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A in! .L E

THE-ass

lIBRARY
Michigan State
University

This is to certify that the
thesis entitled
Evaluation of Fluid Foods Using a Helical Ribbon
Viscometer

presented by

Eva Agrawal

has been accepted towards fulfillment
of the requirements for

MS degree in Food Science

 

 

, 1m ,5. Jéfl
Major professor
Date 9/H1/0/

0-7639 MS U is an Affirmative Action/Equal Opportunity Institution

PLACE IN RETURN BOX to remove this checkout from your record.
TO AVOID FINES return on or before date due.
MAY BE RECALLED with earlier due date if requested.

 

DATE DUE

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6/01 cJCIRC/DateDue.p65-p.15

 

EVALUATION OF FLUID FOODS USING A HELICAL RIBBON
VISCOMETER
By

Eva Agrawal

A THESIS

Submitted to
Michigan State Univerisity
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE
Department of Food Science and Human Nutrition

2001

ABSTRACT
EVALUATION OF FLUID FOODS USING A HELICAL RIBBON
VISCOMETER
By

Eva Agrawal

A helical ribbon impeller was calibrated and evaluated for use in the
rheological testing of food products. Constants that characterize the helical
ribbon were evaluated: k” (mixer coefficient) equaled 1632 rev/m3; and k’
(mixer viscometer constant) ranged from 3 — 11 l/rev. Higher values of k’
corresponded to lower flow behavior indices, and lower angular velocities.
The helical ribbon was found to be very effective in testing rheological
properties of highly viscous, non — homogenous, yield stress fluids such as
mustard, ketchup, and salad dressing. The change in textural properties of
Mayonnaise and Miracle Whip (at 5°C, 21°C, and 37°C) were studied by
observing changes in the apparent viscosity with the addition of water at the
shear rates corresponding to those found in the mouth. The addition of water
in the sample was scaled up to match the bolus, saliva volume, and flow rate.
Rheological data showed clear differences in the change in apparent

viscosity at different temperatures and fat levels.

DEDICATION

To my wonderful family

for their love, support and encouragement.

iii

ACKNOWLEDGEMENTS

I would like to extend my gratefulness to Dr. James Steffe for his invaluable
guidance and advice from time to time in absence of which, this research
and thesis would have been impossible. I appreciate his time and efforts

devoted to this project.

I am thankful to Dr. Maurice Bennink and Dr. Gale Strasburg for serving on
my committee. I am thankful for their suggestions and time they have spent

on this work.

I am also grateful to Dr. Jim Bay Loh from Kraft Foods Inc. for his guidance
during the studies and I thank the company for funding and supporting the
project. I am also thankful to Mr. Richard Wolthuis for constructing the

helical ribbon used during this research.

Further I would like to extend my special thanks to all my friends for their
love and support. Last but not the least, I would like to extend my heart felt
thanks to my wonderful parents and brother for their endless sacrifices,

support, and encouragement throughout my life.

TABLE OF CONTENTS

List of Tables
List of Figures

Nomenclature

CHAPTER 1
INTRODUCTION
Objectives

CHAPTER 2
LITERATURE REVIEW
2.1 Oral Factors
2.1.1 Saliva
2.1.2 Oral Cavity
2.2 Mayonnaise and Miracle Whip
2.3 Mixer Viscometer Constant (k’)

CHAPTER 3
THEORETICAL DEVELOPMENT
3.1 Flow Regime During Mixing and k”
3.2 Mixer Viscometer Constant, k'

CHAPTER 4

MATERIALS AND METHODS

4.1 Experimental Equipment

4.2 Characterization of Helical Ribbon
4.2.] Determination of k”
4.2.2 Determination of k’

4.3 Evaluation of Helical Ribbon

4.4 Evaluation of Physical Changes in Food Emulsions with
Addition of Water
4.4.1 With Automatic Water Injection

Page
vii
xi

XV

v—au—a\OL/1£J]U|

(Jib—a

16
16
18

20
20
25
25
3O
33

35
38

4.4.2 With Manual Mixing
4.5 Evaluation of Kraft Miracle Whip with Different Textural
Properties

CHAPTER 5

RESULTS AND DISCUSSION

5.1 Characterization of the Helical Ribbon
5.1.1 Evaluation of k”
5.1.2 Evaluation of k’

5.2 Evaluation of the Helical Ribbon

5.3 Evaluation of Physical Changes in Food Products with
Addition of Water During Mixing
5.3.1 Automatic Water Injection
5.3.2 Manual Mixing of Water

5.4 Analysis of Kraft Miracle Whip with Different Textural
Characteristics

CHAPTER 6
CONCLUSIONS AND SUMMARY

CHAPTER 7
RECOMMENDATIONS FOR FUTURE STUDY

APPENDIX

BIBLIOGRAPHY

vi

41
43
45
45
45
47
56
59
61
74

100

106

108

109

138

Table

4.1.

4.2.

4.3.

4.4

4.5

5.1

5.2

5.3

5.4

5.5

A.1

LIST OF TABLES

Newtonian fluids used with the helical ribbon impeller to
evaluate k’.

Range of angular velocity (rpm) for Newtonian fluids with
different viscosities as calculated using the Reynolds

number.

Non — Newtonian fluids used with the helical ribbon
impeller to evaluate the value Of k’.

Maj or ingredients present in the five food products

Scaled — up numerical values used during the experiments
to meet the conditions existing in the oral cavity

Values of flow behavior index (n) and mixer viscometer
constant (k’) for guar gum (GG) and HPMC at different
concentrations.

Comparison of consistency coefficient (K) and shear —

thinning indices (11) for typical food products as obtained

with helical ribbon and concentric cylinder systems.

Slopes Obtained for all food products at 5°C at 25 l/sec

Slopes obtained for all food products at 21°C at 25 l/sec

Slopes obtained for all food products at 37°C at 25 l/sec

Data for silicon oil with viscosity 0.490 cp used during
the determination of k”.

vii

Page

27

29

32

36

37

55

58
100
101

102

110

A2

A3

A.4

A.5

A.6

A.7

A.8

A.9

A.10

A.11

A.12

A.13

Data for glycerin with viscosity 0.740 cp used during
the determination of k”.

Data for silicon oil with viscosity 5.20 cp used during
the determination of k”.

Data for silicon oil with viscosity 5.30 cp used during
the determination of k”.

Data for the determination of k”using the Newtonian
fluids.

Data sets for K and n values for guar gum at different
concentrations.

Data sets for K and n values for HPMC at different
concentrations.

Data for determination of k’at different angular velocities
for guar gum at different concentrations.

Data for determination of k’at different angular velocities
for HPMC at different concentrations.

Rheograms obtained for different food products
comparing the results obtained from MVl and Helical
Ribbon systems.

Data for Kraft Fat Free Mayonnaise at different
temperatures with automatic addition of 8.5 ml water at

4.0 ml/min.

Data for Kraft Light Mayonnaise at two temperatures
with automatic addition of 8.5 ml water at 4.0 ml/min.

Data for Kraft Real Mayonnaise at 5C temperature
with automatic addition of 8.5 ml water at 4.0 ml/min.

viii

110

111

111

112

113

115

117

118

119

121

122

123

A.14

A.15

A.16

A.17

A.18

A.19

A20

A21

A22

A23

A24

A25

Data for Kraft Miracle Whip at different temperatures
with automatic addition of 8.5 ml water at 4.0 ml/min.

Data for Hellmann’s Real Mayonnaise at two temperatures
with automatic addition of 8.5 ml water at 4.0 ml/min.

Data for all the food products at 5°C at 1.25 l/sec shear rate
with automatic addition of 8.5 ml water at the rate of
4.0 ml/min.

Data for all the food products at 21°C at 1.25 l/sec shear
rate with automatic addition of 8.5 ml water at the rate
of 4.0 ml/min.

Data for all the food products at 37°C at 1.25 l/sec shear
rate with automatic addition of 8.5 ml water at the rate
of 4.0 ml/min. '

Data for Kraft Fat Free Mayonnaise at three temperatures
at l l/sec shear rate with manual mixing.

Data for Kraft Light Mayonnaise at three temperatures
at 1 1/sec shear rate with manual mixing.

Data for Kraft Real Mayonnaise at three temperatures
at l l/sec shear rate with manual mixing.

Data for Kraft Miracle Whip at three temperatures at 1
l/sec shear rate with manual mixing.

Data for Hellmann’s Real Mayonnaise at three temperatures
at 1 1/sec shear rate with manual mixing.

Data for Kraft Fat Free Mayonnaise at three
temperatures at 25 l/sec shear rate with manual mixing.

Data for Kraft Light Mayonnaise at three temperatures
at 25 l/sec shear rate with manual mixing.

ix

124 '"

125

126

128

129

130

130

130

131

131

132

132

A26

A27

A28

A.29

A30

A31

A.32

A33

A34

A35

A36

A37

Data for Kraft Real Mayonnaise at three temperatures at 25
l/sec shear rate with manual mixing.

Data for Kraft Miracle Whip at three temperatures at 25
l/sec shear rate with manual mixing.

Data for Hellmann’s Real Mayonnaise at three temperatures
at 25 l/sec shear rate with manual mixing.

Data for Kraft Fat Free Mayonnaise at three temperatures at
50 l/sec shear rate with manual mixing.

Data for Kraft Light Mayonnaise at three temperatures
at 50 l/sec shear rate with manual mixing.

Data for Kraft Real Mayonnaise at three temperatures at
50 1/sec shear rate with manual mixing.

Data for Kraft Miracle Whip at three temperatures at 50
l/sec shear rate with manual mixing.

Data for Hellmann’s Real Mayonnaise at three temperatures
at 50 l/sec shear rate with manual mixing.

Data for all products at 5°C at 25 l/sec shear rate with
manual mixing.

Data for all products at 21 °C at 25 l/sec shear rate with
manual mixing.

Data for all products at 37°C at 25 l/sec shear rate with
manual mixing.

Data for all Kraft Miracle Whip samples at 21°C at 25 l/sec
shear rate with manual mixing.

132

133

133

134

134

134

135

135

136

136

136

137

LIST OF FIGURES

Figures Page
4.1 Haake VT 550 Rotational Viscometer 21
4.2 MV 1 Concentric Cylinder System 22
4.3 Helical Ribbon and Cylinder System 23
4.4 Complete dimensions for helical ribbon and sample cup 24
4.5 Multi — Channel Syringe pump 26
5.1 Plot obtained for the determination of k”using the

Newtonian Fluids 46
5.2 K and n values for guar gum at different concentrations 48
5.3 K and n values for HPMC at different concentrations 49
5.4 k’at different angular velocities for guar gum at different

concentrations 5 1

5.5 k’at different angular velocities for HPMC at different

concentrations 52
5.6 Mixer viscometer coefficient k’and flow behavior index (n)
for guar gum and HPMC at different concentrations ' 54

5.7 Rheograms of different food products comparing results
from Haake concentric cylinder MVl and helical
ribbon (HR) systems 57

5.8 Kraft F at Free Mayonnaise at different temperatures during the
addition of 8.5 ml water at the rate of 4.0 ml/min (with
automatic addition of water) 62

xi

5.9

5.10

5.11

5.12

5.13

5.14

5.15

5.16

5.17

5.18

5.19

Kraft Light Mayonnaise at different temperatures during the
addition of 8.5 ml water at the rate of 4.0 ml/min (with
automatic addition of water)

Kraft Real Mayonnaise at different temperatures during the
addition of 8.5 ml water at the rate of 4.0 ml/min (with
automatic addition of water)

Kraft Miracle Whip at different temperatures during the
addition of 8.5 ml water at the rate of 4.0 ml/min (with
automatic addition of water)

Hellmann’s Real Mayonnaise at different temperatures
during the addition of 8.5 ml water at the rate of 4.0 ml/min
(with automatic addition of water)

Food products at 5°C at 1.25 l/sec shear rate during the
addition of 8.5 ml water at the rate of 4.0 ml/min (with
automatic addition of water)

Food products at 21°C at 2.5 l/sec shear rate during the
addition of 8.5 ml water at the rate of 4.0 ml/min (with
automatic addition of water)

