.048 0.048 18.9208 0.0000**
FY 13 0.061 0.005 1.8434 0.0529
Error 70 0.179 0.003

Temp. (T) 1 0.059 0.059 23.3396 0.0000**
FT 13 0.066 0.005 2.0173 0.0234*
YT 1 0.045 0.045 18.0728 0.0000**
FYT 13 0.060 0.005 1.8406 0.0424*
Error 140 0.352 0.003

Total 335

represent p < 0.05

** represent p < 0.01

64
1968). This might explain why it may contradict the ANOVA
results.

When a contact-first-yeast dough starts to proof, the
air bubbles formed from inside the dough gradually separate
the dough from the film. When dough developes to double its
original size, the dough on the top of the film becomes
loose, and easier to pull from the film. Proof-first-yeast
dough was developed and fermented. It was then put onto the
film so that the bonding between dough was tighter than
contact-first-yeast dough.

The interaction between film type and yeast condition
was not significantly different (F = 1.843, p = 0.053) for
thass (Fig. 5). As the figure shows, thass values of
proof-first-yeast dough were higher than those of contact-
first-yeast dough, and PETG/Proof-first had the highest
thass among all tested. For the films PETG, ISO-60, PVC,
and silicone paper, the differences between proof-first and
contact-first yeast dough were greater than the rest of the
films. There were only slight differences between proof-
first and contact-first yeast doughes for: EVA film with
different release agent, krayton, Teflon, and tri-extruded
PE. However, Tukey‘s more conservative Honestly Significant
Difference test result of thass values (Appendix B, Table
16, Fig. 6) indicates that there were no significant
differences for film and yeast interaction.

Temperature has significant effect on dough stickiness.

 

 

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66
Significant differences were found between refrigerated
dough and room temperature dough for thass (F = 23.340, p =
0.000). After the dough was mixed at room temperature
(23°C), it was then put in the refrigerator (4°C) for 24
hours. When the dough was taken out of the refrigerator it
may have become drier. When the dough was removed from the
refrigerator and left at room temperature, sweat appeared on
the surface of the dough, the cold surface causing
condensation to occur. This condensation maybe at least
partially why the dough was more sticky.

The effect of film type varied between the two
temperature conditions. The thass values at refrigerated
temperature are higher than those at room temperature (Fig.
7). Figure 7 shows that PETG at refrigerated temperature
has the highest thass value of all films tested. Silicone
coated materials (i.e., silicone release paper, ISC-60,
80C146A, and 78698), PETG, PVC, HDPE, and PET films had the
next highest values. However, Tukey's Honestly Significant
Difference test results of thass values (Appendix B, Table
17, Fig. 8) indicated that effect of film type did not vary
by temperature.

The effect of yeast (proofing condition) on thass (F =
18.073, p = 0.000) also depended on temperature (Fig. 9).

The mean values of thass at refrigerated temperature (4°C)

were higher than those at room temperature (23°C), and the

means of thass of proof-first-yeast dough were higher than

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69
those of contact-first-yeast dough. Tukey's Honestly
Significant Difference test results of thass (Appendix B,
Table 18, Fig. 10) indicates that there was no significant
difference for temperature and yeast interaction.

A three-way interaction of film, yeast, and temperature
was significantly different (F = 1.841, p = 0.042) for
thass. This three-way interaction is illustrated in Figure
11, and 12. Dough stickiness varied when either yeast
condition, temperature, or film type changed. Different
films have different wetting characteristics because of
difference surface polarities. Yeast condition and the
change of temperature caused variation in the stickiness.

In general, stickiness was higher for dough at
refrigerated temperature (4°C) than for dough at room
temperature (23°C), and stickiness was higher with proof-
first-yeast dough than with contact/first-yeast dough.
However, there was an exception. The thass value for
80C146A (silicone on super-calendared densified kraft) for
contact-first-yeast dough was higher than those for proof-
first-yeast dough at room temperature. The thass values at
refrigerated temperature with proof-first-yeast dough are
higher than those at room temperature with contact-first-
yeast dough. Proof-first-yeast dough on PETG at
refrigerated temperature (4°C) had the highest thass value
among all film samples, and contact-first-yeast dough on

Teflon at room temperature (23°C) had the lowest. Tukey's

70

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71
Honestly Significant Difference test results of thass
values are listed in Appendix B, Table 19.

Proof-first and contact-first yeast dough had the same
amount of yeast and the same fermentation time, but appear
to yield totally different results. The reason could be
that after contact-first-yeast dough reached full maturity,
the web structure reveals thin-walled gluten strands that
were dry and mellow and offered minimum resistance to
stretching when pulled. Proof-first-yeast dough reached a
fully fermented stage, and was then put in contact with the
films and the test (Stickiforce Meter) was performed
immediately. Thus, there wasn't any opportunity to bring
about a relaxation of the stresses created within the dough
by the mixer action. Apparently, the lack of a second
fermentation period resulted in these stresses not being
released. This may be the reason why proof-first-yeast
dough proved stickier than contact-first-yeast dough.
Wtforcg

The type of film has significant effect on dough
stickiness. Significant differences were found among all
films for Wtforce (F = 69.605, p = 0.0000). Tukey's
Honestly Significant Difference test result of Wtforce
(Appendix B, Table 20) indicated that there was no
significant difference among HDPE, PVC, PET, and PETG; no
significant difference among PETG, 2% EVA/OIL, 2% EVA/PAM,

2% EVA/MYV, Tri-extruded PE, Krayton, and ISO-60; and there

72
was no significant difference among 2% EVA/MYV, Tri-extruded
PE, Krayton, ISC-60, Teflon FEP, Silicone released paper,
80C146A, and 78698.

The interaction between film type and yeast condition
was highly significant (F = 168.226, p = 0.000) for Wtforce
(Fig. 13). The effect of film type or yeast conditions on
the Wtforce value is dependant on each other. As figure 13
shows, Wtforce values of proof-first-yeast dough were higher
than those of contact-first-yeast dough. Wtforce values for
78G98/Proof, PETG/Proof, ISC-60/Proof, and Silicone released
paper/Proof were higher than the rest. Apparently, the
silicone release agent didn't function properly.

Tukey's Honestly Significant Difference Test Result of
Wtforce values (Appendix B, Table 21, Fig. 14) indicated
that there was no significant difference among 78G98/Proof,
PETG/Proof, Silicone/Proof, ISC-60/Proof, Silicone/Contact,
and 80C146A/Proof, no significant difference among
PETG/Proof, 80C146A/Proof, PET/Proof, PVC/Proof,
80C146A/Contact, 78G98/Contact, ISC-60/Contact, and
HOPE/Proof. Also there was no significant difference among
EVA/OIL/Proof, Krayton/Proof, PET/Contact, EVA/OIL/Contact,
HDPE/Contact, PETG/Contact, PVC/Contact, EVA/PAM/Proof,
Krayton/Contact, EVA/MYV/Proof, Teflon/Proof,
Tri/PE/Contact, EVA/MYV/Contact, and Teflon/Contact.

The materials (Table 1) can be categorized into four

groups. The EVA films with different coating materials

w'r-roncn (salon-89)

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74
(coated with vegetable oil, 1.5% pam spray, and myv 9-40),
Teflon, Krayton, and tri-extruded PE high slip film as good
release materials, PET with release agent as medium release
material, silicone release agent coated materials (silicone
released liner, silicone on super-calendared densified
kraft, and silicone on clay-calendared densified kraft), and
HDPE, PVC, and PETG as poor release materials.

MYV 9-40 is a grouping of food emulsifiers, dough
strengtheners, and softeners, coatings. It consists of
texturing/aerating agents, and lubricants, made of edible
lard. Liquid MYV 9-40 materials are used to stabilize the
viscosity of chocolate-flavored syrups. MYV 9-40 can
provide a bland, edible, protective coating on food products
to improve their shelf life, texture, appearance, and
stability. They are waxy rather than greasy, and have
extremely good oxidative stability and good oxygen and
moisture barrier properties. When a 0.25 percent level of
MYV 9-40 was sprayed on dates and raisins, it reduced their
stickiness for easier handling in automatic equipment. Also
these agents can be sprayed on food as surface lubricants
and on processing equipment for use as a lubricant or
release agent (Eastman Chemicals, 1986).

Silicone is widely used as a release coating on plastic
film label stock. Small amounts of specific silicones are
used as internal and external mold release agents, process

aids, and flame retardants in thermoplastics (Bafford,

75
1987). In our study, the materials coated with silicone
release agents were quite sticky compared with other groups
of materials, and the reason is unknown.

PVC, PET, and PETG all have very polar surfaces.
According to Young (1805), surface tensions exist at the
phase boundaries of a drop of liquid at rest on a solid
surface (Fig. 1). If the molecules that make up the surface
are more polar, the surface is easier to wet and bond with a
polar liquid adhesive. PET film was treated with release
agent to decrease its stickiness. HDPE film is not as polar
as PVC and PETG.

Temperature has significant effect on dough stickiness.
Significant differences were found between refrigerated
dough and room temperature dough for Wtforce (F = 312.657, p
= 0.000). After the dough was mixed at room temperature
(23°C), it was then put in the refrigerator (4°C) for 24
hours. As a result, when the dough was taken out of the
refrigerator it may have been drier than when it was put
into the refrigerator. When the dough was removed from the
refrigerator and left at room temperature, sweat appeared on
the surface of the cold dough, causing condensation to
occur. This condensation may have been the reason why the
dough was more sticky.

The effect of film type varied between the two
temperature conditions. The Wtforce values at refrigerated

temperature were higher than those at room temperature (Fig.

76
15). Figure 14 shows that 60 lb. semi-bleached densified
kraft film (ISC-60) at refrigerated temperature had the
highest value among all tested. Tukey's Honestly
Significant Difference test results of Wtforce values
(Appendix B, Table 22, Fig. 16) indicated that temperature
had different effects on the different films.

The effect of yeast condition on Wtforce (F = 7.905, p
= 0.000) also depended on temperature (Fig. 17). The mean
values of Wtforce at refrigerated temperature (4°C) were
higher than those at room temperature (23°C). The means of
Wtforce values for proof-first-yeast dough were higher than
those of contact-first-yeast dough. Tukey's Honestly
Significant Difference test results of Wtforce (Appendix B,
Table 23, Fig. 18) indicated that proof-first-yeast dough at
refrigerated temperature differed significantly from others.

A three-way interaction of film, yeast, and temperature
was highly significant (F = 8.843, p =0.000) for Wtforce.
This three-way interaction is illustrated in Figure 19 and
20. Dough stickiness varied when either yeast condition,
temperature, or film type changed. As discussed above,
different films have different wetting characteristics.
Stickiness varied with yeast condition and the change in
temperature.

In general, stickiness values were higher with proof-
first-yeast dough than with contact/first-yeast dough.

Stickiness values were higher when dough was stored at

77

 

 

 

 

 

 

 

 

 

 

 

 

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80
refrigerated temperatures than when dough was stored at room
temperatures. However, there were a few exceptions. For
PVC, the Wtforce value for contact-first-yeast dough was
higher than those for proof-first-yeast dough. The Wtforce
values at refrigerated temperature (4°C) with proof-first-
yeast dough were higher than those at room temperature
(23°C) with contact-first-yeast dough. Proof-first-yeast
dough on 78698 at refrigerated temperatures had the highest
Wtforce values and contact-first-yeast dough on Teflon at
refrigerated temperature had the lowest Wtforce values among
all tested. Comparing the Wtforce mean values with
different factors, silicone coated materials had the highest
Wtforce mean values. Tukey's Honestly Significant
Difference test results of Wtforce values are listed in

Appendix B, Table 24.

4.2. Phase II study

4.2.1. Inclined Plane Determination

In this study, the wettability of the film surface was
also determined using a modified, inclined plane apparatus.
Table 9 presents the results obtained for the different film
systems. The resultant angle of slide for the surfaces
studied ranged from 25.1 to 33.8 degrees. Teflon film had
the smallest angle of slide (25.1°). This indicates poor
wetting of the material. The PET surface had the largest

angle of slide (33.8°).

81

Table 9. Wettability of distilled water and 50% ethyl
alcohol on different material surfaces.