Food products at 37°C at 1.25 l/sec shear rate during the
addition of 8.5 ml water at the rate of 4.0 ml/min (with
automatic addition of water)

Kraft Fat Free Mayonnaise at three temperatures at l l/sec
shear rate (manual mixing)

Kraft Light Mayonnaise at three temperatures at 1 1/sec
shear rate (manual mixing)

Kraft Real Mayonnaise at three temperatures at l l/sec
shear rate (manual mixing)

Kraft Miracle Whip at three temperatures at l l/sec shear
rate (manual mixing)

xii

63

64

65

66

69

70

71

76

77

78

79

5.20

5.21

5.22

5.23

5.24

5.25

5.26

5.27

5.28

5.29

5.30

5.31

5.32

Hellmann’s Real Mayonnaise at three temperatures at 1
l/sec shear rate (manual mixing)

Kraft Fat Free Mayonnaise at three temperatures at 25
l/sec shear rate (manual mixing)

Kraft Light Mayonnaise at three temperatures at 25 l/sec
shear rate (manual mixing)

Kraft Real Mayonnaise at three temperatures at 25 l/sec
shear rate (manual mixing)

Kraft Miracle Whip at three temperatures at 25 l/sec
shear rate (manual mixing)

Hellmann’s Real Mayonnaise at three temperatures at
25 l/sec Shear rate (manual mixing)

Kraft Fat Free Mayonnaise at three temperatures at 50
l/sec shear rate (manual mixing)

Kraft Light Mayonnaise at three temperatures at 50 l/sec
shear rate (manual mixing)

Kraft Real Mayonnaise at three temperatures at 50 1/ sec
shear rate (manual mixing)

Kraft Miracle Whip at three temperatures at 50 l/sec shear
rate (manual mixing)

Hellmann’s Real Mayonnaise at three temperatures at 50
l/sec shear rate (manual mixing)

All food products at 5°C at shear rate 25 l/sec (manual
mixing)

All food products at 21 °C at shear rate 25 l/sec (manual
mixing)

xiii

80

83

84

85

86

87

88

89

90

91

92

95

96

5.33 All food products at 37°C at shear rate 25 l/sec (manual
mixing) 97

5.34 A11 Miracle Whip samples at 21°C at shear rate 25 l/sec
(manual mixing) 104

xiv

kl
kl,

NOMENCLATURE

system constant, l/rev

impeller diameter, m

height of the impeller or bob, m

mixer viscometer constant, l/rev

mixer coefficient, rev/m3

consistency coefficient, Pa sn

mass, g

torque, N m

flow behavior, dimensionless

angular velocity, rev/s

power number, dimensionless

impeller Reynolds number, dimensionless
power, N m/s

radius of bob or impeller, m

radius of cup, m

volume, ml

maximum volume of water added to the food sample, ml

the volume of water added to the particular food sample, ml
constant, Rc /Rb
stress, Pa

angular velocity, rad/sec

XV

apparent viscosity, Pa 5
density, kg / m3

shear rate, US

average shear rate, l/s

Newtonian viscosity, Pa 5

CHAPTER 1

INTRODUCTION

Rheology deals with the response of any material to the applied stress or
strain; hence, it is the study of deformation and flow of material. It has wide
applications in varied fields including geology and mining, concrete
technology, soil mechanics, plastics, and many other areas. In the food
industry, it is particularly helpful in quality control, product development (to
evaluate ingredient functionality), shelf life determination, sensory

evaluation, and process engineering calculations.

Viscosity is an important variable that determines the texture of fluid food,
contributes to the overall mouth — feel, and influences the intensity of flavor
(Houska et a1, 1998). It is represented by the ratio of shear stress and shear
rate, which gives the basic Newtonian model that describes the flow

behavior of simple fluids:

0=fl7 nu

Fluids including water, honey, corn syrup, and vegetable oil in which the

viscosity remains constant with changing shear rate exhibit Newtonian

behavior. The power law model is often used to model the flow behavior of

fluids in which the apparent viscosity varies with the shear rate:

77 = K7714 [1.2]

Fluids like apple sauce, banana puree, orange juice concentrate that depict
decrease in apparent viscosity (n < l) with increase in shear rate are termed
as pseudoplastic (shear — thinning) fluids, and fluids like corn starch
solutions that depict increase in apparent viscosity (n > 1) with shear rate are

termed dilatent (shear — thickening) fluids.

Power law fluids have been extensively tested using mixer viscometers for
quality control and engineering designing applications. Mixer viscometry
has been helpful in assessing fluids exhibiting slip, time — dependent
behavior, having large sized particles, and particle -— settling problems.
Traditional viscometers including concentric cylinder system, plate and cone
system, and parallel plate system have been used in the past for rheological
studies but encountered errors with emulsion type, yield stress possessing
semi -— solid foods due to wall slip and in non — homogenous foods due to its
particulate nature leading to settlement of particles or clogging of particles in

the clearance.

The helical ribbon is an under — utilized mixer impeller designed for the
study of non — homogenous, yield stress fluids. This system reduces the wall
slip, keeps particles suspended, provides a suitable clearance for larger
particles, and provides good agitation during the testing. Thus, this system,
once calibrated, can be used for the studies of textural properties of
emulsions and other yield — stress — possessing fluids that can be utilized in
product improvement and development keeping consumer acceptance in

view.

In mixer viscometry, properties of fluids are evaluated on the basis of a
shear rate estimation which involves the determination of impeller
calibration constants based on the matching viscosity concept. The basis of
the matching viscosity method lies in the comparison of the power curves
for Newtonian fluids and the non — Newtonian fluids, and leads to the
concept that the viscosity of Newtonian fluids is equivalent to the apparent
viscosity of the non — Newtonian fluids at equivalent shear rates. This

concept was used in the current study.

Ingested food undergoes various physical changes in the oral cavity that

correlate to mouth feel. The instrumental evaluation of textural changes in

mouth can be further related to sensory analysis and this information can be
utilized in developing products with desired texture. For instrumental
emulation of mastication, saliva or saliva replacement needs to be uniformly
incorporated into the sample. Traditional viscometers encounter problems
like wall slip and improper mixing of sample and water, so a new impeller
was required to overcome these limitations. Hence, a helical ribbon has been
designed that can effectively mix the water into the sample while avoiding

wall slip and settling of the particles.

Objectives

The overall goal of this project was to develop a helical ribbon mixer

viscometer for viscous fluid foods with the potential to emulate

mastication. There were three specific objectives:

1. To calibrate a helical ribbon impeller for fluid foods by determining
the mixer coefficient (k ”) and the mixer viscometer constant (k’).

2. To evaluate the efficacy of the helical ribbon impeller with typical
food products.

3. To observe the effect of water addition on the rheological properties
of Mayonnaise and Miracle Whip determined with the helical ribbon

system.

CHAPTER 2

LITERATURE REVIEW

2.] Oral Factors
Any edible material when placed in the mouth is subjected to physical
and chemical changes due to the various factors related to oral cavity
including incorporation of saliva, application of force by the teeth,
tongue, cheeks, palate and floor of the mouth. In this study, this aspect of
ingestion where major textural modifications are incurred was evaluated
instrumentally. These results can be related to the sensory analysis data to
develop new products with more desirable texture and mouth feel. The
study concentrated on two different emulsion type products: mayonnaise

and miracle whip.

2.1.1 Saliva

Saliva is the most important aqueous portion of the oral milieu and
contains secretions of the major and minor salivary glands along with
bacteria, food debris and fluid from the gingival crevice. The secretion of
the major and the minor salivary glands mainly determines the

composition of the saliva. It is a vital fluid involved in digestion,

antibacterial activity, buffering, lubrication, water balance and excretion

(Roth and Calmes, 1981 ).

Saliva secretion occurs through three major glands present in the mouth —
submandibular, parotid and sublingual. Numerous minor salivary glands
present in the palate, tongue, lower lip, cheeks and pharynx also
contribute to the total volume of saliva. Also, the gingival crevice is
reported to secrete liquid from the epithelium of gums (Brill, 1962). The
submandibular gland is the major contributor of saliva providing 60 - 65
% of the total saliva secreted. Parotid (22 - 30%), sublingual (2 - 4%) and
minor salivary glands (<10%) follow the submandibular system (Roth
and Calmes, 1981). Secretion of saliva through the three different glands
is complicated since the composition and contribution of each gland
varies with the stimulus and conditions prevailing in the mouth. Also, the
rate of secretion and the composition of saliva vary in different
individuals, and in the same individual under different circumstances

(Jenkins, 1966).

Saliva is mainly composed of water (99.5%) (Best and Taylor, 1961).

Besides water, saliva contains protein (0.3%), inorganic constituents

including calcium, phosphorus, sodium, potassium, fluoride, chlorine,
magnesium, phosphate, and bicarbonate; and dissolved gases including
nitrogen, oxygen and carbon dioxide (Jenkins, 1966; Roth and Calmes,
1981). The protein content of human saliva consists of mucoides,
enzymes, amino acids, albumin, globulin, urea and ammonia (Jenkins,
1966). Saliva composition is affected by many factors: rate of saliva
secretion, age and sex, time of the day, nature of stimulus, composition of

diet, hormones, fatigue and race (Jenkins, 1966; Roth and Calmes, 1981).

Unstimulated saliva has a pH of 6.75 (5.6 — 7.6) (Jenkins, 1966; Spector,
1956) and a specific gravity that varies from 1.002 to 1.008 (Best and
Taylor, 1961). Kerr (1961) stated that specific gravity increases with
increase in rate of flow. The relative viscosities at the stimulated state,
reported as Newtonian fluids, for the three major secretions at the room
temperature are as follows: parotid 1.5 cp, submandibular 3.4 cp, and
sublingual 13.4 cp (Jenkins, 1966). The viscosity of the mixed saliva
tends to fall if left to stand for an hour, which has been attributed to the
depolymerization of mucoids by the bacterial proteolytic enzymes

present in the saliva. However, during the time when there is a fall in

viscosity, very little change in protein concentration has been observed

(Jenkins, 1966).

Grant et a1. (1979) reported that the flow rate under stimulated conditions
from the parotid gland is 0.7 ml/min and from submandibular gland is 0.6
ml/min. The rate of saliva secretion under the basal conditions is 0.5
ml/min and under the sour taste conditions ranges from 5.0 to 8.0 ml/min
with the total volume of saliva secreted in a 24-hour period ranging from
800 to 1500 ml (Moore, 1980). The maximum secretion from a gland is
also dependent on the weight of the gland with an average rate of 1 ml /
mg weight of the gland in one minute (Johnson, 1998; Beme and Levy,

1983).

Mixing of saliva and food in the mouth initiates the digestion process and
saliva plays a major role in bringing about desirable changes in the food
after ingestion. The major enzyme in saliva is the salivary amylase
(called ptyalin), which leads to the breakdown of starch into maltose in
the mouth. It might play an active role when mixed with food products
but is inactivated once the food bolus reaches the stomach because of the

acidic conditions (pH <4) found there. Other enzymes present in saliva

include lipase, aldolase, lysozyme, esterase and peroxidase (Jenkins,
1966). Lipase might be an enzyme of concern in high fat foods such as
mayonnaise. Salivary lipase has low activity since the conditions
prevailing in mouth are not favorable for the salivary lipase to be active.
Jenkins (1966) stated that salivary amylase is the only enzyme that is
sufficiently active in the mouth to play a significant part in breakdown of

the food constituents in mouth.

2.1.2 Oral Cavity

Oral cavity, or the mouth, is bounded by lips, cheeks, palate and the floor
of the mouth, all of which participate in modifying the food ingested. In
addition, gingivae, teeth and tongue all contribute to changes in the bolus.
Kuroda et a1. (1996) found the size of oral cavity to be 61.15 cubic cm
and the surface area of the palate to be 30.22 square cm. Davenport
(1966) reported the amount of bolus swallowed at a time as 5 — 15 cubic
cm, while Logemann reported the bolus size as 7 — 10 cubic cm
(information received through personal communication with Dr. Sonies).
Logemann reported that along with the bolus, 1 — 2 ml saliva is also
swallowed (Manual for the Videofluorographic Study of Swallowing, 2nd

edition).

Logemann found that the tongue depth is normally 5 — 6 cm, and when at
rest, it fills the whole oral cavity (information obtained through personal
communication with Dr. Sonies) and while swallowing, it squeezes the
food into the pharynx. Pressure exerted by tongue depends on the
viscosity of food material, and an increase in bolus consistency
significantly increases the amplitude of lingual pressure (Shaker et a1.,
1988; Smith et a1., 1997). Pressure applied by lips varies from O to 90
mm Hg as stated by (Shaker et a1., 1988). They also found that pressure
amplitude is related to the consistency of food but is not correlated with
the volume of food. Miller and Watkin (1996) reported that the volume

of the bolus does not significantly influence the force amplitude.

When the food is ingested, teeth break the solid materials down to small
particles of few cubic millimeters that can be easily swallowed and
digested (Johnson, 1998; Davenport, 1966). During mastication, the food
is comminuted and lubricated with saliva simultaneously. Each chewing
cycle lasts for 0.5 — 1.2 sec (Roth and Calmes, 1981). Hiiemae (1999)
confirmed that the average time for which the bolus resides in the mouth
is 7.5 sec. While in the mouth, food is subjected to the squeezing forces

of the tongue, palate and checks, and crushing forces of teeth. The biting

lO

forces developed on a tooth as reported by Roth and Calmes (1981), may
range from 20 — 200 kg and the force generated on molar teeth can be 5 —
10 kg. Ruch and Patton reported biting forces of 11 — 25 kg due to the
incisor teeth. Liquids with viscosities typical of soups and sauces

experience shear rates of approximately 50 sec'1 (Wood et a1., 1973).

2.2 Mayonnaise and Miracle Whip
Mayonnaise is used as a spread in conjunction with the salads, breads and
other foods. It is an oil — in — water emulsion in which oil (dispersed
phase) is dispersed in water (continuous phase) and forms a space —
filling structure that gives consistency to the fluids. For any emulsion, the
lower the fat content, the higher would be the aqueous phase. The size of
droplets ranges from 1 pm to 5 pm (Rosenthal, 1999) and determine the
amount of oil that can be dispersed in the continuous phase (water). A
wider range of droplet size distribution gives a higher amount of oil
dispersed in the water. The droplets of dispersed phase determine the
properties of mayonnaise. Certain undesirable processes, like creaming,
flocculating and coalescence lead to changes in the physical condition
resulting in changes in the rheological behavior. To avoid these physical

changes, an emulsifier like egg yolk or gum is added to reduce the

11

interfacial tension to only a few mPa m instead of 30 mPa m (Rosenthal,
1999) between oil and water thus stabilizing the emulsion. Emulsifiers

are also used to increase viscosity in light mayonnaise.

Regular mayonnaise, unlike low fat mayonnaise, has an oil concentration
of about 70 — 80% (Rao, 1999). It is a stable emulsion with complex
viscoelastic rheological behavior. The emulsion undergoes structural
rearrangements to impart properties like yield stress, pseudoplasticity and
time — dependent behavior to the mayonnaise (Peressini et al. 1998,
Plucinski et a1. 1998); hence, it is a non — Newtonian fluid whose shear
viscosity decreases with increase in shear rate. Its viscous nature is
determined by the volume fraction (quantity of fat drops present) of the
dispersed drops. At a low volume fraction, viscosity of the emulsion
increases with the amount of dispersed phase; at an intermediate volume
fraction, a nonlinear relationship exists between viscosity and the amount
of dispersed phase; and at a high volume fraction, the emulsions exhibit

plastic behavior rather than viscous behavior.

The viscoelastic nature of mayonnaise is attributed to the deformability

of the fat drops present in the emulsion (amount of fat drops present in

any emulsion is represented by the volume fraction). As long as the
applied stresses are below the stresses produced during the
homogenization process, deformation of fat drops is negligible.
Therefore, emulsions at intermediate volume fraction behave as viscous
fluids during handling and eating. In emulsions with high volume
fraction (high amount of fat in the emulsion), individual fat drop is
surrounded by other fat drops and so the motion of fat drops is possible
only when the neighboring drops deform sufficiently to make space for
the fat droplet to move. Hence, flow occurs at stress high enough to
deform the fat drops. Thus the emulsions with high concentrations of fat

have significant yield stresses.

The yield stress of traditional full — fat mayonnaise has been reported to
be 50 Pa (Rosenthal, 1999) and the yield stress decreases with the
decrease in oil content (Peressini et a1., 1998). The structure of
mayonnaise comprises a close network of lipids and proteins with the oil
droplets entangled within the network. Peressini et a1., 1998 asserted that
this compact packing of oil drops in the lipoproteic network is

responsible for the deformation resistance and resilient properties of the

13

emulsion. The network formed defies the effect of force applied and

hence, provides the elastic characteristic to the mayonnaise.

Researchers have reported presence of wall slip while collecting
measurements using the rotational viscometers, thus rendering some
conventional viscometers ineffective for rheological measurements of
mayonnaise even at very low shear rates (10'3 sec") (Plucinski et a1.,

1998).

In a product such as Miracle Whip, which has a high amount of starch or
carbohydrates, action of salivary amylase might be a probable factor in
product breakdown. Also, it can be assumed that there are no significant
chemical changes in the fat or oil present in the food ingested. Since a
product such as mayonnaise is an oil in water emulsion, there are no
major changes in the chemical composition; however, there are
significant changes in the physical composition of the mayonnaise (and
also in Miracle Whip) due to the incorporation of large amount of water

from saliva.

l4

2.3 Mixer Viscometer Constant (k’)

The mixer viscometer constant is an entity that converts the angular
velocity into shear rate. It is a unique value that differs depending on the
impeller being used and is determined from experimental data. It is a
factor that depends on the geometry of the impeller and has been shown
to be influenced by the flow behavior index (n) and angular velocity (N)
(Castell — Perez and Steffe, 1990 and Mackey et a1., 1987). Similar
studies have been conducted in the past with different impellers to find
the value of k’. For a flag impeller the value of k’was found to be 20.1
rev" in a Brookfield small sample adaptor by Briggs and Steffe, 1996; for
a star impeller, k’ was reported to be 19.7 rev"l by Rao and Cooley
(1984); for a pitched paddle impeller, the corresponding value was found

to be 28 rev’I in a Haake MVl cup (Ford and Steffe, 1986).

15

CHAPTER 3

THEORETICAL DEVELOPMENT

An impeller must be calibrated prior to being used for conducting
experiments, so that the instrumental data obtained can be utilized to gain
information about the food material being tested. To standardize an impeller,
two constants, mixer coefficient (k ”) and the mixer viscometer constant (k ’),
must be calculated. The calculation of these constants involves various
assumptions and mathematical relationships as described in the subsequent

sections.

3.1 Flow Regime During Mixing and k ”
The flow regime can be characterized by the impeller Reynolds number
(NR6. ,), which corresponds to the ratio of the inertial force to the opposing
viscous force in a Newtonian fluid during mixing. The numerical value of
NR8) indicates if the flow is laminar, transitional or the turbulent during
mixing. At NR8) values less than 10, laminar flow exists in the system and
at values above 10,000, a turbulent flow is present when the angular
velocity is expressed in units of rev/sec. At a value between 10 and

10,000, transitional flow is present. If the value for angular velocity is

16

expressed as rad/sec, the corresponding values for NR8) are 63 and

63,000, respectively. The impeller Reynolds number is defined as

_,0Nd2

N Re,I
,u

[3.1]

Under the laminar flow regime, the mixing power number (Npo) and
impeller Reynolds number (NR9, ,) involved in mixing of Newtonian fluids

are related by the following equation (Metzner and Otto, 195 7):

 

A
N =
o .2
P NRe,I [3 ]

where A is a constant, which depends on the system geometry and the

 

 

N _ P de 2
flow regime. Substitution of P0 '— ,0 N 3 d 5 and N ReJ : T in
Eq. [3.2] yields,

P : A,u
pN3d5 dez [3.3]

Eq. [3.3] was rewritten by Mackey et al. (1987) as

N x1
M = —
k" [3.4]
,, N #
or k = _M [3.5]

17

where k" = 1/ (Ad 3) rev/m3. The value of the parameters can be
determined from experimental data as the inverse of the slope of the plot
between torque and the product of angular velocity and viscosity as also
indicated by Eq [3.5]. k” is a constant that depends only on the
dimensions of the impeller and cup; hence, it is a unique value for every

system.

3.2 Mixer Viscometer Constant, k ’
k’is the mixer viscometer constant expressed in units of l/rad or l/rev. It
has a unique value for a particular mixing system that depends on the
geometry of the system and the flow regime. The constant is required to
convert angular velocity into average shear rate. It can be determined by
two methods: slope method and matching viscosity method. In this study,

the matching viscosity method was utilized to evaluate k’.

Using the “matching viscosity” assumption, which states that when the
viscosity of Newtonian fluid is equivalent to the apparent viscosity of the
non — Newtonian fluid, the average shear rate of a non — Newtonian fluid

is equal to the average shear rate of the Newtonian fluid (Steffe, 1996).

18

Based on this assrnnption, Newtonian viscosity or apparent viscosity (in

case of non—Newtonian fluids) is related to the average shear rate as,

. n~1
y=n=K(7.) [3.61
Equating the Newtonian viscosity, defined for the case of laminar

mixing, by Eq. [3.4], Eq. [3.6] may be written as,
n M . n-l
k 7V = K021) [3.7]

According to Metzner and Otto (1957), the average shear rate is linearly
proportional to the impeller rotational speed when the mixing regime is
laminar. The proportionality constant is called mixer viscometer constant
(k ’). Thus, the relation between average shear rate and angular velocity is

depicted as
h=FN an
Substitution of Eq. [3.8] into Eq. [3.7] gives the mathematical

relationship between k ’ and k ",

l

k,_ 1 Mk" 271
"" 37 KN [3.9]

 

19

CHAPTER 4

MATERIALS AND METHODS

4.1 Experimental Equipment
Experiments were conducted using Haake VT 550 rotational viscometer
(Haake USA, Paramus, NJ) that has a maximum torque capacity of 3 N
cm (Fig. 4.1). Two systems were used for testing: 1) The MVl concentric
cylinder (Fig. 4.2) with 4.0 cm and 4.2 cm as internal and external
diameters, respectively, and 2) The helical ribbon and MVl cup (Fig.
4.3) with 3.3 cm and 4.2 cm internal and external diameters, respectively,
and 3.40 cm impeller height. Fig. 4.4 illustrates the complete dimensions
of the helical ribbon that was manufactured from 304 stainless steel. The
helical ribbon was attached to the Haake VT 550 using a Haake flag
adapter. The viscometer was interfaced with Haake RheoWin Job
Manager software for control and data acquisition. Data were analyzed

using Microsoft Excel.

During testing, sample temperatures were maintained at 5° C
(refiigeration temperature) or 21° C (room temperature), or 37° C (body

temperature), with a variation of i 0.5° C. The temperatures were

20

 

 

Fig. 4.1 Haake VT 550 Rotational Viscometer

21

 

Fig 4.2 MV 1 Concentric Cylinder System

22

 

 

Fig 4.3 Helical Ribbon and Cylinder System

23

 

 

 

 

 

 

    

 

 

 

 

 

 

 

 

 

 

 

h

, E are
.. -3 .1
d dJi

L

F D ’1 Ch

 

where: C = clearance between impeller and cup (0.30 cm)
Cb: clearance between bottom and impeller (0.8 cm)
D = cup diameter (4.20 cm)
d = impeller diameter (3.30 cm)
h = impeller height (3.40 cm)
H = height of sample in cup (4.2 cm)
p = pitch (1.70 cm)
W = blade width of ribbon (0.50 cm)

Fig 4.4. Complete dimensions for helical ribbon and sample
cup

24

maintained using a Haake F6 / C25 water bath. When required, Cole —
Parmer® 74900 — Series Multi-channel Syringe Pump (Cole — Parmer
Instrument Company, IL) (Fig. 4.5) was used to add de — ionized water

into the sample.