Distilled water 50% ethyl alcohol
WW W
Machine Cross Machine Cross
Direct, nirggty Direct, Direct.
LDPE 29.911.92 29.8:2.04 24.912.26 26.3:2.93
PET 33.8il.94 32.9:2.26 32.3:2.14 32.013.07
TEFLON 25.112.46 25.7i1.40 22.3i0.87 23.911.28

4.2.2 % Protein in Flours

Doughes of different protein concentrations were
prepared by mixing water with flours of different protein
contents. The amount of protein in the three different
flours is shown in Table 10.

Based on the results of the Farinograph measurements,
water (Appendix A) was mixed into the flour systems to
optimize dough consistency. Dough mixing time was also
optimized using the results of the Farinograph evaluation.
Doughes from each of the different flour mixtures were then
applied to the three test films (Teflon, PET, and LDPE) and
tested for Wtforce and thass as previously described.

4.2.3. stickiforce Hater Determination
The doughes were made of Hi-protein, bread, and pastry

flour. Table 11 shows the effect of dough treatments on the

82

Table 10. The percentage protein in pastry, bread and Hi-

protein flours - determined using Microkjeldahl
method.

W .LL_9_rot in
Pastry Flour 8.76
Bread Flour 13.05

Hi-protein Flour 14.81

83

Table 11. The effect of treatment on the Weight-mass gain
per unit (gm/cmz) determined by Stickiforce Meter

W (Unit = 10'1)

IBEAIHEHI L923 231 IEELQH
E* 2.16:1.24 3.19:0.71 0.20:0.42
F* 2.1911.20 2.9610.73 0.29:0.27
0* 0.94:1.32 1.72:0.48 0.22:0.26
H* 2.2811.25 2.04:2.27 0.37:0.20
1* 6.38:1.52 3.95:1.13 2.09:0.63
J* 6.8311.13 4.2710.97 2.53:0.53

E*. Dough was put into a container, refrigerated (4°C), then
was allowed to reach room temperature (23°C) and proofed to
double its original size. Then it was placed in contact
with the film surface prior to the test.

F*. Dough (with yeast) was first proof to double its size at
room temperature. Then it was placed in contact with the
film surface prior for test.

6*. Dough (with yeast) was placed in contact with film
surface. Refrigerated, then each sample was allowed to
reach 23°C and proofed to double its size prior to the test.

H*. Dough (with yeast) was placed in contact with film at
room temperature. Test is performed after the dough was
proofed to twice its original size.

I'. Dough (no yeast) was placed in contact with film
surface. refrigerated for 4 hours, then was allowed to
reach room temperature before performing the test.

J'. Dough (no yeast) was placed in contact with film
surface. Test was performed after the dough was made.

84
weight-mass gained (per unit contact area) as determined by
the stickiforce procedure. Treatment J (no-yeast dough
contact with film surface, test was performed after the
dough was made) had the highest weight-mass values for all
contact surfaces. This suggests that dough made without
yeast and held in contact under refrigerated temperature
(4°C) had enhanced adhesion.

The fully hydrated protein of a mixed and kneaded dough
forms a veil-like film over the external surface of starch
granules. The fractured surface of the inside of the dough
exposes many cleaved starch granules embedded in a protein
matrix with numerous microscopic holes (Christianson, 1975).
After fermentation, this protein lattice structure shows
larger air cells. Many of the small air cells enmesh minute
starch granules within them. The veil-like protein coating
on the surface of the starch granules, stretches and rolls
up into fibrils due mainly to an increase in the size of the
air cells. This may have caused the yeast doughes to be
less sticky than the no-yeast doughes.

Wtforce per unit area data obtained from the
Stickiforce Meter is shown in Table 12. For both PET and
Teflon film, treatment J had the highest Wtforce per unit
area studied for all the contact surfaces. However, for PE
film, treatment I (no-yeast dough contact with film,
refrigerated, equilibrated to 23°C) had the highest Wtforce

values.

85

Table 12. The effect of treatment on the Weight-force gain
per unit (gm/cmz) determined by Stickiforce Meter

.EILM_§AM£LE
IBEAIMEEI RE 221 EFLON
E* 34.93i8.54 35.12:8.08 20.73:7.37
F* 34.93:10.98 34.39:11.57 20.18:7.95
0* l4.69i7.67 17.7217.27 10.56:8.58
H* 20.8519.52 20.06:10.60 12.67i6.01
1* 53.24:9.31 49.86:7.33 37.3915.93
J* 50.18i6.47 50.0716.35 38.05i5.46

E*. Dough was put into a container, refrigerated (4°C), then
was allowed to reach room temperature (23°C) and proofed to
double its original size. Then it was placed in contact
with the film surface prior to the test.

F'. Dough (with yeast) was first proof to double its size at
room temperature. Then it was placed in contact with the

film surface prior for test.

6*. Dough (with yeast) was placed in contact with film
surface. Refrigerated, then each sample was allowed to
reach 23°C and proofed to double its size prior to the test.

H*. Dough (with yeast) was placed in contact with film at
room temperature. Test is performed after the dough was
proofed to twice its original size.

I'. Dough (no yeast) was placed in contact with film
surface. refrigerated for 4 hours, then was allowed to
reach room temperature before performing the test.

J'. Dough (no yeast) was placed in contact with film
surface. Test was performed after the dough was made.

86

Dough treatment had a definite impact on Wtforce
values. For all three flours, proofed-yeast dough had less
adhesion. Pastry flour doughes were less adhesive. With
pastry doughes, Teflon had better release properties. The
thass values also show better release for proofed-yeast
dough systems. Pastry doughes had less adhesion. Dough
release from Teflon was generally better than from PET and
LDPE. The temperatures used to age the dough did not result
in different adhesion strengths.

4.2.4 Wtforce/Itnass Results

The effect of flour type, yeast, temperature, and film
type on Wtforce and thass were studied. Analyses of
variance results for the Wtforce and thass values are given
in Table 13 and 14. All four factors had significant effect
on thass. All factors, except for temperature, had
significant effects on Wtforce.
l as

According to Tukey's Honestly Significant Difference
test results for yeast conditions, there was no significant
difference between contact-first-yeast and proof-first-yeast
dough mean values (Appendix C, Table 25). There was no
significant difference between Hi-protein and bread flour
mean values (Appendix C, Table 26). When considering the
flour factors, both were significantly different (p < 0.05)
from pastry flour. According to the test results, the

protein content may have an effect on the stickiness of the

87

Analysis of variance for Wtforce values of 3
different types of flours under three different
yeast conditions at various temperature on 3
different films

Table 13

Source of Degree of Sum of Mean F P
variation freedom squares Square values

Yeast (Y) 2 49930.570 24965.285 1587.6636 0.0000**
Flour (F) 2 38076.142 19038.071 1210.7233 0.0000**
YF 4 8661.255 2165.314 137.7028 0.0000**
Replic (YF) 45 3911.319 86.918 5.5276 0.0000**
Temp. (T) 1 51.229 51.229 3.2579 0.0778
YT 2 306.707 153.353 9.7525 0.0000**
FT 2 136.557 68.278 4.3422 0.0189*
YFT 4 177.790 44.448 2.8266 0.0356*
Error 45 707.604 15.725

Film (M) 2 9373.635 4686.818 203.4749 0.0000**
YM 4 886.085 221.521 9.6172 0.0000**
FM 4 562.259 140.565 6.1025 0.0001**
YFM 8 1065.557 133.195 5.7826 0.0000**
TM 2 2.586 1.293 0.0561

YTM 4 167.499 41.875 1.8180 0.1273
FTM 4 7.269 1.817 0.0789

YFTM 8 172.960 21.620 0.9386

Error 180 4146.100 23.034

Total 323

represent p < 0.05

** represent p < 0.01

88

Table 14 Analysis of variance for thass values of 3
different types of flours under three different
yeast conditions at various temperature on 3
different films

Source of Degree of Sum of Mean F Probability
variation freedom squares Square values

Yeast (Y) 2 5.787 2.894 352.2237 < 0.0000**
Flour (F) 2 1.493 0.747 90.8741 < 0.0000**
YF 4 2.124 0.531 64.6488 < 0.0000**
Replic (YF) 45 0.277 0.006 0.7489

Temp. (T) 1 0.084 0.084 10.2407 < 0.0025**
YT 2 0.057 0.029 3.4913 < 0.0389*
FT 2 0.031 0.016 1.9105 > 0.1598
YFT 4 0.013 0.003 0.3841

Error 45 0.370 0.008

Film (M) 2 3.889 1.944 350.4445 < 0.0000**
YM 4 1.479 0.370 66.6561 < 0.0000**
FM 4 0.660 0.165 29.7597 < 0.0000**
YFM 8 1.844 0.231 41.5487 < 0.0000**
TM 2 0.035 0.017 3.1331 < 0.0460*
YTM 4 0.047 0.012 2.1335 > 0.0785
FTM 4 0.012 0.003 0.5544

YFTM 8 0.039 0.005 0.8765

Error 180 0.999 0.006

Total 323

represent p < 0.05
represent p < 0.01

89
tested doughes. Noguchi (1976) suggested that dough
stickiness correlated highly with the sulfhydryl content of
the protein, but protein content itself did not correlate
with adhesiveness. Protein content largely determines the
grain's suitability for its intended end use.

Yeast exists and is active in air as well as in the
absence of air, but its behavior will change according to
the environment (Vallery-Radot, 1957). In the presence of
air, yeast grow rapidly and produce little alcohol, while in
the absence of air, yeast growth is slow but alcohol
formation is favored. During yeast fermentation, glycerol
and succinic acid will also be produced, as well as carbon
dioxide.

Yeast provides flavoring compounds, affects the texture
of dough and baked product, and creates carbon dioxide which
decreases the density of the food (Matz, 1960). Carbon
dioxide passes through the yeast cell wall as a dissolved
compound, probably in the form of a bicarbonate ion. As the
concentration of carbon dioxide increases in the free liquid
outside the cell, gas bubbles begin to form around foci in
the dough. The formation and migration of carbon dioxide in
a network of cellular compartments, occupy about 120 cubic
inches per pound of loaf, and serves to lighten or raise the
dough. The physical properties of the dough are altered
through the powerful stretching actions generated by

diffusion and accumulation of carbon dioxide throughout the

9O
dough mass.

The effect of yeast condition on thass depended on the
flour (F = 90.874, p = 0.000, Fig. 21). Pastry flour (with
yeast) had higher mean values than bread flour (with yeast),
perhaps because the cohesion forces within pastry flour is
lower than the adhesion forces to films, so the remaining
dough on the film will be higher. When there is no yeast in
the dough, bread flour is most sticky.

Tukey's Honestly Significant Difference Test result of
thass (Fig. 22, Appendix C, Table 27) showed that the
effect of yeast condition varied for different types of
flours. For thass measures, values were highest when
flours had no yeast. When flours had proof-first-yeast,
both values were second highest. And when flour had
contact-first-yeast, both values were the lowest. These
differences appeared stronger for Hi-protein and bread
flours.

There was a highly significant (p < 0.01) difference
between yeast condition and temperature for thass (F =
3.491, p = 0.0389) (Fig. 23). The effect of yeast condition
depended on the effect of temperature for thass values.
Mean values at refrigerated temperature were higher than
those at room temperature for contact-first-yeast and no-
yeast dough. Figure 23 shows that the proof-first-yeast
dough at room temperature had higher values than those at

refrigerated temperature. Tukey's Honestly Significant

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93
Difference test results of thass indicated that the effect
of yeast condition varied under different temperatures.
However, within each yeast condition the effect of
temperature was not significant (Fig. 24, Appendix C, Table
28).

The effect of flour type on thass (F = 3.491, p =
0.0389) depended on temperature (Fig 25). Tukey's Honestly
Significant Difference test results (Fig. 26, Appendix C,
Table 29) showed how the effect of temperature condition
varied for different types of flours. Higher values
occurred for the flour at refrigerated temperature. These
differences appeared stronger for Hi-protein and bread
flours. When the dough was put in the refrigerator, the
protein structure may have changed, and the low temperature
will slow down the yeast fermentation. These factors may
make the dough more sticky.

A three-way interaction of yeast, flour, and
temperature was not significant for thass. This three-way
interaction is illustrated in Figures 27 and 28. Figure 27
shows that at room temperature, bread flour with no-yeast
dough had the highest mean value, and pastry flour with
contact-first-yeast dough had the lowest mean value.