4.2 Characterization of Helical Ribbon
The helical ribbon was characterized by determining the values of the
mixer coefficient (k”) and mixer viscometer constant (k’), which are

unique for the system used in this study. The value for each constant was

found from experimental data.

4.2.1 Determination of k ”

Glycerin (Columbus Chemical Industries, Inc., Columbus, WI) and
silicon oil (Brookfield Engineering, Stoughton, MA), with varying
viscosities (Table 4.1), were used for the determination of k”. These
materials are standard Newtonian fluids that have a linear relationship

between shear stress and shear rate.

The value of k” was determined using the Torque Curve Method

(Mackey etal, 1987 ). All the experiments were conducted in laminar

25

 

Fig 4.5 Multi — Channel Syringe pump

26

Table 4.1: Newtonian fluids used with the helical ribbon impeller to

 

 

evaluate k ’
Fluid Viscosity (Pa 5)

Silicon Oil 0.490
(Brookfield Engineering, Stoughton, MA)

Glycerin 0.740
(Columbus Chemical Industries, Inc., Columbus, WI)

Silicon Oil 5.20
(Brookfield Engineering, Stoughton, MA)

Silicon Oil 5.28

(Brookfield Engineering, Stoughton, MA)

 

27

flow region defined by the magnitude of the impeller Reynolds number
Eq. [3.1]: (MM) < 10, when angular velocity is expressed in units of
rev/s. The respective ranges of angular velocities calculated and used

during the experiments are listed in Table 4.2

The fluid density used in determining the angular velocity range was

calculated as:

,0 — _ [4.1]

Prior to running experiments, the fluid was loaded in the cylinder and
allowed to sit undisturbed for 30 min to equilibrate to the desired
temperature. The experiments were conducted using the helical ribbon at
an angular velocity range to ensure the laminar flow. Raw data between
torque (M), angular velocity (N) and viscosity (u) were obtained.
Employing linear regression, the slope of the linear curve (defined by Eq.

3.4) was obtained and the inverse of this slope yielded the value of k ”.

28

Table 4.2. Range of angular velocity (rpm) for Newtonian Fluids with

different viscosities as calculated using the Reynolds number

 

 

Viscosity (Pa 5) Angular velocity range (rpm)
0.49 10 — 40
0.74 5 — 50
5.20 50 — 450
5.28 50 — 450

 

29

4.2.2 Determination of k ’

Non-Newtonian fluids including guar gum (Sigma Chemical Company)
and hydroxypropyl methyl — cellulose (HPMC) (A4M PREM) (The Dow
Chemical Company) were employed at different concentrations to obtain
the value of k’. Guar gum and HPMC were available in the powdered
form and 1.00%, 1.50%, 2.00%, 2.25% and 2.50% (weight basis)
solutions of both were made by dissolving them in warm, deionized
water. While mixing the powders in the water, care was taken to avoid
incorporation of air bubbles into the solution. The powder was added
evenly and in small quantities at a time, and mixing was carried out
slowly and carefully. Solutions were allowed to sit overnight to allow the

complete hydration of the powder.

The experiments to determine k’ were then conducted on the above
solutions at room temperature (21°C _+_ 0.5 °C) using both the helical
ribbon and cylinder systems. Solutions were loaded and allowed to sit for
approximately 30 minutes to attain the equilibrium temperature. Using a

similar angular velocity range as used during the determination of k”, the

raw data with angular velocity ([2) and torque (M) were obtained.

30

Employing the raw data for the concentric cylinder system, shear stress

and shear rate were calculated using the following equations:

 

_ M
a 7 27: 1212,} [43]
. dz
.7=29[a2_,] [AM

A curve was obtained between shear rate and stress for each solution.
Employing regression analysis, the values for consistency coefficient (K)
and flow behavior index (n) were obtained for each non -— Newtonian

solution (Table 4.3) based on the power law model:
0=KW ”a

Using these values of K and n, the values of k’were calculated with the

helical ribbon data from Eq. [3.9]:
1
k! -1 . W
N KN

With these calculated values of k’, curves were obtained between k’

 

values and the respective angular velocities for each solution. From the

curves, 3 single and constant value was obtained to represent each fluid.

Table 4.3: Non - Newtonian fluids used with the helical ribbon impeller to
evaluate the value of k ’

 

 

Product K (Pa 3") n (-)

2.50% Guar Gum 122 0.14
2.25% Guar Gum 72.0 0.24
2.00% Guar Gum 76.9 0.19
1.50% Guar Gum 28.0 0.27
1.00% Guar Gum 6.66 0.39
2.50% Methyl Cellulose 11.4 0.64
2.25% Methyl Cellulose 6.76 0.62
2.00% Methyl Cellulose 5.95 0.73
1.50% Methyl Cellulose 1.22 0.79
1.00% Methyl Cellulose 0.33 0.85

 

32

Using these individual constant values of k’(obtained at high speeds) for
all the solutions, a curve was plotted between the k’ values and flow
behavior indices. Linear regression established a relationship between k’

and n. The resulting equation was used to calculate the values of k’for
different food products having different flow behavior indices when

being tested for rheological properties using the helical ribbon.

4.3 Evaluation of Helical Ribbon
The helical ribbon system was assessed and its performance was
compared to a traditional concentric cylinder viscometer. Food products
used to evaluate the helical ribbon were Heinz tomato ketchup (H. J.
Heinz Co.), French’s mustard (Reckitt & Colman Inc.) and Henri’s
classic Southwest ranch dressing (Henri’s Food Products Co.). Ketchup
and mustard are homogenous products but Henri’s ranch dressing is a
non-homogenous product and was found to contain particles up to 4mm

length.

Experiments were conducted at the room temperature (21°C at 0.5 °C)

with the Haake MVl concentric cylinder system at shear rate range of 1 —

50 l/sec for 60 sec. The raw data obtained contained values for shear

33

rate, stress and apparent viscosity. A curve was plotted between shear
rate and stress and a power law regression model (Eq. [4.6]) was
evaluated to obtain the value of flow behavior index (n) for all the foods
tested. Using the respective values of n and the relationship between k’
and flow behavior index (n) (Sec 4.2.2), the values of k’were calculated
for the respective food products. With the calculated values of k’, as

obtained above, the range of angular velocity (N) at shear rate range of l

- 50 1/sec for each food product was calculated using the Eq. [4.7]:

_ Z.
N _ kt [4.7]

Using the appropriate range of angular velocities, experiments were
conducted at the room temperature (21°C i 0.5 °C) on the fresh food
products using the helical ribbon system. Raw data were torque (M) and
angular velocity (N). Using this information, the shear rate (7) and
apparent viscosity (7;) values were calculated using Eq. [4.7] and [4.8],

respectively,

77=k

,, M
7 [4.8]

After conducting similar experiments on the fresh food product samples

with the shear rate range input of l — 50 l/sec using the concentric

34

cylinder system, resulting rheograms were compared to those obtained
with the helical ribbon data. Each food product was evaluated three times
and the average of the three data sets for individual food products was

taken to compile the result.

4.4 Evaluation of Physical Changes in Food Emulsions with Addition of
Water
Kraft Fat — Free Mayonnaise, Kraft Light Mayonnaise, Kraft Real
Mayonnaise, Kraft Miracle Whip and Hellmann’s Real Mayonnaise
were used to evaluate the effect of water addition on the flow behavior
of emulsions. These materials were taken from the 32 — oz jars of the
same lot for all the replications. Table 4.4 lists the major ingredients in
these products. De-ionized water was used in all experiments. The
experimental set up was scaled — up seventeen times to emulate the
conditions existing in the mouth (Table 4.5), which included the
volume of sample and water, water flow rate, running time of
experiment, and shear rate that matched the volume of bolus and saliva,
saliva flow rate, residence time, and shear rate in the oral cavity, based
on the published literature. These variations gave the proportional

increase to instrumentally meet the conditions of the oral cavity. The

35

Table 4.4 Major ingredients present in the five food products

 

Food Product

Major Ingredients

 

Kraft Fat Free Mayonnaise

Kraft Light Mayonnaise

Kraft Real Mayonnaise

Kraft Miracle Whip

Hellmann’s Real Mayonnaise

Water, modified food starch, high
fructose corn syrup

Water, modified food starch, egg

yolks, soybean oil

Water, egg yolks, soybean oil

Water, starch, egg yolks, soybean oil

Water, egg yolks, whole eggs,

soybean oil

 

36

 

Table 4.5 Scaled — up numerical values used during the experiments to

meet the conditions existing in the oral cavity

 

 

Conditions Oral Cavity* Sample Scale
Volume (ml) 3.0 51.2 1 : 17
Residence time (s) 7.5 127.5 1 :17
Water Flow Rate (ml/min) 4.0 4.0 l : 1
Water Volume (ml) 0.5 8.5 1 : l7

 

* The values for the oral cavity were based on the published literature

37

impeller was completely immersed and was in level with the sample.

Water addition was carried out using two methods: without manual
mixing (using a syringe pump) and with manual mixing (mixing by
hand). When not mixed manually, the product’s rheological behavior
can be studied before, during and after the incorporation of water.
Occasionally, undesirable results were encountered with this mixing

method, which led to the introduction of the manual mixing method.

In the manual mixing method, the changes occurring during
incorporation of water could not be studied as water was added prior to
experimentation. Rheological properties before and after mixing of

water were determined.

4.4.1 With Automatic Water Injection
The whole data set consisted of a set of three tests as described below.
In all the tests, the sample was loaded and kept for about half an hour

before running the test so that the sample attained the equilibrium

temperature of 21°C 2% 05°C.

38

Lest_1 .° A pre — shear test was conducted on each sample with the
concentric cylinder system at the shear rate of 25 1/sec for 60 sec.
Following this, another test was carried out on the same sample with the
same system over the shear rate range of l — 50 l/sec in 60 sec period.
With the raw data, a rheogram was plotted between shear rate and
stress. By employing the power law regression model, the values for the
flow behavior index (n) and consistency coefficient (K) were obtained.

Using the linear relationship between flow behavior index (n) and k’
(Sec. 4.2.2), the value for k’was found for the respective food product.

Using this value of k’, the value of angular velocity (N) was derived

using Eq. [4.7] at shear rates 1.25 l/sec and 2.5 l/sec.

M: To observe the changes brought about in the food product
during the mixing of water, a test was conducted on a fresh food
product sample of 52-ml. The helical ribbon system was employed and
the test was carried out at the angular velocity calculated in Test 1 and
de — ionized water was injected into the system through a multi-channel
syringe pump at a rate of 4 ml/min and the total volume of water added

was 8.5 m1. Total running time for each experiment conducted was

39

 

127.5 sec. Data obtained were saved for further analysis and the sample

was further used to conduct Test 3 as described below.

M The sample obtained above was used to run another experiment
with concentric cylinder system at the shear rate range of 1 — 50 l/sec
for 60 sec (similar to Test 1). Using the raw data, a rheogram was
obtained between shear rate and stress. With the use of power law, the
values for flow behavior index (n) and consistency coefficient (K) were
evaluated. Comparison of these values to that of the corresponding
values obtained prior to addition of water (Test 1) indicates the changes

brought about from the addition of water.

Tests 1, 2 and 3 indicate the rheological properties of the food product
before, during and after addition of water, respectively. The same data
sets were collected at three temperatures: refiigeration temperature
(5°C), room temperature (21°C), and body temperature (37°C). Four
replications of the above tests were conducted in a similar manner at

each temperature with each food product.

40

4.4.2 With Manual Mixing

One complete data set under this method of water addition consisted of
four tests as elaborated below. All the tests were conducted at 21°C i
05°C. Required range of angular velocities (N) was obtained by using
the Eq. [4.7]. The value of k’to be used in this equation was obtained
by taking an average of the k ’ values obtained while conducting Test 1,

Sec 4.4.1, for all the products at all temperatures.