Figure 28 shows that bread flour with no-yeast dough
had the highest mean value, and pastry flour with contact-
first-yeast dough had the lowest mean value. For both room

and refrigerated temperature, bread flour with proof-first—

 

  

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96

yeast was lower than contact-first-yeast dough. The mean
value of pastry flour at room temperature was higher than
flours at refrigerated temperature. The same situation
occurred with Hi-protein and bread flour with proof-first-
yeast dough. The Tukey's Honestly Significant Difference
test results of thass values are listed in Appendix C,
Table 30.

The effect of film type on thass (F = 350.445, p
=0.0000) was highly significant among all films. Tukey's
Honestly Significant Difference test indicated that there
was no significant difference between PE and PET film, but
both films were significantly different (p < 0.05) from
Teflon film (Appendix C, Table 31). This may be due to
Teflon film's superior anti-stick/low friction properties
(Dupont, 1988).

The effect of yeast condition on thass varied for the
different films (F = 350.445, p = 0.0000). The mean values
of Teflon film were the lowest of all (Fig. 29). For both
proof-first-yeast and contact-first-yeast dough, the mean
values of PET film were higher than those of the PE films,
but for no-yeast dough, the mean value of the PE film was
higher than PET film. Tukey's Honestly Significant
Difference test indicated that there was no significant
difference between PE and PET film for proof-first—yeast and
contact-first-yeast dough (Fig. 30, Appendix C, Table 32).

For no-yeast dough, there was a significant difference

97

 

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98
between PE and PET film. PE film was slightly less sticky
than PET film with yeast dough, however, with no-yeast, PE
film was much more stickier than PET film.

The interaction between flour and film was highly
significant on thass (F = 29.760, p = 0.0000). The Teflon
film had the lowest mean values of all. The mean value for
the PET film was higher than the PE film (Fig. 31), and the
mean value of PE film with bread flour was the highest.
Tukey's Honestly Significant Difference test results of
thass (Fig. 32, Appendix C, Table 33) indicates that there
was no significant difference between Hi-protein and bread
flour with PE or PET film, and no significant difference
between Hi-protein and bread flour with Teflon film. There
was no significant difference between PE and PET with the
pastry flour.

A three-way interaction of yeast, flour, and film was
highly significant for thass (F = 41.549, p = 0.0000).
This three-way interaction is illustrated in Figures 33, 34,
and 35. Stickiness depended on yeast condition, flour, and
type of film.

Figure 33 shows that the mean values of proof-first-
yeast dough on PET film were higher than those of PE and
Teflon film for all three flours. Figure 34 shows that the
mean value of contact—first—yeast on PET film was higher
than those of PE film with bread and pastry flours, but with

Hi-protein flour, the mean value of PE film was higher than

 

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102
PET film. Teflon film with pastry flour had the lowest mean
value of all. Figure 35 shows that for all three flours,
the mean values of PE film were higher than the mean values
of PET film. These differences appeared stronger for bread
flour. Tukey's Honestly Significant Difference test results
of thass values are listed in Appendix C, Table 34.

The interaction between temperature and film type was
significant (F = 3.133, p = 0.0460) for thass (Fig. 36).
Under refrigerated temperature, thass values were higher
than those at room temperature. Tukey's Honestly
Significant Difference test indicated that Teflon film was
less sticky than both PE and PET film. Temperature had no
effect on all three films for thass (Fig. 37, Appendix C,
Table 35).

The flour samples used were Hi-protein, bread, and
pastry flour. According to the manufacturing company
(General Mill, Inc., 1991), Hi-protein flour was milled from
a hard spring wheat, bread flour was milled from hard winter
wheat, and pastry flour was milled from hard and soft winter
wheat blend.

Hard wheat is physically hard, and has relatively high
protein content. The hardness is under genetic control and
is thought to result from the strength of the bonding
between the protein and starch in the endosperm (Hoseney,
1978). Bonding between protein and starch is weak for soft

wheat. Soft wheat is low in protein. Also, dough from a

 

 

 

 

 

 

 

 

 

Home 37. Tukey's HSD test Wtrnass mean values at room and refrigerated
tempetature dough wIth PE. PET. and TEFLON flm.

104

high protein flour will have less mobility or greater
stiffness than from a low protein flour with the same
percentage of absorption. This may explain why the
different types of flour react differently.
ntgoroe

According to Tukey's Honestly Significant Difference
test results, there was no significant difference between
proof-first-yeast and no-yeast dough for Wtforce values
(Appendix C, Table 36). There was a significant difference
(p < 0.05) between Hi-protein, bread, and pastry flour for
Wtforce values (Appendix C, Table 37).

The effect of yeast condition depended on the flour
type for Wtforce (F = 137.703, p = 0.000, Fig. 38).
Contact-first-yeast dough had lower Wtforce mean values than
proof-first-yeast dough. Pastry flour had the lowest mean
values among all flours, bread flour was most sticky.

Tukey's Honestly Significant Difference Test result of
Wtforce (Fig. 39, Appendix C, Table 38) showed that the
effect of yeast condition varied for different type flours.
Values were highest when flours had no yeast. When flours
had proof-first-yeast, both measures (thass and Wtforce)
were second highest. And when flour had contact-first-
yeast, both measures had the lowest values. These
differences appeared stronger for Hi-protein and bread
flours.

All gluten proteins contain disulfide groups, each

 

 

 

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Home 39. Tukey's HSD test Wtforce mean values of HI-protein. breed and pastry
_ flour with prod-first. contact-first, and no-yeeet dough.

106

polypeptide chain has an average of two (Wall, 1967).
Although gliadin and glutenin proteins possess similar amino
acids, their physical behaviors differ; hydrated gliadin is
a viscous mass, whereas hydrated glutenin is cohesive and
elastic. In the hydration stage during dough formation,
water penetrates the protein particles and associated with
polar sites, overcomes forces that cause the molecules to
adhere. Some of the protein molecules may be cleaved at the
disulfide bonds and reassembled by oxidation to conform more
effectively to the mixing stress. During proofing, the
protein matrix is stretched. The ability to stretch depends
upon the elastic characteristics of the gluten protein.

Yeast brings about changes in the dough in the course
of fermentation. This includes depletion of fermentable
substances, accumulation of waste products in the form of
carbon dioxide, alcohols, acids and esters, modification of
pH conditions, and a softening or mellowing of the gluten
character (Pyler, 1978). According to Jackel (1969), yeast
requires about 45 min in a favorable environment to attain
full adaptation to fermentation. Proteolytic enzymes act
upon the protein materials of the dough, the overall effect
of these enzymatic reactions is a softening of the dough,
due in part to a reduction in the absorption capacity of the

starch material, and in part to a weakening of the gluten

system.

There was a highly significant (p < 0.01) difference

107
between yeast condition and temperature for Wtforce (F =
9.753, p = 0.0003, Fig. 40). The effect of yeast condition
depended on the effect of temperature for Wtforce values.
Mean values at refrigerated temperature were higher than
those at room temperature for contact-first-yeast dough.
Figure 40 shows that the mean values of proof-first-yeast
dough at room temperature were higher than those at
refrigerated temperature. No-yeast dough showed higher
values at room temperature than at refrigerated temperature.

Tukey's Honestly Significant Difference test results of
Wtforce indicated that the effect of yeast condition varied
under different temperatures. However, within each yeast
condition the effect of temperature was not significant (Fig
41, Appendix C, Table 39).

The effect of flour on Wtforce (F = 4.342, p = 0.0189)
depended on temperature (Fig 42, 43, Appendix C, Table 40).
Higher Wtforce mean values occurred for flour at
refrigerated temperature. These differences appeared
stronger for Hi-protein and bread flours.

A three-way interaction of yeast, flour, and
temperature was significantly different (F = 3.491, p =
0.0356) for Wtforce. This three-way interaction is
illustrated in Figure 44, 45, and Appendix C Table 41.
Figure 44 shows that at room temperature, pastry flour with

contact-first-yeast dough had the lowest mean value. Except

for bread and pastry flour with proof-first-yeast and no-

 

- noon TE n. m'C)
nsrm. 're p

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dmnhetroomammedtempemure

     

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41. Tukey's HSD test Wtfowe mean values of proof-first, contact-first
and no-yeeet dough at room and remgenmd temperature.

 

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\

I'll-PROTEIN F R ER

   

FIgure42. TheWfloree ueeoIHI-ptueh.breed.andpeeuynwrdwgh
almanaMreflIgeratedtempetmne.

 

 

 

 

 

 

 

 

Home 43. Tukey’s HSD test Wtforce mean values of HI-proteIn. breed. and
paetryflouret roomand reI‘rIgerated temperature.

110
yeast dough, the Wtforce values at refrigerated temperature
were higher than those at room temperature.

The effect of film type on Wtforce (F = 203.475, p =
0.0000) was highly significant among all films. Tukey's
Honestly Significant Difference test indicated that there
was no significant difference between PE and PET film, but
both films were significantly different (p < 0.05) from
Teflon film (Appendix C, Table 42).

The effect of yeast varied for the different films for
Wtforce (F = 203.475, p = 0.0000, Fig. 46). The mean values
for the Teflon film were the lowest of all. For the
contact-first-yeast, the mean value of the PET film was
higher than that of the PE film.

Tukey's Honestly Significant Difference test indicated
that there was no significant difference between PE and PET
film for proof-first-yeast and contact-first-yeast dough
(Fig. 47, Appendix C, Table 43). For no-yeast dough, there
was no significant difference between PE and PET film. PE
film was slightly less sticky than PET film with yeast
dough, however, with no-yeast, PE film was much more sticky
than PET film.

The interaction between flour and film was highly
significant on Wtforce (F = 9.617, p = 0.0000). The Teflon
film had the lowest mean values of all. For both Hi-protein
and bread flour, the mean values of PE and PET film were

close (Fig. 48), while the mean value of Teflon was lower.

 

arr-tone: (cu/cu-sg)
3 3 ‘8 3 8 3 3

 

 

 

FIgureu. TheMorceveIueedHI-proteh. breed,endpeetlymmproof-fira.
corned-firstand no-yeeetdouohat room (23°C) temperature.

 

TRY LOUR

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5

55

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PROOF-F CONTACT-FIRST no vans?

//

 

 

    

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Floure45. TheWtforeevelueedHI-proteln.breed.andpaeu'yflwwmproot-flret,
- cornea-fire!“ no—yeaetdouohat relflgerated (4°C) temperature.

n \
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'10

 

 

 

CON TTAO-F IRST NO YEAST

Flore“. TheWtIoroeveIueeof prod-fitnoorwed-flMeMno-yeaetdough
onPE PET andTEFL .

 

 

 

 

WT-PORCI (GM/cn-eo)
0
o o 3 8 3 S 8
1w Al I l l
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FIgure47. Tukey'eH ‘SDt tEofeaWtforcemnveluee dprfiqd-flmwm first.
amino-yeast dPEoughon PET,andTEFL

113
Pastry flour - film interactions were the lowest.

Tukey's Honestly Significant Difference test results
(Fig. 49, Appendix C, Table 44) indicates that there were no
significant differences for Hi-protein and bread flour with
either PE or PET film, and no significant differences
between Hi-protein and bread flour for Teflon film. There
was no significant difference between PE and PET film for
pastry flour.

A three-way interaction of yeast, flour, and film was
highly significant for Wtforce (F = 5.783, p = 0.0000). This
three-way interaction is illustrated in Figure 50, 51, and
52. Stickiness depended on yeast condition, flour, and type
of film.

Figure 50 shows that the mean values of proof-first
yeast dough on PET film were higher than those of PE film
with Hi-protein and bread flours. Figure 51 shows that the
mean value of contact-first-yeast on PET film was higher
than those of PE film for all three flours. Teflon film
with pastry flour had the lowest Wtforce value of all.

Figure 52 (Appendix C, Table 45) shows that for no-
yeast dough the mean value of PE film with bread flour was
the highest, and the Teflon film with pastry flour the

lowest. For both Hi-protein and bread flour, the mean value

of PE film was higher than that of PET film. For pastry

flour, the mean value of PET film was higher than PE film.

The interaction between temperature and film on Wtforce

"4

 

   

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Home. TheVWoroevdueeolHI—proteh,breed.endpestryllwonPE.
PET.andTEFLONIIm.

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20 1
10 "
’ —~— PE -+— PET + TEFLON
0 r

HI—pfmdn

 

 

w-r-roncz (cu/cu-sg)
‘

 

 

 

Figure 49. Tukey's HSD test Wtforce meen values 0! Hl-proteln. breed. and
pastry Ilour on PE. PET, and TEFLON Ilrn.

"5

 

   
  

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FIgure50.1110thoroevdueolHI—pr0teh.hreed.andpestryfiouonPE.
PET. and TEFLON llm wlth prud-fiet—yeeet dough.

 

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.e d R? R3

 

 

 

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I'll-PROTEIN FLOUR BREAD FLOUR PASTRY FLOUR

FI9ure51. TheWtIoroevelueotHI-proteln. breed.and pastryllouron PE,
PET. and TEFLON flm wlth contact-first-yeaet dough.

 

 

 

 

 

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“mm

Marco vuue of HI—proteln. breed. and pastry flour on PE, PET, and TEFLON

117
was not significant (Fig. 53). For doughes at refrigerated
temperature, mean values were higher than those at room
temperature. Tukey's Honestly Significant Difference test
indicated that Teflon film was less sticky than both PE and
PET film. Temperature had no effect on any of the three
films (Fig. 54, Appendix C, Table 46).

In the original study, we reported force per unit area
at separation which implies that force is proportional to
the contact area between the film and the dough. In a
separate study, this hypothesis was tested by incorporating
various lengths and widths of the film. Doubling the width
of the film and leaving the same length increased the force
by 1.75 times instead of two times as expected. Doubling
the length of the film and leaving the same width only
increased the force 1.2 times instead of two times as
expected. Therefore, force is not proportional to area, nor
is it proportional to length or width of the film.
Therefore, in future studies, only the force of a given

standardized opening should be reported.

 

 

 

 

 

 

 

 

 

 

CONCLUSIONS

This study was designed to:
1. Evaluate a device for determining adhesion between
refrigerated dough and the contacting surface, and
2. To determine the influence of flour type, yeast
condition, and temperature on adhesion between
dough and plastic films.
The major findings of the study are summarized below:
(1) Phase I Study:
Wettability Test
A. Wettability was characterized using the inclined plane
method, and the results show that PETG had the highest angle
and Teflon had the lowest angle.
Stickiforce Meter Test
B. Proof-first-yeast dough on PETG film at 4°C had the
highest thass mean value, and contact-first-yeast dough on
Teflon film at 23°C had the lowest thass mean value. As
for the Wtforce mean values, proof-first-yeast dough on film
78698 at 4°C had the highest mean value, and contact-first-

yeast dough on Teflon film at 4°C had the lowest.

thass

PETG was found to be the most adhesive material, and

119

120

Tri-extruded PE found to be the least adhesive material.
When we consider both film and yeast factors, PETG with
proof-first-yeast dough remained the most adhesive
interaction, and HDPE with contact-first-yeast dough was
found to be the least adhesive. Considering various films
and the different temperatures, PETG at 4°C proved to be the
most adhesive, and Teflon at 23°C was found to be the least.
With all three factors combined, PETG with proof-first-yeast
dough at 4°C was found to be the most adhesive material, and
Teflon with contact-first-yeast dough at 23°C was found to
be the least adhesive.

Wtforge

The Wtforce values of Silicone release paper are a
result of that material requiring the highest amount of
water to break away the test film from the dough surface.
Teflon film used the least amount of water. When type of
film and the yeast factor are considered, film 78G98 with
proof-first-yeast dough was found to be the material that
required the greatest force, and Teflon film the least. If
we combine film type with the temperature factor, Silicone
release paper at 4°C required the most force and Teflon at
4°C required the least. When we combine all three factors
together, film 78098 with proof-first-yeast dough at 4°C was
found to be the material that used the highest amount of
water to break the test film away from the dough surface,

0 O
and the Teflon film with contact-flrst-yeast dough at 4 C

121
used least amount of water. Each factor contributed to and
affected the dough stickiness.
1W:
Wettability Test
A. The results from performing the Inclined plane method
show that PET had the highest angle, and Teflon had the
lowest angle.
stickiforce Meter Test

B. Bread flour with no-yeast dough on PE film at 4°C had
the highest thass mean value, and pastry flour with no-
yeast dough on Teflon film at 23°C had the lowest thass
mean value. As for the Wtforce mean values, bread flour
with no-yeast dough on PE film at 23°C had the highest mean
value, and pastry flour with contact-first-yeast dough on
Teflon film at 4°C had the lowest.

thasg

PE film found to be the most adhesive material, and
Teflon film found to be the least adhesive material. Bread
flour had the highest adhesive property, and pastry flour
had the lowest. When yeast conditions are combined with the
flour factor, bread flour with no-yeast dough had the
highest adhesiveness, and pastry flour with contact-first-
yeast dough had the lowest. Considering yeast conditions,
flour factor and temperature factor together, bread flour
with no-yeast dough at 4°C had the highest adhesiveness, and

pastry flour with contact-first-yeast dough at 23°C had the

122
lowest. Combine the four factors (Yeast, flour,
temperature, and film) together, bread flour with no-yeast
dough at 4°C on PE film was the most adhesive, and pastry
flour with contact-first-yeast dough on Teflon film at 4°C

was the least adhesive.

litters;

The Wtforce mean values showed that PE film was the
material that used the most force to break the test film
away from the dough surface and Teflon film the least.
Considering both film and yeast factors, PE film with no-
yeast dough used the highest amount of water to break away
from the film, and Teflon film with contact-first-yeast
dough the least. When film type and flour factors are
considered, Hi-protein flour with PE film required the most
force, and pastry flour with Teflon film required the
lowest. Considering film type with yeast and flour factors,
bread flour with no-yeast dough on PE film required the
highest amount of water, and pastry flour with contact-
first-yeast dough on Teflon film the least. Looking at the
mean values of film types, and both flour and temperature
factors, Hi-protein flour on PE film at 4°C found was the
highest, and pastry flour on Teflon film at 23°C the lowest.
Combining all factors, bread flour with no-yeast dough on PE
film at 23°C was the combination that used the highest
amount of water to break the test film away from the dough

surface, and pastry flour with contact-first-yeast dough on

123
Teflon at 4°C was the combination that used the least.
(3) PVC, PET, and PETG all have a polar surface. That may
be one reason why these three films stuck to the dough more
than the other materials. The use of release agents, added
as resins or used as coatings applied to a solid, may
prevent/decrease adhesion of another solid. Hwoever, the
silicone-based materials did not provide the required
release properties. This was true in all cases.
(4) Good correlation was observed between the Wtforce
(gram-force) and thass (gram-mass) results. R3 = 0.80 for
Phase I study, and R2 = 0.92 for Phase II study.
(5) Yeast provides flavoring compounds, affects the texture
of dough, and creates carbon dioxide. The physical
properties of the dough are altered through the powerful
stretching actions generated by diffusion and accumulation
of carbon dioxide throughout the dough mass, and the web
structure reveals that thin-walled gluten strands offer
minimum resistance to stretching when pulled. This might
explain why yeast dough was less sticky than no-yeast dough.
(6) Hard wheat has relatively high protein content.
Greater stickiness of this type of dough is thought to
result from the strength of the bonding between the protein
and starch in the endosperm. The high protein dough has
less mobility and greater stiffness. Bonding between
protein and starch is weak for soft wheat, which usually is

low in protein content. This may explain why different

124
types of flour reacted differently in the tests performed.
(7) The original hypothesis that the force is required for
separation is proportional to the contact area between the
film and the dough was proven false by testing various
lengths and widths of film. Doubling the width and length
of the film increases the force by only 1.75 and 1.2 times

respectively, rather than the expected 2 times.

RECOMMENDATIONS

The instrumental technique using a Stickiforce Meter
appears useful for measuring dough stickiness. The
following are recommendations for future research:

1. The testing results obtained from a Farinograph will
differ if test factors are strictly controlled. The
variation of dough development will change the mixing
tolerance index. Normally, relative humidity and
temperature are controlled factors when using a Farinograph.
When the experiment environment changes, the instrument
changes, and results will vary considerably if there is no
viable control.

2. Standardize the test conditions to obtain meaningful
comparisons, which requires selection and control of
temperature, relative humidity, and fermentation time.

3. The use of commercial flour instead of the pure variety
did not enable us to differentiate what kind of protein and
starch are in the flour. We need to do more chemical
compound testing to obtain the ingredient analysis of each
flour type: That is, the percentage of each component of
protein and starch, in order to do a more comprehensive

study on the cause of stickiness in dough.

125

APPENDICES

APPENDIX A

126
APPENDIX A

Absorption at 14% moisture content
BtM

 

A-86 100-M_14
Pastry Bread Hi-protein
Flour Flour Flour
M : Flour Moisture 9.38% 9.27% 9.08%
A : Absorption 14% mb
B : Absorption, as-is mb
Héo Added 29.52 ml 32.65 ml 33.20 ml
Flour Weight 50.48 g 47.50 g 46.80 g

Pastry Flour

._100x29.52_58'48%

B 50.48

58.48.~9.38_14_50_4

A'86x loo-9.38

Bread‘Flour

_100x32.5_68.4%

B 47.5

58'4+9'27-14-59.62

A'86x'100-9.27

Hi-protein Flour

_100x33.2_70.94%

B 46.8

70.94+9 '08-14-61.69

A'sax 100-9.08

APPENDIX B

127
Appendix B

Tukey's Honestly Significant Difference Test of
Wtforce and thass Results for Phase I Study

Table 15. thass mean values of the test materials.

 

Film Type Mean1
PETG 4.7 x 10'2“
ISC-60 3.5 x 10'2a
78098 2.8 x 10-2a
pvc 2.8 x 10‘2‘1
SILICONE PAPER 2.4 x 10‘2“
HDPE 1.9 x 10'2“
PET 1.2 x 10'2“
80C146A 6.6 x 10‘3“
2% EVA/VEG OIL 3.3 x 10'3“
KRAYTON 1.2 x 10’ a
2% EVA/MYV 9-40 8.2 x 10::
2% EVA/1.5% PAM 7.5 x 104‘
TEFLON FEP 7.2 x 104‘
TRI-EXTRUDED PE 6.7 x 10

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

128

Table 16. thass mean values of the test materials with
proof-first and contact-first yeast dough.

Treatment Mean
PETG/Proof-first 9.2 x 10'2“-1
ISC-60/Proof—first 6.4 x 10'2“
PVC/Proof-first 5.2 x 10‘2a
SILICONE/Proof—first 4.4 x 10'2“
78698/Proof—first 4.3 x 10'“
HDPE/Proof-first 3.7 x 10'2“
PET/Proof-first 2.3 x 10‘2“
78698/Contact-first 1.4 x 10‘2‘3
80C146A/Proof-first 8.5 x 10'3“
EVA/OIL//Proof-first 5.8 x 10'3‘51
ISC-60/Contact-first 5.3 x 10'3“
80C146/Contact-first 4.6 x 10'3‘a
PVC/Contact-first 3.9 x 10'3‘a
SILICONE/Contact-first 3.7 x 10:3“
KRAYTON/Proof-first 1.5 x 10_3a
PETG/Contact-first 1.4 x 10_3a
PET/Contact-first 1.3 x 10_3a
EVA/PAM/Proof—first 1.1 x 104:
EVA/MYV/Proof-first 9.9 x 10-48
TEFLON/Proof-first 9.5 x 104”l
KRAYTON/Contact-first 9.3 x 10_4a
EVA/OIL/Contact-first 7.4 x 10__4a
TRI/PE/lProof-first 7.1 x 10_4a
EVA/MYV/Contact-first 6.5 x 10_¢a
TRI/PE/Contact-first 6.3 x 10%a
TEFLON/Contact-first 5.0 x 10_4a
EVA/PAM/Contact-first 4.5 x 10_4a
HDPE/Contact-first 4.0 x 10 -----
1 means followed by the same letters are not significantly

different at p < 0.05 by Tukey's HSD Test

129

Table 17. thass mean values of the test materials at
room (23°C) and refrigerated (4°C) temperature.