22911: A test was conducted using the helical ribbon on a fresh 52 -— ml
food sample within the range of angular velocity at average shear rates
of l to 50 l/sec (as calculated using the Eq. [4.7]) for 60 sec. During the
test, both ramp up and ramp down variations were conducted to check
for thixotropic behavior of the food product. From the raw data of

torque (M) and angular velocity (N), the shear rates ( 7) and apparent

viscosity ( 72,) were calculated using the Eq. [4.7] and Eq. [4.8]

respectively for all the data points.

Test 2: The next test was similar to Test 1 but prior to running the

experiment, 2.125 ml of water was added to the fresh food sample of 52

41

ml and was manually mixed. This sample was used to conduct an
experiment under similar conditions as for Test 1 and was followed by

similar calculations.

Test 3: In this test 4.25 ml water was added to a 52 ml fresh food
sample and mixed manually prior to carrying out the experiment. The
test was conducted in a similar manner as was conducted under Test 1,

and shear rate and apparent viscosity were calculated.

Test 4: A fresh sample of 52 ml was taken and 8.5 ml water was added
and mixed manually. Then the experiment was carried out as in Test 1

followed by calculation of shear rate and apparent viscosity.

With the data obtained in Tests 1, 2, 3, and 4, a graph was plotted
between average shear rate and apparent viscosity for the food samples
with different amounts of water incorporated. Employing the power law
(Eq. [4.6]), a relationship was obtained between apparent viscosity and
shear rate for each sample. With the equations obtained, the apparent
viscosities were calculated at shear rates 1, 25 and 50 l/sec and a graph

was plotted with apparent viscosity and the ratio of water incorporated

42

 

4.5

in the sample to maximum water incorporated (i.e., 8.5 ml) in the
sample at all the three shear rates. Thus, three curves were obtained on
the same graph for one food product that would correspond to the three
shear rates.

Using the manual mixing method, three temperatures were considered
for the tests, refrigeration temperature (5°C), room temperature (21°C),
and body temperature (37°C) to observe the effect of temperature on the
product at different level of water incorporation. Each food product was
evaluated at three temperatures in a similar manner to obtain four

replicates.

Evaluation of Kraft Miracle Whip with Different Textural
Properties

Five types of Kraft Miracle Whip (obtained directly from Kraft),
varying slightly in their textural properties, were evaluated with the
helical ribbon to measure structural differences instrumentally. Five
samples (labeled 219, 221, 234, 240 — 1, and 240 — 2) were tested at
room temperature (21°C) applying the “with manual mixing” analogy
as described under Section 4.4.2. The following textural specifications

for the samples were provided by Kraft: 219 was soft, gel type of body

43

that would give a creamy mouth feel after the application of shear in the
mouth; 221 was reported to be lumpy that would undergo fast
breakdown; 234 sample was a light textured miracle whip with slightly
lumpy body; samples 240 - l and 240 2 were similar with thick body,
and good cling to the mouth, sample 240 — 2 was also reported to have

a good body.

44

CHAPTER 5

RESULTS AND DISCUSSION

5.1 Characterization of the Helical Ribbon
The helical ribbon impeller was characterized by determining various
constants that can be utilized to evaluate the rheological properties of
different food products. The viscometer coefficient (k ”) and the mixer
viscometer constant (k’) are the major parameters involved in the
analysis of the data obtained by conducting experiments with helical

nbbon.

5.1.1 Evaluation of k ”

Viscometer coefficient (k ”) is the constant that is solely dependent on
the geometry of the impeller and thus is a unique value for a particular
impeller. Figure 5.1 depicts the plot obtained for the determination of
k”. The experiments were conducted at room temperature (21° C i 0.5
°C) using the Newtonian fluids (silicon oil and glycerin). The data
obtained for the standards at different viscosities were pooled together

to obtain a curve between torque and the product of angular velocity

and viscosity. By inserting the linear trend line, the slope of the curve

45

Torque (N m)

0.03

0.025

0.02 .

P
c
I—t
UI

 

y = 0.0006127x
R2 = 0.97

0.01
k"= 1 I 0.0006127

=1632 rev/m3
0.005 s

10 20 30 40 50

Angular velocity * Viscosity (Pa rev)

Figure 5.1 Plot obtained for the determination of k" using
Newtonian fluids

46

(defined by Eq. 3.4) was found to be 0.0006127, the inverse of which

yielded the value ofk”as 1632 rev/m3.

Since the Newtonian fluids used during the evaluation of k” had
different viscosities (Table 4.1), the ranges of angular velocities used
while conducting the experiment were different (Table 4.2). This
range was based on the Reynolds number and was calculated using
the Eq. 3.1 to ensure a laminar flow in the sample. The angular
velocity range was found to be lower for the standards with lower
viscosity, which in turn gave the data sets in the different regions of
the graph. Thus, the data were pooled to obtain one value of k”
representing the helical ribbon for all the food materials irrespective

of their viscosities.

5.1.2 Evaluation of k ’
In addition to the value of k”, the value of K and n are also required to
determine the value of k’at different angular velocities using the Eq.

3.9. To find K and n, plots (Fig. 5.2 and 5.3) were obtained for stress

(Pa) and shear rate(l/sec) for non—Newtonian fluids, guar gum

47

Stress (Pa)

200 _,,-+-- A.” [1 ‘r h
‘ ”v.7. .. -.
o 9“ "'7 i
‘. o I“ .'f# "
.. ‘1 .-. .2 cage 0 O o - 2.50/0GG
o - fl. .1
.0. 0 +7 2.250/0 GG
.
150 ‘ g ‘ 2.00/0 CG
0 M‘ 1.50/0 GG
x l-oo/oGG
a
O
100 _
l
“gee-Jr-t -8 8 iv 8 -1“ g -3
x ‘4 ' 's x r
x: x
. x
o
50 . ,
7*. X X ~X~r X ..*_ X- a: X79 *"*~~~x~~ ~~X~~x
‘ .x-‘ or»): * i
x
0. ._
0 20 40 60 30 100 120

Shear rate (1/sec)

Figure 5.2 K and n values for guar gum at different
concentrations

48

Stress (pa)

200

150

50

O p .-

{\1 i

a!»

{a

2.5% HPMC

2.00/0 HPMC X’-
2.25o/o HPMC /‘
1.5% HPMC ‘
1.0% HPMC -
,.A""
,A"
A ‘
n ‘
.A'
. ’
'- /... ,. . ‘.
,1 .1
‘ I ”,9
r- /‘fi
. /‘ ‘
I ‘ g .
A ,c
O“
' 0
‘ /./I
/ ’l/'
A y
0’ a“;
. D" .n. D II
nee—4P4? ..n-
own It
//nflw
4r
”fin/u 0 “4*"’ 'O 0970'"? O O o o
.,.,. c o c o c
20 40 60 80 100

Shear rate (l/sec)

Figure 5.3 K and n values for HPMC at different

cOncentrations

49

120

and HPMC at different concentrations. By using the power law
regression model, the values of K and n were obtained for each fluid
(Table 4.2). It can be observed from the table that the value of K
increases with the increase in the concentration of the solution
indicating the increasing thickness of the fluid. The values of n, on the
other hand, show the opposite trend, which decreases with the
increase in the concentration of the solution, with the exception of

2.25% guar gum and 2.5 % HPMC.

With the known values of k”, K and n, the values of k’were calculated
and were plotted against angular velocity (Fig 5.4 and 5.5). From
these curves it can be seen that the values of k’ are a function of
angular velocity and were found to decrease sharply as the angular
velocity increased from O to 0.1 rev/sec for both the guar gum and

HPMC solutions. The guar gum solutions acquired a constant value
for k’ at the angular velocity of 0.2 rev/sec at all the concentrations
except for the 1.0 % guar gum solution, which attained a constant

value at the angular velocity of 0.1 rev/sec. From the curves obtained,
a constant and an average value of k’ was obtained for each non —

Newtonian solution and thus a range of k’values was obtained after

50

25

23

21»

19

17~

k' (l/rev)

11 \

0 0.1 0.2 0.3 0.4

+10% CC
-—2.5% GG
—t—2.25% CG
+ 1.5% GG
—x— 1.0% CC

0.5 0.6

Angular Velocity (rev/sec)

Figure 5.4 k' at different angular velocities for Guar Gum at

different concentratiOns

51

k' (1/rev)

25

20

15

10

+ 2.25% HPMC
—+— 2.5% HPMC
+1.5% HPMC

+10% HPMC

 

 

 

 

0.1 0.2 0.3 0.4 0.5 0.6

Angular Velocity (rev/sec)

Figure 5.5 k' at different angular velocities for HPMC at
different concentrations

52

pooling all the constant values attained for all the solutions (thus, 10
constant values for k? as 3 — 11 l/rev. Value of the constant for any
solution would be within this range. Also, it can be seen that the
values of k’decreased with the decrease in the concentration in each
fluid. Hence the constant was found to be a variable entity depending

on the experimental set up.

Besides changing with the angular velocity, the value of k’was also
found to vary with the flow behavior index (n). It decreases with the
increase in n meaning that as the concentration and the viscosity of the
fluid decrease, the value of k’also decreases. However, this trend was
not seen in the 2.0% GG and 2.50% HPMC solution. The relationship
between k’and the n is depicted in the Fig. 5 .6 with the actual values
given in Table 5.1. From this curve, it is evident that k’ and n are
linearly related to each other and hence, on application of the linear
regression, an equation can be obtained relating the two entities.
Using this equation, the value of k ’was calculated using the value of n
for the food products tested using the helical ribbon. The equation
obtained was

k’ =-11.486n+ 11.521

53

12

10

k' (1/rev)
Ox

. y=-11.486x+11.521
R2 = 0.8654

 

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Flow Behavior Index (-)

Figure 5.6 Mixer viscometer constant (k') and flow
behavior index (n) for guar gum and HPMC at different
concentraitons

54

Table 5.1 Values of flow behavior index (n) and mixer viscometer constant

(k 9 for guar gum (GG) and HPM C at different concentrations

 

 

Non — Newtonian fluid n k' (l/rev)
2.50 % GG 0.136 9.0
2.25 % GG 0.244 8.4
2.00 % GG 0.198 10.4
1.50 °/o GG 0.271 8.0
1.00 % CC 0.392 7.0
2.50 % HPMC 0.642 4.0
2.25 % HPMC 0.623 6.4
2.00 % HPMC 0.727 3.2
1.50 % HPMC 0.797 1.0

1.00 % HPMC 0.849 1.8

 

55

5.2 Evaluation of the Helical Ribbon
The performance of the helical ribbon was evaluated and compared to
the performance of a traditional concentric cylinder viscometer. The
comparison of rheograms (Fig. 5.7) indicates that curves acquired by
both the systems show similar trends. The curves obtained for the
ketchup and mustard by the two systems are very close to each other,
which indicates that the helical ribbon reveals similar results as the
concentric cylinder. However, some differences are seen in the curves
of Henri’s Ranch dressing and this trend is also observed by comparing
the values of consistency coefficient and flow behavior index (Table

5.2).

The rheograms for the three food products can be compared by
considering the values of consistency coefficient (K) and flow behavior
index (n) for the respective curves (Table 5.2). The values for K and n
are very close for ketchup and mustard and the greatest variation is
revealed for the Henri’s Ranch dressing. Ketchup and mustard are
homogenous food materials while the Henri’s Ranch dressing is a non —

homogenous food material. The variation in the values of Henri’s

Ranch dressing might be attributed to the presence of large (size S4

56

Apparent Viscosity (Pas)

14

+ Henris ranch MVl

+ Henri's Ranch HR
+ Ketchup MVl
—-x— Ketchup HR

+ Mustard MV 1
+ Mustard HR

 

10 20 30 40 50 60
Shear Rate (l/sec)
Figure 5.7 Rheograms of different food products comparing
results from Haake Concentric Cylinder (MVl) and Helical
Ribbon (HR) systems

57

Table 5.2 Comparison of consistency coefficient (K) and shear — thinning
indices (n) for typical food products as obtained with helical

ribbon and concentric cylinder systems

 

 

 

Food Product Helical Ribbon Haake VT 550
K n K n
(Pa 8") (-) (Pa 8") (-)
Henri’s Ranch 1.312 0.482 24.90 0.285

Henri’s Food Products Co., Inc. Milwaukee, WI

Ketchup 25.97 0.226 24.38 0.212
H. J. Heinz Co. Pittsburgh, PA

Mustard 28.91 0.253 24.12 0.306
Reckitt & Colman Inc., Wyne, NJ

 

58

mm) particles in the dressing, which might lead to variable results with
the concentric cylinder. Since the particle size is large as compared to
the clearance between the concentric cylinder and the bob, the torque
response during the experiment might be erroneous. In experiments
with the helical ribbon, on the other hand, particles have enough space
to move around the sensor, which also helps keep the particles in
suspension. Hence, the helical ribbon is more reliable than traditional
sensors and can be effective sensor measuring the rheological properties
of the non — homogenous food products with a significant yield stress

or large particles.