Treatment Mean
PETG/Refri 9.2 x 10'2“
ISC-GO/Refri 6.5 x 10'1“"l
PVC/Refri 5.5 x 10'1’‘3
78698/Refri 5.1 x 10‘2“
SILICONE/Refri 4.5 x 10'2“
HDPE/Refri 3.6 x 10"2a
PET/Refri 2.3 x 10‘2“
80C146A/Refri 1.1 x 10'2a
EVA/OIL/Refri 6.2 x 10'3“
78G98/Room 5.2 x 10'3:!
ISC-60/Room 3.8 x 10'3“
SILICONE/Room 2.8 x 10'?3‘
80C146A/Room 2.5 x 10:3a
KRAYTONE/Refri 1.7 x 10_3ll
EVA/MYV/Refri 1.3 x 10_3a
TEFLON/Refri 1.2 x 10 33
PET/Room 1.1 x 10:3‘a
HDPE/Room 1.0 x 10_3:
PETG/Room 1.0 x 10_¢a
EVA/PAM/Refri 9.2 x 10%a
TRI/PE/Refri 8.7 x 10_4a
PVC/Room. 7.8 x 10_4a
KRAYTON/Room 7.0 x 10_¢a
EVA/PAM/Room 5.8 x 10-4a
TRI/PE/Room 4.6 x 10_¢a
EVA/OIL/Room 4.2 x 104‘a
EVA/MYV/Room 3.5 x 1043
TEFLON/Room 2-5 X 10

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

"WLL "

M

130
Table 18. thass mean values of proof-first and contact-

first yeast dough at room (23°C) and refrigerated
(4°C) temperature.

Treatment Mean1
Proof/Refri 5.2 x 10'2“
Contact/Refri 4.3 x 10‘2‘
Proof/Room 2.9 x 10‘:3
Contact/Room 1.1 x 10"'1

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

 

 

131

Table 19. thass mean values of the test materials with
proof-first and contact-first yeast dough at
room (23°C) and refrigerated (4°C) temperature.

PETG/Proof-first/Refri
ISC-60/Proof-first/Refri
PVC/Proof-first/Refri
SILICONE/Proof-first/Refri
78G98/Proof—first/Refri
HDPE/Proof-first/Refri
PET/Proof-first/Refri
78698/Contact-first/Refri
80C146A/Proof-first/Refri
EVA/OIL/Proof-first/Refri
ISC-60/Contact-first/Refri
PVC/Contact-first/Refri
78698/Proof-first/Room
80C146A/Contact-first/Refri
ISC-60/Proof-first/Room
SILICONE/Contact-first/Refri
SILICONE/Proof-first/Room
78698/Contact-first/Room
ISO-60/Contact-first/Room
80C146A/Contact-first/Room
80C146A/Proof-first/Room
KRAYTON/Proof-first/Refri
SILICONE/Contact-first/Room
PETG/Contact-first/Refri
PET/Contact-first/Refri
TEFLON/Proof-first/Refr
HDPE/Proof-first/Room
EVA/MYV]Proof-first/Refri
KRAYTON/Contact-first/Refri
EVA/OIL/Contact-first/Refri
EVA/PAM/Proof-first/Refri
PET/Proof-first/Room .
EVA/MYV/Contact-first/Refr1
PETG/Contact-first/Room
PET/Contact-first/Room
EVA/PVM/Proof-first/Room
PVC/Proof-first/Room .
TRI/PE/Proof—first/Refri
PETG/Proof—first/Room
KRAYTON/Proof—first/Room
TRI/PE/Contact-first/Refri
TEFLON/Contact-first/Refri.
EVA/PAM]Contact-first/Refri
PVC/Contact-first/Room

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132
Table 19: (cont'd)

Treatment Mean1
EVA/OIL/Proof-first/Room 5.7 x 10"“3
KRAYTON/Contact-first/Room 5.6 x 10'“°
HDPE/Contact-first/Room 5.0 x 10'“°
TRI/PE/Proof-first/Room 5.0 x 10”“’
EVA/MYV/Proof-first/Room 4.8 x 10"413
TRI/PE/Contact-first/Room 4.3 x 10'413
TEFLON/Proof—first/Room 3.3 x 10‘“’
HDPE/Contact-first/Refri 3.1 x 10‘“’
EVA/OIL]Contact-first/Room 2.6 x 10"“3
EVA/MYV/Contact-first/Refri 2.2 x 107“”
EVA/PAM/Contact-first/Room 2.1 x 10'"413
TEFLON/Contact-first/Room 1.7 x 10'413

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 20. Wtforce mean values of the test materials.

Film Type Mean

_ _______________________________________________ ;__
SILICONE PAPER 18.19a
78G98 16.27ab
Isc-eo 14.20am
80C146A 12 . 805cc
PETG 10.22b d
PET 8.86 c e
pvc 8.40%“?
HDPE 7.09;;
2% EVA/VEG OIL 6.28def
KRAYTON 131-22“
2% EVA/1.5% PAM 3.359f
TRI-EXTRUDED PE 3'04“
2% EVA/MYV 9-60 2-75f

TEFLON FEP

1 means followed by the same letters are no
different at p < 0.05 by Tukey's HSD Test

t significantly

at

133

Table 21. Wtforce mean values of the test materials with
proof-first and contact-first yeast dough.

Treatment Mean
78698/Proof-first 20.80a
SILICONE /Proof-first 19 . 62*511D
ISC-60/Proof-first 18 . 03"”
SILICONE [Contact-first 16 . 75abcd
PETG/Proof-first 15 . 92‘1”“
80C146A/Proof-first 13 . “bed“
PET/Proof-first 12 . 43¢def
PVC/Proof-first 12 . 3 6"def
80C146A/Contact-first 12 . 16Cdef
78698 [Contact-first 11 . 73°d°f9
ISO—60 / Contact-f irst 10 . 3 Gdefgh
HDPE/Proof—first 9 . 33°f‘3hi
EVA/OIL/Proof-first 7 . 64‘3”
KRAYTON/Proof-first 5 . 4 39hij
PET/Contact-first 5.29;j
EVA/OIL/Contact-first 4 . 91hij
HDPE/Contact-first 4.86Mj
PETG/Contact-first 4.52hig
PVC/Contact-first 4.44hij
EVA/PAM/Proof-first 4'321j
KRAYTON/Contact-first 3.64ij
EVA/MYV/Proof—first 3°601j
TRI/PE/Proof—first 3.59ij
EVA/PAM/Contact-first 3.40ij
TEFLON/Proof-first 3.16ij
TRI/PE/Contact-first 3.12j
EVA/MYV/Contact-first 2.48j
TEFLON/Contact-first 2.34

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 22. Wtforce mean values of the test material at
room (23°C) and refrigerated (4°C) temperature.

SLICONE/Refri
78698/Refri
ISC-GO/Refri
80C146A/Refri
PETG/Refri
PVC/Refri
PET/Refri
SILICONE/Room
78698/Room
HDPE/Refri
ISC-60/Room
EVA/OIL/Refri
80C146A/Room
KRAYTON/Refri
PETG/Room
PET/Room
EVA/PAM/Refri
PVC/Room
TRI/PE/Refri
KRAYTON/Room
EVA/PAM/Room
HDPE/Room
EVA/OIL/Room
EVA/MYV/Refri
TRI/PE/Room
TEFLON/Room
EVA/MYV/Room

10.79d9f9 E.
10 . 19d“?h '
9 . 169fghi
9 . ()ngth
5.48f9hi

5.35ghi
4.96ghi
4.23ghi
3.86hi
3.67hi
3.591
3.501
3.401
3.391
3.261
3.041
2.921
2.821
2.591

1 means followed by the same letters are not significantly

different at p < 0.05 by Tukey's HSD Test

135
Table 23. Wtforce mean values of proof-first and contact-

first yeast dough at room (23°C) and refrigerated
(4°C) temperature.

Treatment Mean1
Proof/Refri 14.99a
Contact/Refri 7.75”
Proof/Room 6.39”
Contact/Room 5.11”

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

n- P‘I-I
I

136
Table 24. Wtforce mean values of the test materials with

proof-first and contact-first yeast dough at
room (23°C) and refrigerated (4°C) temperature.

Treatment Mean
78698/Proof—first/Refri 28.19a
PETG/Proof-first/Refri 25.89“”
SILICONE /Proof-f irst/Refri 24 . 99”
ISC-60/Proof-first/Refri 23 . 89"”:d
SILICONE / Contact-f irst / Refri 22 . 83:”d
PVC/Proof-first/Refri 21.211) 2’ :
PET/Proof-first/Refri 19.13 S :
80C146A/Proof-first/Refri 16.60: i 9
80C146A/Contact-first/Refri 16.44 i :
HDPE/Proof-first/Refri 15 . 0729111
SILICONE/Proof-first/Room 14.25: :13
78698/Proof-first/Room 13 . 42159hijk
78698/Contact-first/Refri. i: - ggfghijk
ISC-60/Contact—f1rst/Refr1 1218fghijkl

ISC-60/Proof-first/Room .
EVA/OIL/Proof-first/Refr1
SILICONE]Contact-first/Room

10 .68ghijklmn

78698/Contact-first/Room
80C146A/Proof-first/Room

10. soghijklmno
8 ozohijklmnopq

lSC-60 / Contact- -f irst/ Room ° hij klmopq
80C14 6A/ Contact- -f 1rst / Room 7 . 89ijklmnopq
ICRAYTON/ Proof-f1rst/Refr1 7 . lSjklmnopq
EVA/OIL/Contact-f1rst/Refr1 6 . 84jklmnopq
HDPE/ Contact-f1rst/Refr1 6 . Sljklmnopq
PET / Contact- -f 1rst / Ref r1 6 . 4 oklmnopq
PETG / Proof— -f irst / Room 5 . 94km“)pq
PET/ Proof- f1rst / Room 5 . 741111;:qu
EVA/PAM/Proof- -first/Refri 5. 04mnopq
PETG / Contact-f irst / Room 4 . 7 6mopq
PVC / Contact-f 1rst / Refri 4 . 68mnopq
PETG] Contact-f irst / Ref r1 4 ' 2 ”man
PVC / Contact-f first / Room 4 ° 2 (1),”,qu
EVA/MYV/Proof- -first/Refri 2 ismopq
PET / Contact-f irst / Room 4 ° 0 znopq
TRI/PE/Proof— -first/Refri 3 ' 81mm
EVA / OIL/ Proof -f irst / Room 3 ' 8 0’1qu
KRAYTON/ Contact-f1rst/Refr1 3 ° 70mm
KRAYTON/ Proof— -f irst / Room 3 ° 6 0”qu
EVA/PAM/Proof-first/Room 3 ° 59mm
HDPE/ Proof— -f irst/ Room 3 ° 5 1mm
PVC / Proof —f irst / Room 3 ' 48mm
KRAYTON/ Contact-f irst / Room 3 ' 4 2mm
EVA/ PAM/ Contact-f1rst/Refr1 3 39mm

EVA/ PAM/ Contact-f irst / Room

137

Table 24: (Cont'd)

TRI[PE/Contact-first/Refri
TEFLON/Proof-first/Room
HDPE/Contact-first/Room
TRI/PE/Proof-first/Room
TEFLON/Proof-first/Refri
EVA/MYV/Proof—first/Room
EVA/OIL/Contact-first/Room
TRI[PE/Contact-first/Room
EVA/MYV/Contact-first/Room
TEFLON]Contact-first/Room
EVA/MYV]Contact-first/Refri
TEFLON/Contact-first/Refri

1 means followed by the same letters are
different at p < 0.05 by Tukey's HSD Test

not significantly

 

APPENDIX C

138
APPENDIX C

Tukey's Honestly Significant Difference Test for
Wtforce and thass Results for Phase II Study

Table 25. thass mean values of proof-first, contact-
first, and no-yeast dough.

 

1
_Yeast Type ___________________________ Mean ____________ 3
None 4 . 3 x 10': ;
Proof-first 1.8 x 10_n3
Contact-first 1.3 x 10 n

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 26. thass mean values of Hi-protein, bread, and
pastry flour.

Flour Type -EEEE .......
--------------------------------------------- -1a
. 2.9 x 10
H1-protein 1 5 x 10-11,
Pastry '

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

139

Table 27. thass mean values of proof-first, contact-first,
and no-yeast dough with Hi-protein, bread, and

pastry flour.