5.3 Evaluation of Physical Changes in Food Products with Addition of
Water During Mixing
Food products behaved differently under the two analogies (automatic
vs. manual addition of water) and demonstrated various structural
changes with water that were visually apparent with automatic water
addition. In this case, Kraft Fat Free Mayonnaise showed an even
mixing of water but the sample had a rough texture, very loose body
and small pieces of mayonnaise separating from the bulk. In the Kraft

Light Mayonnaise sample, water was fully incorporated in the sample

59

but it became lumpy, and structural disintegration into small clumps
was observed. Upon completion of the experiment, the sample had a
coarse texture. Kraft Real Mayonnaise incorporated a significant
amount of water into the structure initially, but did not easily
incorporate water to a large extent and by the end of the experiment; a
thin water layer could be seen on top of the sample, which looked
smooth after the addition of the water. In the case of Kraft Miracle
Whip, even mixing of water was observed and a creamy mixture with
smooth texture and slightly cloudy liquid at the periphery was obtained.
Hellmann’s Real Mayonnaise behaved in a similar manner. Initially
with the addition of water, a uniform, smooth mixture without the
separated and distinguished layer of liquid water, and solid mayonnaise
was obtained. As the experiment proceeded, a smooth solid mixture and
slight cloudy liquid at the periphery was produced, and ultimately, a

uniform liquid mixture was obtained.

In context, manual mixing of water into the sample produced a uniform
material in every case. Final samples were smooth and creamy and
differences in the body were not observed. The mixing was more

uniform.

60

5.3.1 Automatic Water Injection

Satisfactory mixing with the helical ribbon was only obtained for some
products at some temperatures. Kraft Light Mayonnaise at 37 °C, Kraft
Real Mayonnaise at 21°C and 37 °C, and Hellmann’s Real Mayonnaise
at 37 °C did not give satisfactory results with this method. Mixing was
not homogenous which led to separate water and mayonnaise layers.
Mayonnaise tended to stick to the central shaft of the helical ribbon,
which prevented the water from being incorporated in the sample.

Alternative impellers are needed to overcome this problem.

Figures 5.8 through 5.12 compare the behavior of Kraft Fat Free, Kraft
Light Mayonnaise, Kraft Real Mayonnaise, Kraft Miracle Whip, and
Hellmann’s Real Mayonnaise, respectively, at three temperatures, 5°C,
21°C, and 37°C with 8.5 ml water added at the rate of 4.0 ml/min. The
data were compiled by running four replications for each experiment
and the average of the four runs was considered for the analysis. Using
the raw data for angular velocity, shear rate was calculated using Eq.
3.8, which was plotted against apparent viscosity as strain history (shear
rate * time). From all the curves a general trend can be observed in the

behavior of the food products: the apparent viscosity decreases with

61

Apparent Visocsity (Pas)

90 ~

80

70

60

50

4o .—

30

20

10

o
o
OSC(SR1.25)
, l21C(SR2.5)
A37C (SR 1.25) ‘
o
I o
. o
o
I o
o
A
I
‘ I o
A I .
A - . . O . .
A l o
A o
A I 0
A
A I I
A l I
A I I
A A I
‘ A . I I
‘ A
A
A
20 40 60 80 100 120 140 160 180

Strain History (-)

Fig 5.8 Kraft Fat Free at different temperatures during the
addition of 8.5 ml water at the rate of 4.0 ml/min
(with automatic addition of water)

62

Apparent Visocsity (Pas)

140

120

100

80

60

40.

20

o
o
o .5C(SR1.25)
o .21C(SR2.5)
o
o
o
o o , .
o
o
' o
I o
’ o
’ o
I
I
I
I
I
I
I I I I
0 20 40 60 80 100 120 140 160 180

Strain History (-)

Fig 5.9 Kraft Light Mayonnaise at different temperatures during the
addition of 8.5 ml water at the rate of 4.0 ml/min
(with automatic addition of water)

63

Apparent Visocsity (Pas)

140 ,

o o 5 C (SR 1.25)

120

100 9

80

60 O O

40 9

20»

0. ., , L, L, L A L, a L 5.x, z
0 20 40 60 80 100 120 140 160 180

Strain History (-)

Fig 5.10 Kraft Real Mayonnaise at 5 C during the addition of
8.5 ml water at the rate of 4.0 ml/min
(without manual mixing)

64

140

120

100

80

60

Apparent Visocsity (Pas)

40—

20

9 , z
o OSC(SR1.25)
. l21C(SR2.5)
9199“ 13,5)
9
o
A
A o
A
A
o
A
o
‘ o
I o
I 8 o
I o
‘ . . ’ o o
o
I
A
A I
A I
A
A ‘ F
A
An A
‘I A
20 40 60 80 l 00 120 140 160 180

Strain History (-)

Fig 5.11 Kraft Miracle Whip at different temperatures uring the
addition of 8.5 ml water at the rate of 4.0 ml/min
(with automatic addition of water)

65

120

100

80

Apparent Visocsity (Pas)

40

20.

. 5 C(SR 1.25)

60,

o
.21C(SR2.S)
o , ,_ ,
o
o
o
I .
I
I
I
o
I
I
o
. o
I o
I O
I
I. . I
I . .0. I I
o .-
o
o
O 20 40 60 80 100 120 140 160 180

Strain History (-)
Fig 5.12 Hellmanns Real Mayonnaise at different temperatures during

the addition of 8.5 ml water at the rate of 4.0 ml/min
(with automatic addition of water)

66

increase in the strain history during water addition.

The experiments at 5°C were conducted at 1.25 l/sec shear rate for all the
food samples. However, the experiments for the samples at 21°C did not
give the appropriate mixing; hence, they were conducted at 2.5 l/sec
shear rate except for the Kraft Fat Free Mayonnaise, which performed
well at the lower shear rate. At body temperature, experiments were
conducted satisfactorily at the lower shear rate. This variation of shear
rates resulted from the inadequate mixing of water in the sample at the

lower shear rate for some food products.

Comparison of behavior of the Kraft Fat Free Mayonnaise at three
different temperatures (Fig 5.8) indicates that the sample was thickest at
the refrigeration temperature (5°C) and thinnest at the body temperature
(3 7°C) throughout the experiment. The difference in apparent viscosities
at the three temperatures for Kraft Fat Free Mayonnaise was significantly

lower than the difference observed for other food samples.

67

Fig 5.9 illustrates the behavior of Kraft Light Mayonnaise at different
temperatures. At 5°C, the sample was found to be significantly thicker as
compared to the sample at 21°C. Experiments for Kraft Real Mayonnaise
sample could be conducted only at 5°C, since it did not incorporate water
properly at 21°C and 37°C at any shear rate considered (1.25 and 2.5
l/sec. Fig 5.1 1 depicts the behavior of Kraft Miracle Whip, which shows
an initial fall in the apparent viscosity at 5°C, conducted at 1.25 l/sec
shear rate, that later attains an almost constant value. The samples at
21°C and 37°C were found to attain a similar apparent viscosity at the
completion of the experiment although the sample at 37°C started at a
higher apparent viscosity value. In case of Hellmann’s Real Mayonnaise
(Fig 5.12) the sample at 5°C had the higher apparent viscosity at the
beginning of the experiment but had the lower apparent viscosity at the
end when compared to the sample at 21°C. The experiments could not be

evaluated at 37°C at any shear rate because of inadequate mixing.

Figures 5.13 through 5.15 compare rheological properties of the five food
products at three temperatures. At 5°C, Kraft Light Mayonnaise showed

the thickest texture (Fig 5.13) throughout the experiment and had a very

68

Apparent Viscosity (Pa 5)

140

120

100

80

60

40

20

OKrafi Fat free
. x IKraft Light mayo
I x AKraft Real Mayo
I
Ix x Kraft Miracle Whip
X x x Hellmanns real mayo
I
X
I
A
X X .
x I I I .
A I
o I
Q X
I
O x I
O A x . I
o ‘ I I
A A
X X o x
O X A
O .X
X ‘X . . . .
‘x x x x . o
X
x A x 0x x
A
X
X
X
x
x x
X
X
X
20 40 60 80 100 120 140 160 180

Strain History (-)

Fig 5.13 Food products at 5 C at 1.25 l/sec shear rate during the
addition of 8.5 ml water at 4 ml/min
(with automatic addition of water)

69

Apparent Viscosity (Pa 5)

90

80

70

60

50

40

30

20

10

0 Kraft Fat free I

I Kraft Light mayo

x Kraft Miracle Whip

x Hellmanns real mayo 1

I
I
o
o
x
x
I
o
X o
I
X o
X X 9
o
x I
o
o
x O o .
I O
x x x . o
o
x I . .
X ' I I
X x X I
x {E x x
x x x
x
x
20 40 60 80 100 120 140 160 180
Strain History (-)

Fig 5.14 Food products at 21 C at 2.5 l/sec shear rateduring the

addition of 8.5 ml water at 4.0 ml/min
(with automatic addition of water)

70

Apparent Viscosity (Pa 5)

100

90

80

70

60

50

40,

30

20

10

o Kraft Fat free
x . .
x Kraft Miracle Whip
x ,i , ,,
x
x
x
o
. x
o
o
o
. x
o
O
o
o
x o
9 O
x 8 o
x . o
X o
x o
x
x
x
x x x
x

20 40 60 80 100 120 140 160

Strain History (-)
Fig 5.15 Food products at 37 C at 1.25 l/sec shear rate during the

addition of 8.5 ml water at 4.0 ml/min
(with automatic addition of water)

71

180

low rate of viscosity change. Kraft Fat Free Mayonnaise had the lowest
apparent viscosity before the experiment but Hellmann’s Real
Mayonnaise showed the lowest viscosity at the end of the experiments,
which was also seen to thin out the maximum amount during the
experiment going from 110 Pas to 2 Pa 8 with the highest rate of viscosity
change. Kraft Real Mayonnaise showed a high rate of viscosity change
and thinned out significantly during the experiment. Before testing, it had
the highest viscosity along with Kraft Light Mayonnaise. Kraft Fat Free
Mayonnaise shows the least effect of water addition on its consistency,
and has the minimum rate of change in its apparent viscosity. Kraft
Miracle Whip also showed significant textural changes with a moderate
rate of viscosity change. At this temperature water mixed into all the

samples satisfactorily.

At 21°C (Fig 5.14), Kraft Light Mayonnaise showed the highest apparent
viscosity at the beginning of the experiment, but Kraft Fat Free
Mayonnaise had a higher viscosity at the end. Kraft Fat Free Mayonnaise
showed the minimum effect of the water addition on the apparent
viscosity. Data for Kraft Real Mayonnaise could not be collected because

of the inappropriate mixing. A general trend of decreasing apparent

72

viscosity with increasing strain history was observed in all the food
products though the apparent viscosity tended to attain a constant value.
Kraft Fat Free Mayonnaise, Kraft Miracle whip, and Hellmann’s Real
Mayonnaise showed similar amount of change in the viscosity and
showed approximately the same rate of viscosity change. Kraft Light

Mayonnaise had the highest rate of change of viscosity at 21°C.