Treatment Mean1

None/Bread 6.3 x 10‘1‘El
None/Hiprotein 4.6 x 10'“’
Proof/Hiprotein 2.5 x 10’“:
None/Pastry 2.1 x 10'“:
Proof/Pastry 1.8 x 10"led
Contact/Hiprotein 1.8 x 10'lcd
Contact/Bread 1.4 x 10’1”:
Proof/Bread 1.2 X 10:23
Contact/Pastry 6.5 x 10

1 means followed by the same letters are not significantly

different at p < 0.05 by Tukey's HSD Test

Table 28. thass mean values of room (23°C)

and refrigerated

(4 ° C) temperature with proof -f irst , contact-f irst ,

and no-yeast dough.

Treatment Mean1 -------
None [Refri 4 . 5 x 10::
None/Room 4.1 x 10_n3
Proof-first/Room 1.9 x 10_n3
Proof-first/Refri 1.8 x 10_n)
Contact-first/Refri 1.6 x 10_2b

9.6 x 10

Contact-first/Room

1 means followed by the same letter are n
different at p < 0.05 by Tukey's HSD Test

at significantly

__13

140
Table 29. thass mean values of room (23°C) and refrigerated

(4°C) temperature with Hi-protein, bread, and
pastry flour.

Treatment Mean
Bread/Refri 3.2 x 10’1“
Hiprotein/Refri 3.1 x 10'1“
Hiprotein/Room 2.7 x 10’1“”
Bread/Room 2.7 x 10'1“”
Pastry/Refri 1.8 x 10'1b
Pastry/Room 1.5 x 10'1”

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 30. thass mean values of proof-first, contact-
first, and no-yeast dough with Hi-protein,
bread, and pastry flour at room (23°C) and
refrigerated (4°C) temperature.

Treatment Mean
Bread/None/Refri 6.6 x 103:1,
Bread/None/Room 6.0 x 10_1bc
Hiprotein/None/Refri 4.9 x 10_n:
Hiprotein/None/Room 4.3 x 10_1d
Hiprotein/Proof/Refri 2.5 x 10_1de
Hiprotein/Proof/Room 2.4 x lo—ldef
Pastry/None/Refri 2.2 x 10-1defg
Pastry/None/Room 2.1 x -1de f9
Hiprotein/Contact/Refri 2.0 x -1defg
Bread/Contact/Refri 1.9 x 10_1defg
Pastry/Proof/Room 1.8 x _ 1defg
Pastry/Proof/Refri 1.7 x 10_mefg
Hiprotein/Contact/Room 1.5 x 10_1defg
Bread/Proof/Room 1.3 x -1defg
Bread/Proof/Refri 1.2 x -2efg
Bread/Contact/Room 8.8 x 10_zfg
Pastry/Contact/Refri 7.7 x 10__29
Pastry/Contact/Room 5.3 x 10 ___________

1 means followed by
different at p < 0.05 by Tukey's HSD Test

Fr“ I‘m—4m

141

Table 31. thass mean values of PE, PET, and TEFLON film.

Film Type Mean1
p15: 3.5 x 10'1“
PET 3.0 x 10'1“
TEFLON 9.5 x 10'”
1 means followed by the same letter are not significantly [

different at p < 0.05 by Tukey's HSD Test i

-1'1'

Table 32. thass mean values of proof-first, contact-
first, and no-yeast dough on PE, PET, and TEFLON

film.

Treatment Mean1
None/PE 6.6 X 10:55
None/PET 4.1 x 10_11m
Proof-first/PET 3.1 x lo-lcd
None/TEFLON 2.3 x 10_led
Proof-first/PE 2.2 x 10_1cd
Contact-first/PET 1.9 x 104‘:le
Contact-first/PE 1.6 x 10_26
Contact-first/TEFLON 3.0 x 10_2e
Proof-first/TEFLON 2-5 x 1°

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

142

Table 33. thass mean values of Hi-protein, bread, and
pastry flour on PE, PET, and TEFLON film.

Treatment Mean
PE/Bread 4.8 x 10"la
PE/Hi-protein 4.0 x 10'1“”
PET/Hi-protien 3.5 x 10’11”
PET/Bread 3.0 x 10"1”c
PET/Pastry 2,5 x -1bc
PE/Pastry 2.0 x 10'1“1
TEFLON/Hi-protein 1.7 x 10'led
TEFLON/Bread 1.1 x 10'1“
TEFLON/Pastry 5.1 x 10'39

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 34. thass mean values of Hi-protein, bread, and
pastry flour with proof-first, contact-first and
no-yeast dough on PE, PET, and TEFLON film.

Treatment Mean
Bread / None [PE 1 . 1 x 103;,
Hiprotein/None/PE 5 . 0 x 10_1bc
Bread / None / PET 4 . 7 x 10_1bc
Hiprotein /None / PET 4 . 6 x 0_1bcd
Hiprotein / None / TEFLON 4 . 1 x 10_1bcde
Hiprotein/Proof/PET 3 . 7 x Gammaf
Pastry/None/PE 3 . 4 x lo—lcdef
Hiprotein/Proof/PE 3 . 2 x o-lcdefg
Pastry/Proof / PET 3 . 1 x -1cdefg
Pastry/ None / PET 3 . 0 x -lcdefgh
Bread / None /TEFLON 2 . 8 x 0_1defgh
Hiprotein [Contact / PE 2 . 5 x O-1defgh
Bread / Proof /PET 2 . 4 x —1efghi
Hiprotein /Contact / PET 2 . 2 x 0_ 18 fghi j
Pastry/Proof/PE 2 . 0 X _1efgh1j
Bread [Contact [PET 2 . 0 x _1 £9111 jk
Bread /Contact/PE 1 . 8 x -1ghijk1
Pastry/Contact/PT 1 . 5 x 10—1hijk1
Bread/Proof/PE 1 . 3 x 10-213k1
Hiprotein/ Proof / TEFLON :2 1): 13-2”,“

Hiprotein/Contact/TEFLON

 

143
Table 34: (cont'd)

Treatment Meanl
Pastry/Contact/PE 4.6 x 10'25-5kl
Bread/Contact/TEFLON 3.1 x 10'211‘1
Pastry/Proof/TEFLON 1.1 x 10"”1
Bread/Proof/TEFLON 4.0 x 10"31
Pastry/Contact/TEFLON 3.1 x 10"31
Pastry/None/TEFLON 1.3 x 10'31

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

__J'j_-._

Table 35. thass mean values of room (23°C) and refrigerated
(4°C) temperature with PE, PET, and TEFLON film.

Treatment Mean1
PEI/Refri 3.8 x 10:1a
PE/Room 3.2 x 10_1a
PET/Refri 3.1 x 10_1:
PET/Room 3.0 x 10_1b
TEFLON/Refri 1.1 x 10_2b
TEFLON/Room 8.3 x 10

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

144

Table 36. Wtforce mean values of proof-first, contact-
first, and no-yeast dough.

Yeast Type Mean1
None 39.80a
Proof-first 37.19a
Contact-first 15.61”
1 ........................................................

means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 37. Wtforce mean values of Hi-protein, bread, and
pastry flour.

Flour Type Mean1
Hi-protein 46.47;
Bread 30 0 05¢
Pastry 16 o 09

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

145

Table 38. Wtforce mean values of none, proof-first,
contact-first, and no-yeast dough with Hi-

protein, bread, and pastry flour

None/Hiprotein

None/Bread

Proof/Hiprotein

Proof/Bread

Contact/Hiprotein

None/Pastry

Proof/Pastry

Contact/Bread

Contact/Pastry

1 means followed by the same letters are
different at p < 0.05 by Tukey's HSD Test

not significantly

Table 39. Wtforce mean values of room (23°C) and refrigerated

(4°C) temperature with proof-fir
and no-yeast dough.

Treatment
None/Room
None/Refri
Proof-first/Room
Proof-first/Refri
Contact-first/Refri
Contact-first/Room

1 means followed by the same letter are
different at p < 0.05 by Tukey's HSD Test

st, contact-first,

46.83a
46.10a
30.26b
29.83b
17.86c
14.32c

not significantly

. if “ll—guru— '
'2‘

146

Table 40. Wtforce mean values of room (23°C) and refrigerated
(4°C) temperature with Hi-protein, bread, and pastry

flour.

Treatment Mean1
Hiprotein/Refri 41.10a
Hiprotein/Room 38.51a
Bread/Room 37.41a
Bread/Refri 36.96a
Pastry/Refri 15.73”
Pastry/Room 15.49”

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 41. Wtforce mean values of proof-first, contact-
first, and no—yeast dough with Hi-protein,
bread, and pastry flour at room (23°C) and
refrigerated (4°C) temperature.

Treatment Mean
Hiprotein/None/Refri 61.32:
Bread/None/Room 60.67a
Hiprotein/None/Room 58.35a
Bread/None/erri 56.54b
Hiprotein/Proof/Refri 37.07b
Hiprotein/Proof/Room 35.48b
Bread/Proof/Room 35.40 c
Bread/Proof/Refri 33.34cd
Hiprotein/Contact/Refri 24.91d
Hiprotein/Contact/Room 21.70
Pastry/None/Room 21-47
Bread/Contact/Refri 21.01
Pastry/None/Refri 20-44
Pastry/Proof/Room 19-90
Pastry/Proof/Refri 19.09de
Bread/Contact/Room 16.16ef
Pastry/Contact/Refri 7.67f
Pastry/Contact/Room 5-10

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

147

Table 42. Wtforce mean values of PE, PET, and TEFLON film.

Film Type Mean1
PE 34.80a
PET 34.54a
TEFLON 23.26

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 43. Wtforce mean values of proof-first, contact-
first and no-yeast dough on PE, PET, and TEFLON

film.

Treatment Mean1
None/PE 51.71:
None/PET 49.97b
None/TEFLON 37.72b
Proof-first/PE 34.93b
Proof-first/PET 34.76c
Proof-first/TEFLON 20.45c
Contact-first/PET 18.89c
Contact-first/PE 17.77c
Contact-first/TEFLON 11.61

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

148

Table 44. Wtforce mean values of Hi-protein, bread, and
pastry flour on PE, PET, and TEFLON film.

Treatment Mean
PE/Hi-protein 42.62a
PE/Bread 42.28a
PET/Hi-protein 42.07a
PET/Bread 41.42a
TEFLON/Hi-protein 34.731”
TEFLON/Bread 27.85bc !
PET/Pastry 20.12c ,
PE/Pastry 19.51c 3
TEFLON/Pastry 7.21

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 45. Wtforce mean values of Hi-protein, bread, and
pastry flour with proof-first, contact-f1rst and
no-yeast dough on PE, PET, and TEFLON film.

Treatment Mean
Bread/None/PE 65.85:
Hiprotein/None/PE 63.33a
Hiprotein/None/PET 60.74ab
Bread/None/PET 60.02ab
Hiprotein/None/TEFLON 55.44bc
Bread/None/TEFLON 49.95c
Bread/Proof/PET 42.23c
Bread/Proof/PE 40.79c
Hiprotein/Proof/PET 39.53cd
Hiprotein/Proof/PE 39.35de
Hiprotein/Proof/TEFLON 29.95def
Pastry/None/PET 29.14ef
Pastry/None/PE 25.95ef
Hiprotein/Contact/PET 25.94ef
Hiprotein/Contact/PE 25.18ef
Pastry / Proof / PE 24 . 659:9
Pastry / Proof / PET 3‘2! - 33‘3th

Bread/Contact/PET

149

Table 45 : (cont'd)

Treatment Mean1
Bread / Contact / PE 2 0 . 2 2‘afgh
Bread / Proof [TEFLON 2 0 . 09‘?fgh
Hiprote in / Contact / TEFLON 18 . 79fghi
Bread/Contact/TEFLON 13.529’}ij
Pastry/Proof/TEFLON 11 . 33tujk
Pastry/Contact/PET 8.71ijk
Pastry/Contact/PE 7.92jk
Pastry/None/TEFLON 7.77jk
Pastry/Contact/TEFLON 2.53k

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 46. Wtforce mean values of room (23°C) and refrigerated
(4°C) temperature with PE, PET, and TEFLON f1lm.

Treatment Mean1
PE/Refri 35.32:
PET/Refri 34.84a
PE/Room 34.29a
PET/Room 34.23b
TEFLON/Refri 23.64
TEFLON/Room 22-89

1 means followed by the same letter are not significantly
different at p < 0.05 by Tukey's HSD Test

150

Table 47. thass mean values of proof-first, contact-
first, and no-yeast dough at room (23°C) and
refrigerated (4°C) temperature with PE, PET,
and TEFLON film.