Fig 5.15 depicts the behavior of food products at the body temperature
(37°C). Kraft Miracle Whip had the higher apparent viscosity initially,
but after testing it had the lower apparent viscosity; it showed the
maximum change in the textural properties due to the addition of water.
Kraft Fat Free Mayonnaise showed an almost constant drop in the
viscosity throughout the experiment; however Kraft Miracle Whip
showed a drastic change in the viscosity at the beginning but the rate of
change of viscosity decreased later. The results obtained at this
temperature for Kraft Light Mayonnaise, Kraft Real Mayonnaise and
Hellmann’s Real Mayonnaise were not reliable as the samples were
found to be sticking to the helical ribbon that inhibited proper mixing of

water in the sample. The experiments for these products were conducted

73

using the concentric cylinder analogy instead of the helical ribbon

calculations to determine shear rate.

5.3.2 Manual Mixing of Water

This analogy to human mastication involved manual incorporation of
water into the sample before conducting the experiments; therefore, it did
allow evaluation of changes occurring in the sample during mixing of the
water. Using manual mixing method, the structural composition of the
food samples was studied after different volumes of water were added to
the sample. Comparisons were made by studying the change of apparent
viscosity with respect to the ratio of volume of water added to the sample
(Vw = 0, 1.25, 2.5, and 8.5 m1) divided by the maximum volume of water
added (Vm = 8.5 ml). The mixing speed was calculated using a constant

value of k’equal to 8.64 l/rev.

In general, it was seen that as the ratio of Vw / Vm approached 1, the
apparent viscosity decreased. The apparent viscosities at a shear rate of 1
l/sec were significantly higher than the viscosities at shear rates of 25
and 50 l/sec for all the food samples at all the temperatures. There was a

significant drop in viscosity at the beginning of each experiment. Little

74

change in the viscosity was observed between 25 and 50 l/sec shear rate
at all temperatures for all food products. The highest viscosities were
found at the refrigeration temperature at all the shear rates, followed (as

expected) by the viscosities at room temperature and body temperature.

Figures 5.16 through 5.20 compare the changes in the apparent viscosity
with respect to Vw / Vrn for the food products individually, at three
temperatures, at l l/sec shear rate for different levels of water added to
the sample. Fig 5.16 depicts the plot for Kraft Fat Free Mayonnaise,
which indicates maximum overall change in the apparent viscosity at the
refiigeration temperature. The result obtained at 5°C at 0 level water for
the Kraft Fat Free Mayonnaise is not reliable because the sample was
seen sticking to the helical ribbon. Unexpectedly, the apparent viscosity
at 37°C at the maximum water level (Fig 5.16) was recorded to be
highest. Not much difference was observed at 37°C at the 2.125 and 4.25
ml water levels. The sample showed significant change in the structure at
5°C and 21°C, though not much variation was observed at the body
temperature. Kraft Light Mayonnaise (Fig 5.17) behaved as expected.

The highest viscosities were recorded at 5°C, followed by 21°C and

37°C. The data point at 5°C withO ml water was unreliable since the

75

Apparent Viscosities (Pa 5)

120 I

100

80

60

40

20

O Shear Rate 1 l/sec 5 C
I Shear rate 1 1/sec 21 C

8 A Shear Rate 1 l/sec 37 C
. O
A A
' A
O
I
0.2 0.4 0.6 0.8 1 1.2
Vw/V m

Fig 5.16 Kraft Fat Free Mayonnaise at three temperatures at 1
1/sec shear rate
(manual mixing)

76

Apparent Viscosities (Pa 5)

180

160

140

120 I

100

80

60

40

207

O Shear Rate 1 l/sec 5 C
I Shear rate 1 l/sec 21 C
1A Shear Rate 1 l/sec 37 C

O
. O
A
I
A O
I
A
0.2 0.4 0.6 0.8 l
Vw/Vm

Fig 5.17 Kraft Light Mayonnaise at three temperatures at 1
1/sec shear rate
(manual mixing)

77

1.2

Apparent Viscosities (Pa 5)

180

160

140

120

100

W
O

ON
G

40

20

>

O Sir—car Rate 1 l/sec 5 C
I Shear rate 1 l/sec 21 C
A Shear Rate 1 l/sec 37 C

o

O

I

A
O
I
A

0.2 0.4 0.6 0.8 1 1.2
Vw/V m

Fig 5.18 Kraft Real Mayonnaise at three temperatures at 1
1/sec shear rate
(manual mixing)

78

Apparent Viscosities (Pa s)

140

120

100

80

60

40

20

o Shear Rate 1 l/sec 5 C
I Shear rate 1 l/sec 21 C
A Shear Rate 1 l/sec 37 C ,

O
A
I
A
I
O
A
I
0.2 0.4 0.6 0.8 l

Vw/V m

Fig 5.19 Kraft Miracle Whip at three temperatures at three
Shear rates
(manual mixing)

79

1.2

Apparent Viscosity (Pa s)

180 o

‘9 Shear Rate 1 l/sec 5 C
I Shear rate 1 l/sec 21 C
A Shear Rate 1 l/sec 37 C

160

140

120
A

100

80 9

ID

40
20

0 0.2 0.4 0.6 0.8 1 1.2

Vw/V m

Fig 5.20 Hellmanns Real Mayonnaise at three temperatures
at 1 1/sec shear rate
(manual mixing)

80

sample stuck to the impeller leading to a flawed result. The maximum
change in the consistency was observed at refrigeration temperature and
minimum at body temperature. Kraft Real Mayonnaise (Fig 5.18) showed
the expected trend at all temperatures and water levels, with maximum
changes occurring at the refrigeration temperature and minimum at the

body temperature.

Fig 5.19 illustrates the plot obtained for the Kraft Miracle Whip, which
showed a similar trend to the Kraft Real Mayonnaise. Little difference
was observed between the viscosities at room temperature and body
temperature at all the water levels. The viscosities for all samples with

8.5 ml water were found to be similar.

Hellmann’s Real Mayonnaise (Fig 5.20) showed a higher viscosity at
37°C than at 21°C except at 4.25 ml water level where the sample at
21°C had a higher viscosity, but the viscosities were close at all water
levels at room temperature and body temperature. As with other
materials, the maximum overall change in apparent viscosity was

observed at refrigeration temperature.

81

Figures 5.21 through 5.25 display the plots obtained for all the food
products at a shear rate of 25 l/sec. Apparent viscosities recorded at 25
l/sec were significantly lower than those at 1 l/sec for all the products at
all the temperatures. Kraft Fat Free (Fig 5.21) shows tremendous change
in the viscosity at 5°C and 21°C, but not much change was observed at
37°C. Viscosity was highest at refiigeration temperature as expected. The
data at 5°C with 0 level water was not reliable due to the inadequate
mixing. Kraft Light Mayonnaise (Fig. 5.22) behaved in a similar way as
the Kraft Fat Free did at 25 l/sec but there was a significant change in the
apparent viscosity at 37°C. A similar trend was shown by the Kraft Real
Mayonnaise samples (Fig. 5.23) with significant changes in the apparent
viscosity at all temperatures. Kraft Miracle Whip (Fig 5.24) and
Hellmann’s Real Mayonnaise (Fig 5.25) followed the pattern but showed
little difference in the apparent viscosities at room temperature and body

temperature.

Related plots for food products at 50 l/sec are shown in the Figures 5.26
through 5.30. All products followed the expected trend with higher
viscosities at the refrigeration temperature and lower viscosities at body

temperature. The data points for Kraft Fat Free Mayonnaise (Fig 5.26)

82

Apparent Viscosities (Pa s)

14

12

10

0.2

0.4

0.6
Vw/V m

x Shear Rate 25 l/sec 5 C
x Shear rate 25 l/sec 21 C
I Shear Rate 251/sec 37 C

0.8 l 1.2

Fig 5.21 Kraft Fat Free Mayonnaise at three temperatures at 25
1/sec shear rate
(manual mixing)

83

Apparent Viscosities (Pa 5)

14

12

10

x Shear Rate 25 l/sec 5 C
x Shear rate 25 l/sec 21 C
I Shear Rate 25 l/sec 37 C

x
x
x
x
o x
o
x
o
0.2 0.4 0.6 0.8 1 1.2

Vw/V m
Fig 5.22 Kraft Light Mayonnaise at three temperatures at 25

l/sec shear rate
(manual mixing)

84

Apparent Viscosities (Pa s)

14*

12

10

x Shear Rate 25 Used 5 C
x Shear rate 25 l/sec 21 C
I Shear Rate 25 l/sec 37 C

X
X
X
I
X
' x
I
0.2 0.4 0.6 0.8 1 1.2
Vw/V m
Fig 5.23 Kraft Real Mayo at three temperatures at 25 1/sec
shear rate

(manual mixing)

85

Apparent Viscosities (Pa 8)

10

_,__,,..._. ____*.;.._:..1. _

x Shear Rate 25 l/sec 5 C
x Shear rate 25 l/sec 21 C
O Shear Rate 25 l/sec 37 C

x
x
l
x
x
o
x
o
0.2 0.4 0.6 0.8 1 1.2

Vw/V m

Fig 5.25 Hellmann's Real Mayonnaise at three temperatures at
25 l/sec shear rate
(manual mixing)

87

Apparent Viscosities (Pa S)

10

5+ Shear Rate 50—1A/sec 5 C I
l - Shear Rate 50 l/sec 21 C
- Shear Rate 50 l/sec 37 C

0.2 0.4 0.6 0.8 l 1.2
Vw/V m

Fig 5.26 Kraft Fat Free Mayonnaise at three temperatures at 50
1/sec shear rate
(manual mixing)

88

Apparent Viscosities (Pa 5)

10 —-

+ Shar—Ratefi50 l/seTS C r
9 ! - Shear Rate 50 l/sec 21 C
- Shear Rate 50 l/sec 37 C

Vw/Vm

Fig 5.27 Kraft Light Mayonnaise at three temperatures at 50
l/sec shear rate
(manual mixing)

89

Apparent Viscosity (Pa 5)

10

+Shear Rate 50fisec 5C
- Shear Rate 50 l/sec 21 C
- Shear Rate 50 l/sec 37 C

0.2 0.4 0.6 0.8 1 1.2

Vw/V m
Fig 5.28 Kraft Real Mayonnaise at three temperatures at 50
1/sec shear rate
(manual mixing)

90

Apparent Viscosity (Pa 5)

10

I Shari} s‘o NEE—5 E
- Shear Rate 50 l/sec 21 C
- Shear Rate 50 l/sec 37 C

l

0.2 0.4 0.6 0.8 1 1.2
Vw/Vm

Fig 5.29 Kraft Miracle Whip at three temperatures at 50 l/sec
shear rate
(manual mixing)

91

Apparent Viscosity (Pa 5)

10 ,,_,,

+Shear Rate 50 l/sec 5 C
- Shear Rate 50 l/sec 21 C
- Shear Rate 50 l/sec 37 C

 

0 0.2 0.4 0.6 0.8 1 1.2

Vw/V m
Fig 5.30 Hellmanns Real Mayonnaise at three temperatures at
50 1/sec shear rate
(manual mixing)

92

and Kraft Light Mayonnaise (Fig. 5.27) at 5°C at 0 ml water in the
sample could not be collected because the sample stuck to the ribbon
which prevented proper mixing. Not much variation was shown by Kraft
Fat Free Mayonnaise (Fig. 5.26) at 37°C with the increased water, though
there was a significant difference between the apparent viscosities at
different temperatures. Kraft Light Mayonnaise showed similar behavior,
as the Kraft Fat Free Mayonnaise. Both samples underwent significant
textural changes with different water levels at 50 l/sec. Kraft Light
Mayonnaise had significant change at 37°C, unlike Kraft Fat Free
Mayonnaise, though not much change was observed between the sample
with 0 ml water and the sample with 2.125 ml water, but with further
addition of water, the viscosity changed significantly. The patterns for
Kraft Real Mayonnaise (Fig. 5.28), Kraft Miracle Whip (Fig. 5.29), and
Hellmann’s Real Mayonnaise (Fig. 5.30) followed Kraft Light
Mayonnaise. The change in the viscosities at all the temperatures was not
as much as that observed with Kraft Light Mayonnaise. Plots for
Hellmann’s Real Mayonnaise at 21°C and 37°C were very close

indicating very minor difference in the texture at the two temperatures.