Treatment Mean
None/Refri/PE 6.8 x 10’1'a
None/Room/PE 6.4 x 10'1'Ii
None/Refri/PET 4.3 x 10'3”
None/Room/PET 4.0 x 'd”°
Proof/Room/PET 3.2 x '1”°d
Proof/Refri/PET 3.0 x '1”°d
None/Refri/TEFLON 2.5 x 1 '1Cde
Contact/Refri/PE 2.3 x 10'lde
Proof/Refri/PE 2.2 x 1"me
Proof/Room/PE 2.2 x 10'139
None/Room/TEFLON 2.1 x 1 :1:
Contact/Refri/PET 2.0 x -ddef
Contact/Room/PET 1.7 x 10_2 :
Contact/Room/PE 9.4 x 104:
Contact/Refri/TEFLON 3.7 x 10_2f
Proof/Refri/TEFLON 2.9 x 10__2f
Contact/Room/TEFLON 2.2 x 10-2:
Proof/Room/TEFLON 2.0 x 10

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

Table 48. Wtforce mean values of proof-first, contact-
first, and no-yeast dough at room (23°C) and
refrigerated (4°C) temperature with PE, PET, and

TEFLON film.

None/Room/PE
None/Refri/PE
None/Refri/PET
None/Room/PET
None/Refri/TEFLON
None/Room/TEFLON
Proof/Room/PET
Proom/Room/PE
Proof/Refri/PE
Proof/Refri/PET
Contact/Refri/PE
Proof/Room/TEFLON
Proof/Refri/TEFLON
Contact/Refri/PET
Contact/Room/PET
Contact/Room/PE
Contact/Refri/TEFLON
Contact/Room/TEFLON

34 . 93d°f9
34 . 93‘”afg
34 . 39"“9
20 . 85““9
20 . 73"“9
20. 18‘mfg
20. 06‘1919
17 . 72‘“?
14 . 69°19
12.67f9
10.559

1 means followed by the same letters are not significantly

different at p < 0.05 by Tukey's HSD Test

152
Table 49. thass mean values of Iii-protein, bread, and

pastry flour at room (23°C) and refrigerated
(4°C) temperature with PE, PET, and TEFLON film.

Treatment Mean
Bread/Refri/PE 5.3 x 10'1“
Brfiaci/Rlll/Pli! 4.4 x 10'1"10
Hiprotein/Refri/PE 4.0 x -1abc
Hiprotein/Refri/PET 3.5 x '1”°d
Hiprotein/Rm/PET 3.4 x 10'1”“
Hiprotein/Rm/PE 3.2 x 0'1”“:
Bread/Refri/PET 3.2 x 0'1gcgef
Bread/Rm/PET 2.9 x 0': :1 :
Pastry/Rm/PET 2.5 x 0:12:th
Pastry/Refri/PET 2.5 x 0_1: : :
Pastry/Refri/PE 2.0 x 10__m°f<3h
PastrY/Rm/PE 1.9 x 104;:
Hiprotein/Refri/TEFLON 1.9 x 10__1f :1
Hiprotein/Rm/TEFLON 1.6 x 10%:i
Bread/Refri/TEFLON 1.2 x 104:1
Bread/Rm/TEFLON 9.0 x 10_31
Pastry/Refri/TEFLON 8.0 x 10_31
Pastry/Rm/TEFLON 2.3 x 10

1 means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

153
Table 50. Wtforce mean values of Hi-protein, bread, and

pastry flour at room (23°C) and refrigerated
(4°C) temperature with PE, PET, and TEFLON film.

Treatment Mean1
Hiprotein/Refri/PE 44.05”
Hiprotein/Refri/PET 43.26””
Bread/Refri/PE 42.43””
Bread/Room/PE 42.14””
Bread/Room/PET 41.89””
Hiprotein/Room/PE 41.18””
Bread/Refri/PET 40.95””
Hiprotein/Room/PET 40.88””
Hiprotein/Refri/TEFLON 35.99””c
Hiprotein/Room/TEFLON 33.47”c
Bread/Room/TEFLON 28.19Cd
Bread/Refri/TEFLON 27.52””
Pastry/Refri/PET 20.31”
Pastry/Room/PET 19.93d
Pastry/Room/PE 19.53”
Pastry/Refri/PE 19.48”
Pastry/Refri/TEFLON 7.40e
Pastry/Room/TEFLON 7.01e

means followed by the same letters are not significantly
different at p < 0.05 by Tukey's HSD Test

BIBLIOGRAPHY

“m "l

BIBLIOGRAPHY

Adam, N. R., (1968). The physics and chemistry of surfaces.
Dover : New York, NY.

Alfrey, T. Jr., (1948). Mechanical Behavior of High
Polymers, Wiley-Interscience : New York, NY.

Allan, A. J. G. (1959). The spreading of liquid on
polyethylene film; The effect of preprinting treatments.
Journal of Polymer Science, 38, 297.

Allen, R. W., (1978). Theories of Adhesion. In Booth, K
(Ed.). (1990). Industrial packaging adhesives.

Amend, T., and Belitz, H., (1990). The formation of dough

and gluten - A study by scanning electron microscopy. Z
Lebensm Unters Forsh, 190: 401-409.

Arakawa, T., Morishta, M., and Yonezawa, D., (1976).
Aggregation behaviors of glutens, glutenins and gliadins
from various wheats. Agric. Biol. Chem. 40:1217.

ASTM BULL., (1958). (D907-55), American Society for Testing
Materials, Philadelphia, PA. 706.

Bafford, R.A., (1987). Silicone-free release coatings need
no post-drying cure step. Adhesive Age, 30 (13), 18.

Bartell, F. E., (1931). Wetting of solids by liquids. In
Coll. Chem. by Jerome Alexander. (Vol. 3). pp 41-60.
Chemical Catalog : New York, NY.

Batcher, O. M., Staley, M. G., & Deary, P. A., (1963).
Palatability characteristics of foreign and domestic

rices cooked by different methods. Part II. Rice
Journal, 66 (10), 13.

Berkeley, R. C. W., Lynch, J. M., Melling, J., Rutter, P.

R., 8 Vincent, 8., (Eds.). (1980). Microbial adhesion to
surfaces. Ellis Horwood : London.

154

155

Bietz, J. A., Huebner, F. R., & Wall, J. S
Glutenin °

., (1973).
. The strength protein of wheat flour.
Digest, 47 (2), 26-35.

Bakers
Bikerman, J. J.

(1950). Sliding of drops from surfaces of
different roughness. J. Colloid Sci., 5, 349.
Bikerman, J. J., (1958). Surface chemistry (2nd ed.).
Academic Press : New York, NY.

Bikerman, J. J., (1968). The Science of Adhesive Joints,
(2nd ed.). Academic Press

: New York, NY.
Bikales, N. M., (Ed.). (1971). Adhesion and bonding.
Wiley-Interscience °

. New York, NY.
Bloksma, A.H.,

(1990). Dough structure, dough rheology, and
baking quality. Cereal Food World, 35 (2), 237-244.
Booth, K. (Ed.). (1990). Industrial packaging adhesives.
Blackie : London.

. London.
Surface tension and the spreading of
University Press

Cagampang, G. B., Griffith, J. E.,
(1981).

Briston, J. H., & Katan, L. L., (1974). Plastics in contact
with food (lst ed.). Food Trade Press
Burdon, R. 8.,

(1949).
liquids (2nd ed.).

. Cambridge.

& Kirleis, A. W.,

Modified adhesion test for measuring stickiness

of sorghum porridges. Cereal Chem., 59, (3), 234-235.

Campion, R. P. (1975). Adhesion 1, ed. Allen, K.W.,
Science : London, Chap 5.

Applied
Cherry, J. P.,

(Ed.). (1981). Protein functionality in food.
American Chemical Society : Washington, D. C..

Claassens, J. W., (1958). The adhesion-cohesion, static
friction and macro-structure of certain butters. I. A
method of measuring the adhesion—cohesion of butter.
South Afr. Journal Agriculture Science, 1, 457.

Curley, P., & Hoseney, R. C., (1983). Effects of corn
sweeteners on cookie quality. Cereal Chem., 61, (4),
274-278.

DeBruyne, N. A., & Houwink, R. (Eds.). (1951). Adhesion and
adhesives. Elsevier : Amsterdam.

156

D'egidio, M. G., Sgurlletta, D., Nardi, S., Galterio, G., De
Stefanie, E., Fortini. S., & Bozzini, A., (1982).
Standardization of cooking quality analysis in macaroni
and pasta products. Cereal Foods World, 27, 367.

DeMan, J. M., Voisey, P. W., Rasper, V. P., & Stanley, D. W.

(Eds.). (1976). Rheology and texture in food quality.
AVI. : Westport.

DePontanel, H. G., (Ed.). (1972). Protein from hydrocarbons.
Academic Press : London.

Derjaguin, B. V., & Smilga, V. P., (1969). "Adhesion
Fundamentals and Practice". McLaren : London.

Dexter, J. E., Kilborn, R. R., Morgan, B. C., & Matsuo, R.
R., (1980). Grain research laboratory compression
tester: Instrumental measurement of cooked spaghetti
stickiness. Cereal Chem., 60, (2), 139-142.

Dexter, J. E., Matsuo, R. R., & Morgan, B. C., (1983).
Spaghetti stickiness: Some factors influencing stickiness
and relationship to other cooking quality
characteristics. J. food Science, 48, 1545-1551.

Diehl, K. C., & Hamann, D. D., (1979). Structural failure
in selected raw fruits and vegetables. J. Texture
Studies 10 (4): 371-375.

Dupre, A. (1869) . Theoric mechanique de la chaleur, Gauthier-
Villars : Paris.

Eley, D. D. (Ed.). (1961). Adhesion, University Press :
Oxford.

Ewart, J.A.D., (1972). Recent research and dough visco-
elasticity. Baker's Digest, 46 (8), 22-28.

Farid, M., & Faubion, Jon M. (Eds). (1990). Dough rheology

and baked product texture. Van Nostrand Reinhold : New
York, NY.

Fellers, D. A., & Deissinger, A. E., (1982). Preliminary
study on the effect of steam treatment of rice paddy on

milling properties and rice stickiness. J. Cereal Sci.,
1, 147-157.

Ferrel, R. E., Kester, E. B., & Pence, J. W. (1960). Use of
emulsifiers and emulsified oils to reduce cohe51on 1n
canned white rice. Food Technol. 14, 102.

157

Finney, K. F., Morris, V. H., 8 Yamazaki, W. T., (1950).
Micro versus macro cookie baking procedures for

evaluating the cookie quality of wheat varieties. Cereal
Chem., 27, 42.

Fowkes, F. M., 8 Sawyer, W. M. (1952). Contact angles and

boundary energies of a low energy solid. J. Chem. Phys.,
20, 1650.

Frisch, H.L., Gaines, G.L., J., 8 Schonhorn, H., (1976).
Polymer surfaces. In "Treaties on Solid State Chemistry",

Vol 68 Surfaces II. Hannay, N.B. ed., Plenum Press : New
York, NY.

Gaines, C. S., (1981). Technique for objectively measuring a
relationship between flour chlorination and cake crumb
stickiness. Cereal Chem., 59 (2), 149-150.

Gaines, C.S., and Kwolek, W.F., (1982). Influence of
ambient temperature, humidity, and flour moisture content
on stickiness and consistency in sugar-snap cookie
doughes. Cereal Chem., 59 (6), 507-509.

Gent, A. N., (1982). The strength of adhesive bonds.
Adhesive Age. 25 (2). 27-34.

Good, R. J., (1964). Theory for the estimation of surface and
interfacial energies. Contact Angle, Wettability and
Adhesion, Am. Chem. Soc. Ser. No. 43, 74.

Good, R. J., and Girifalco, J., (1960). A theory for
estimation of surface and interfacial energies. III.
Estimation of surface energies of solid from contact angle
data. Journal Physical Chemistry, 64, 561.

Gortner, R.A., and Doherty, E.H., (1918). Hydration capacity
of gluten from strong and weak flours. J. Agric.
Research, 13, 389.

Hair, M.L., (1967). "Infrared Spectroscopy in Surface
Chemistry". Marcel Dekker : New York, NY.

Harkins, W. D., (1917). The orientation of molecules in the
surfaces of liquids, the energy relations at surfaces,
solubility, emulsification, molecular association and the
effect of acids and bases on interfacial tension.
(Surface energy VI). J. Am. Chem. Soc, 39, 541-596.

Hindman, H., 8 Burr, G. S., 1949. The Instron tensile
tester. Trans. Am. Soc. Mech. Eng., 71, 789-796.

158

Hlynka, I., (1959).

Dough mobility and absorption. Cereal
Chem., 36:378.

Hlynka, I., (1962). Dough structure - Its basis and
implication.

Baker's Digest, 36 (10), 44.

Hlynka, 1., (Ed.). (1964). Wheat chemistry and technology.
American Association of Cereal Chemists : St. Paul.

Hlynka, I., (1970). Rheological properties of dough and
their significance in the breadmaking process. Baker's
Digest, 44 (2) 20-41, 44-46, 57.

Hoseney, R. C., Finney, K. F., Shogren, M. D., 8 Pomeranz,
Y., (1969). Cereal Chem., 46, 126.

Hoseney, R. C., 8 Finney, P. L., (1974). Mixing - A
contrary view.

Baker's Digest, 48, (1), 22-28, 66.

Hoseney, R. C., 8 Seib, P. A.,

(1978).
table.

Cereal Food World, 23 (7),

iHuntsberger, J. R. (1963). The locus of adhesive failure.
Polymer Sci., A1, 1339.

Bread: From grain to
362-367.

J.

Houwink, R., 8 Salomon, G.,

(1965). Adhesion and adhesives
(Vol.1). (2nd rev. ed.). Elsevier : Amsterdam.
Jackel, 8.8., (1969). Fermentation flavors of white bread.

Baker's Digest 43 (5), 24.

Johnson, R. E. Jr., 8 Dettre, R. H., (1964). Contact angle
hysteresis. Part I and II. Contact Angle, Wettability,
and Adhesion, Am. Chem. Soc. Ser., No. 43, 112, 136.

Juliano, B. 0., Ofiate, L. U., 8 del Mundo, Angelita, M.,
(1965).

Relation of starch composition, protein content,
and gelatinization temperature to cooking and eating
qualities of milled rice. Food Technology, 19, 116.

Kasarda, D.D., Bernardine, J.E., and Nimmo, C.C., (1976).
Advances in Cereal Science and.Technology. (Y. Pomeranz,
ed.) p. 158. AOAICOC. St. Paul, Minn.

Kawasaki, K. (1960). Study of wettability of polymers by
sliding of water drop. J. Colloid Sci., 15, 402.

Khoo, U., Christianson, D. D., Inglett, G. E., 1975.

Scanning
and transmission microscopy of dough and bread. Baker's
Digest, 49 (8), 24-26.

159

Kilborn, R. H., Tipples, K. H., 8 Preston, K. P., (1982).
The GRL compression tester: Description of the instrument
and its application to the measurement of bread crumb
properties. Cereal Chem. 60:134.

Kiosseoglou, V.D., 8 Sherman, P. (1983). The rheological
conditions associated with judgement of pourability and
spreadability of salad dressings. Journal Texture
studies. 14 : 277-282.

Kretovich, V. L., (Ed.). (1965). Biochemistry of grain and
breadmaking. Israel Program for Scientific
Translation : Jerusalem.

Kumar, B. M., Upadhyay, J. K., 8 Bhattacharya, K. R.,
(1975). Objective tests for the stickiness of cooked
rice. Journal of Texture Studies, 7, 271-278.

Lai, C.C., (1985). Interfacial properties between food
stuffs and packaging surface. 4th International
conference on Packaging. East Lansing, MI.

Lai, C.C., (1987). Sticky problems in food packaging. In
"Food Product-Package Compatibility". Gray, I., Harte,
B., 8 Miltz, J., ed. Technomics : Lancaster.

Lai, C.C., (1988). Flow of semi-solid foods over inclined
packaging surfaces as an index of traction. JTEVA
16 : 140.

Langmuir, I., (1916). The constitution and fundamental
properties of solids and liquids. I. Solids. J. Am.
Chem. Soc., 38, 2221-95.

Larsen, R.A., (1964). Hydration as a factor in bread flour
quality. Cereal Chem., 41:181.

Lebedev, Y.A., Baranov, V.F., Negrub, V.P., and Chernov,
N.E. 1975. Influence on micro relief on mutual adhesion
between moulder and spaghetti dough. Khlebopek.
Konditer. Prom. No. 5, pp. 26-7.

Levine, M., Ilkka, G., 8 Weiss, P., (1964). Wettability of
surface-treated metals and the effect on lap shear
adhesion. adhesives Age, 7 (6), 24.

Manly, R. 8., (Ed.). (1970). Adhesion in biological system.
Academic Press : New York, NY.

Matsumoto, H., Nishiyama, J., Mita, T., 8 Kuninori, T.,
(1975). Rheology of fermenting dough. Cereal Chem. 52:
82r-88r.

160

Matz, S. A., (Ed.). (1960). Bakery °

. Technology and
engineering. AVI : Westport.

Mecham, D. K., (1973).

Wheat and flour proteins.
Digest. 47 (10).

Bakers
24-32.

Motegi, S., (1979). Effect of adhesiveness of packaging

film.to meat on the growth of microorganisms responsible
for the deterioration of fish sausage.

Bull. Jap. Soc.
Fish. 45 : 89.

Montejano, J. G., Hamann, D. D., 8 Lanier, T. C.

(1983).
Final strengths and rheological changes during processing

of thermally induced fish muscle gels. J. Rheology 27(6)
557-579.

Mossman, A. P., 8 Fellers, D. A., (1976). Reduction of
stickiness in rice.

Cereal Foods World, 21, 422.

Mossman, A. P., Fellers, D. A., 8 Suzuki, H., (1975). Rice
stickiness. I. Determination of rice stickiness with an
Instron Tester. Cereal Chem., 60 (4), 286-292.

Noguchi, G., Shinya, M., Tanaka, K., 8 Yoneyama, T.,

(1976).
Correlation.of dough stickiness with.texturometer reading

and with various quality parameters. Cereal Chem., 53
(1), 72-77.

Orth, R. A.,

8 Bushuk, W., 1972. A comparative study of the

proteins of wheats of diverse baking qualities. Cereal
Chem., 49, 268.

Osborne, T. b., (1907). The protein of the wheat kernel,

Publication No. 84. Carnegie Institution of Washington.
Also Am. Chem. Jour. (1983). pp. 392.

Padday, J. F., (Ed.).

(1978). Wetting, spreading, and
adhesion.

Academic Press : London.

Parker, R. S. R.,

8 Taylor, P., 1966.
adhesives.

Adhesion and
Pergamon Press : London.

Patrick, R. L., (Ed.). (1967). Treatise on adhesion and
adhesives (Vol. 1). Marcel Dekker : New York, NY.

Pomeranz, Y. (Ed.). (1964). Wheat chemistry and technology.
American Association of Cereal Chemists :

St. Paul.
Pomeranz, Y., 1980.

Molecular approach to breadmaking : An
update and new perspectives. Baker's Digest, 54 (1), 20.

 

161

Product specification from Eastman Chemicals. Publication
No. ZM-lG, August 1986.

Pyler, E. J., (Ed.). (1973). Baking science 8 technology
(Vol. 1). Siebel : Chicago.
Pyler, E. J., (1988).

(3rd. ed.) (Vol. 1,
8 technology.

2). Baking science
Sosland : Merriam.
Ray, B. R., Anderson, J. R., 8 Scholz, J. J. (1958). Wetting
of polymer surfaces. I. Contact angles of liquids on
starch, amylose, amyIOpectin, cellulose, and polyvinyl
alcohol. Journal Phys. Chem., 62, 1220.
Sanjiva, R. B., (1938). Investigation on rice. Current

Science (India), 6, 446.

Schmitz, J. V., (1966).

Testing of polymers (Vol. 2).
Interscience : London.

Sharpe, L. H., 8 Schonhorn, H., (1964).

Surface energetics,
adhesion, and adhesive joints. Advances Chemistry Ser.,
43, 189.

Sharpe, L. H., (Ed.). (1988). Adhesion international 1987 :
Proceedings of the 10th annual meeting of the adhesion
society Inc.. Gordon and Breach Science

. New York, NY.

Advances in ingredient testing
Cereal Food World, 23 (4), 187-190.
Stear, C. A., (1990).

Handbook of breadmaking technology.
Elsevier Applied Science : London.

Sietz, W., (1978).
equipment.

Steele, R.J., and Davis, E.G.

1979. Adhesion of fruit
cakes to aluminum trays.

CSIRO Id. Res. 0. 39:30.
Swanson, C. O., (1943). Physical properties of dough.
Burgess : Minneapolis.

Taguchi, T., Kikuchi, K., Tanaka, M., 8 Suzuki, K.,

(1979).
Adhesion of canned mackerel meat. Bull. Jap. Soc. Sci.
Fish., 46, (3), 369-372.

Thomasos, F. I., 8 Wood, F. W.,

(1963). Some factors
influencing stickiness of butter. J. Dairy Research, 31,
137-146.

Tkachuk, R., 8 Hlynka, I., 1968. Some properties of dough
and gluten in D20. Cereal Chem., 45, 203-205.

162

Upson, F. W., 8 Calvin, J. W. (1916). The colloidal
swelling of wheat gluten in relation to milling and
baking.

Nebr. Agr. Expt. Sta. Res. Bul. 8.

Vallery-Radot, L.P., 1957. The pasteur fermentation
centennial. A Scientific Symposium, Chas. Pfizer 8 Co.,
Inc., New York.

Vasenin, R. M., (1965). Adhesion of high polymers.

Part I °
The phenomenon of adhesion.

Adhesive Age, 8 (5), 21.

Voisey, P. W., Wasik, R. J., 8 Loughheed, T. C., (1978).
Measuring the texture of cooked spaghetti. II.

Exploratory work on instrumental assessment of stickiness
and its relationship to microstructure. Can. Inst. Food
Sci. Tech. J., 11, 180.

Voyutskii, S. S., (1963). Autohesion and adhesion of high
polymer, Wiley - Interscience

. New York, NY, PP 127.

Wall, J.S., (1967). Origin and behavior of flour proteins.
Baker's Digest, 41 (5), 36.

Wall, J.S., (1971). Disulfide bonds : Determination,

location, and influence on molecular properties of
protein. J. Agric. Food. Chem., 19, 619.

Wall, J.S., (1979). Properties of proteins contributing to
functionality of cereal foods. Cereal Food World, 24,
(7), 288-292.

Wall, J. S., 8 Beckwith, A. C., 1969. Relationship between

structure 8 rheological properties of gluten proteins.
Cereal Sci. Today, 14 (1), 16.

Wetting : A discussion covering both fundamental and applied
aspects of the subject of wetting and wettability.

(S.C.I. Monograph No. 25). Society of Chemical Industry :
London; 8 Gordon 8 Breach : New York, NY.

Williams, M., 1990.

New items give refrigerated dough a
lift (at supermarkets). Supermarket News, March 5, 1990,
p. 29 (1).

Yokoyama, K., (1966). Studies on adhesion of meat material

on casing in fish sausage and Kamaboko-I. Some trial to
estimate the degree of adhesion.

Bull. Jap. Soc. Sci.
Fish., 32, (12), 1023-1030.

163

Yokoyama, K., (1974). Studies on adhesion of fish meat
products on casing in fish sausage and kamaboko - IV.
Effect of different kinds of plastic casings on the rate
of wettability and adhesion. Bull. Jap. Soc. Sci. Fish.,
40, (8), 799-805.

Young, C. B. F., 8 Coons, K. W., (1945). Surface active
agents. Chemical : New York, NY.

Young, T., (1805). An essay on the cohesion of fluids. Phil.
Trans. Roy. Soc. 95 : 65. London.

Zisman, W. A. (1962). Adhesion and Cohesion, (Weiss, P.,
ed), Elserier : Amsterdam.

Zisman, W. A. (1963). Influence of constitution on adhesion.
Industrial Engineering Chemistry, 55, 18.

Zisman, W. A. (1964). Relation of the equilibrium contact
angle to liquid and solid constitution. Kendall Award
Address, in Contact Angle, Wettability, and Adhesion, No.
43, Advances in Chemistry Series, 43, 1.

   

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