93

On comparing the plots obtained at different shear rates for a product, it
can be observed that the Kraft Fat Free Mayonnaise and Kraft Light
Mayonnaise had lower viscosities at 25 l/sec at 37°C than the viscosities
of the samples at 50 l/sec at 5°C and 21°C. The data points obtained for
Kraft Real Mayonnaise at 50 l/sec at 5°C and 25 l/sec at 37°C were
found to be similar. For Hellmann’s Real Mayonnaise it was observed
that initially during the experiment, the viscosities at 25 l/sec at 37°C
were higher than the viscosities at 50 l/sec at 5°C, but at the end of the

experiment, the viscosities at body temperature were found to be lower

than the viscosities at refrigeration temperature.

Figures 5.31 through 5.33 are the plots obtained for all the food products
at three temperatures at 25 l/sec. Kraft Light Mayonnaise was found to
have the highest consistency at all temperatures and underwent the
maximum change in the apparent viscosity. At 5°C (Fig. 5.31), Kraft Fat
Free Mayonnaise did not show a big difference with added water, and the
change in viscosity was minor between the sample without water and the
sample with 8.5 ml water. A rise in apparent viscosity was observed in
the sample with 1.25 ml water compared to the sample without water,

which might be attributed to the presence of starch in the mayonnaise.

94

Apparent Viscosity (Pa 5)

14 A

   
  

o KFF
i I KLM ;
l A KRM ;
12 I x KMW
o HRM
A
10 _
y - -6.9817x + 9.8145 y = -6.8129x +1343
X R2 = 0.9663 R2 = 09934
O
3 .
X
6 3
o A
y = -1.3843x + 5.7968 . \
R2 = 0.8253
4
y = -5_0234x + 7.824 i<= -5.6497x + 9.0505
R2 = 0.9682 3 R2 = 0.9531
2
0 0.2 0.4 0.6 0.8 l 1.2
Vw/V m

Fig 5.31 All food products at 5 C at shear rate 25 l/sec
(manual mixing)

95

Apparent Viscosity (Pa s)

4K6}:
I IKLM
{AKRMI
IxKMW
:oHRM~

  
  
  
  
   

y = -5.9571x + 10.605
R2 = 0.9697

   

y = -2.6091x + 6.0207
R2 = 0.8139

y = 4.4109x + 7.0135
, R2 = 0.9906

y = -3.3617x + 5.1545

R’- = 0.9859
y - 47871x + 7.2275
R2 = 0.984
0 0.2 0.4 0.6 0.8 l 1.2
Vw/V m

Fig 5.32 All food products at 21 C at shear rate 25 1/sec
(manual mixing)

96

Apparent Viscosity (Pa 5)

OKFF

I KLM ‘
l A KRM ‘
x KMW 1
I r
1 o HRM .
I
X
A y = -3.9871x + 7.455
R2 = 0.9828
0
‘ = -1.176x + 4.632
R2 = 0.9853
y = -3.2626x + 4.668
R2 = 09389 y = -4.0111x + 6.258
O x R2 = 0.9744 '
y = 4.1803x + 5.822
A R2 = 0.9791
0.2 0.4 0.6 0.8 1 1.2

Vw/V m
Fig 5.33 All food products at 37 C at shear rate 25 l/sec
( manual mixing)

97

Starch absorbs water and swells leading to an increase in apparent
viscosity. Kraft Light Mayonnaise showed the highest apparent viscosity
at all water levels. Kraft Real Mayonnaise had a thicker consistency in
the beginning but in the sample with 8.5 ml water, they had similar
viscosities. Kraft Miracle Whip showed lower decrease in apparent
viscosity than the Kraft Real Mayonnaise, and was found to be thicker

than Kraft Real Mayonnaise at the end of the experiment.

At 21°C (Fig. 5.32), Hellmann’s Real Mayonnaise had the lowest
apparent viscosity in all tests. Kraft Fat Free, Kraft Real Mayonnaise, and
Kraft Miracle Whip had similar viscosities at 1.25 and 2.5 ml water level
while at 0 and 8.5 ml, the viscosity for Kraft Fat Free was slightly
different from the rest of the two samples. Kraft Light Mayonnaise, at
this temperature behaved normally and the experiment could also be
conducted satisfactorily without addition of water. The sample had the

thickest consistency at all the water levels.

At 37°C (Fig. 5.33), Hellmann’s Real Mayonnaise showed the thinnest
texture at all water levels except for the pure sample where the Kraft Fat

Free had the lowest apparent viscosity. Kraft Fat Free Mayonnaise

98

changed little in texture during experimentation; however, Kraft Real
Mayonnaise and Kraft Miracle Whip underwent significant changes in

lCXtUI'C.

Tables 5.3 through 5.5 show the linear slopes obtained for different food
products at three temperatures. Through these tables, the change in
viscosity can be studied and correlated to the behavior of the product.
Some products were seen to break down faster than the others. At all the
temperatures, Kraft Fat Free Mayonnaise had the minimum slope and
underwent minimum change in the apparent viscosity with addition of
water. It absorbs water and maintains consistency throughout the
experiment. Kraft Real Mayonnaise shows the maximum slope except at
21°C at which Kraft Light Mayonnaise had the maximum change in
apparent viscosity. At other temperatures, Kraft Light Mayonnaise
closely followed Kraft Real Mayonnaise. At 5°C (Table 5.3), Kraft
Miracle whip and Hellmann’s Real Mayonnaise followed Kraft Real
Mayonnaise and Kraft Light Mayonnaise. At 21°C (Table 5.4), Kraft
Light Mayonnaise underwent maximum change in consistency that was
followed by Kraft Miracle Whip, Kraft Real Mayonnaise, and

Hellmann’s Real Mayonnaise. At 37°C ( Table 5.5 ), Kraft Real

99

Table 5.3 Slopes obtained for all food products at 5 °C at 25 I/sec

 

 

Products Slope (Pa 8) R1
KFF - l .38 0.82
KLM -6.81 0.99
KRM -6.98 0.97
KMW -5.65 0.95
HRM -5.02 0.97

 

100

Table 5.4 Slopes obtained for all food products at 21 °C at 25 I/sec

 

 

Products Slope (Pa s) R1
KFF -2.60 0.81
KLM -5.97 0.97
KRM -4.41 0.99

KMW -4.79 0.98

HRM -3.36 0.98

 

101

Table 5.5 Slopes obtained for all food products at 3 7 °C at 25 1/sec

 

 

Products Slope (Pa s) R2
KFF -l .17 0.98
KLM -3.98 0.98
KRM -4.18 0.97

KMW -4.01 0.97

HRM -3.26 0.94

 

102

Mayonnaise was followed by Kraft Miracle Whip, Kraft Light

Mayonnaise, and Hellmann’s Real Mayonnaise.

The manual mixing analogy worked satisfactorily with all products and
gave important insight into the textural properties after mixing water in
the sample. The analogy has been proven to work satisfactorily with
emulsions and would be helpful for other semi fluid, yield stress
possessing food products on which conducting experiments has been
difficult. The mastication analogy, involving the automatic addition of
water produced some unsatisfactory results. Manual mixing generated
superior results and seems to be a method with excellent potential for

evaluating the mastication of fluid foods.

5.4 Analysis of Kraft Miracle Whip with different textural
characteristics
The helical ribbon was used to study the textural differences
instrumentally in different Kraft Miracle Whip samples subjected to
partial sensory evaluation. Manual mixing analogy to mastication was

employed since it was proven to be effective for studying the minor

103

Apparent Viscosity (Pa 5)

o KMW 219
7 ° - KMW 221
" A KMW 234
: x KMW 240 1
6 l; o KMW 240 2
I
O
X
5 A
I
4 t
O
X
I
3
2
1
0 . _ _ _
0 0.2 0.4 0.6 0.8 1 1.2
Vw/Vm

Fig 5.34 All Miracle Whip samples at 21 C at shear rate 25 l/sec
(manual mixing)

104

differences in the products. Fig 5.34 shows the plot obtained for the five
types of Miracle Whip tested. All the samples show a similar trend with
minor differences in the rate of change in apparent viscosity with water.
Sample numbered 219 was reported by Kraft to have a soft texture,
which would give a creamy texture in the mouth after the shear
application. Sample 221 was lumpy and underwent fast breakdown with
the addition of water. Sample 234 had a slightly lumpy appearance with
light texture. The sample numbered 240 — 1 was relatively thick, firm,
not in the gelled form, and was stated to have good cling in the mouth.
Sample 240 — 2 was similar to 240 — 1 and had a good body. From the
plot, it can be seen that sample 221 maintained the lowest apparent
viscosity and had the softest texture among all the samples. Samples
numbered 240 (1 and 2) had a similar rate of change of viscosity but 240
— 1 had a softer texture. These samples exhibited the highest rate of
viscosity change. Sample numbered 219 had the minimum change in the

viscosity and showed the minimum rate of change in viscosity.

105

CHAPTER 6

CONCLUSIONS AND SUMMARY

The helical ribbon impeller was characterized by determining the value of
the mixer coefficient (k’) as 1632 rev/m3, and the range of the mixer
viscometer constant (k’) as 3 — ll l/rev. The impeller was seen to be an
effective tool in studying the rheological properties of food products when
results obtained were compared to those found through conventional

viscometry.

The change in the viscosities in emulsions like mayonnaise (with varying
amount of fat present) and Miracle Whip were studied using automatic
incorporation or manual mixing of water. Manual mixing proved to be
superior in differentiating products and can be strongly recommended for
further studies. Results obtained may be utilized to study the effect of fat
replacers on the mouth feel of emulsions. The helical ribbon viscometer has

a potential as a mastication emulator.

Water addition had a significant effect on the consistency of the emulsions

with the apparent viscosity falling considerably with the addition of water.

106

The extent of decreasing viscosity and overall emulsion behavior were
influenced by the presence of the fat replacer. Kraft Fat Free Mayonnaise
proved to be the most stable product showing minimal change in the
consistency with added water. The influence of temperature was also evident
on all the products as the data obtained for the viscosities at higher
temperature were lower than the viscosities obtained at lower temperature.
With all factors considered, Kraft Light Mayonnaise was found to have the
thickest consistency. Thus the impeller can be satisfactorily utilized in

studying the effects of varying ingredients on product flow behavior.

107

CHAPTER 7

RECOMMENDATIONS FOR FUTURE STUDIES

1n the light of current work on the helical ribbon impeller, the following

topics are suggested for further research:

1. Utilizing the impeller to study other food products that have large sized

particles or a significant yield stress.

2. Studying the effect of new fat replacers and other ingredients on the
textural properties of the Mayonnaises and Miracle whips with the helical

fibbon.

3. Correlate the results obtained by instrumental evaluation to the sensory

panel analysis to identify the desirable texture for a product.

4. Utilizing the manual addition of water to other food products to study

structural modifications occurring simultaneously with the increase in

water level and change in temperature.

108

APPENDIX

109

Table A.l. Data for silicon oil with viscosity 0.490 cp used during the
determination of k”:

 

Silicone oil (Viscosity = 0.490 cp)

 

M (Nm) N (rpm) N (r138) N *n (Pa ReV)
0.00007 9.903 0.1650 0.0808
0.00008 13.20 0.2200 0.1078
0.00010 16.60 0.2766 0.1355
0.00013 20.00 0.3333 0.1633
0.00014 23.30 0.3883 0.1902
0.00017 26.60 0.4433 0.2172
0.00019 29.90 0.4983 0.2441
0.00021 33.20 0.5533 0.2711
0.00023 36.60 0.6100 0.2989
0.00025 39.90 0.6650 0.3258

 

Table A.2. Data for glycerin with viscosity 0.740 cp used during the
determination of k”:

 

Glycerin (Viscosity = 0.740 cp)

 

M (Nm) N (rpm) N (rps) N*n (Pa rev)
0.00002 4.899 0.0816 0.0604
0.00010 9.998 0.1666 0.1233
0.00016 15.00 0.2500 0.1850
0.00022 20.00 0.3333 0.2466
0.00026 25.00 0.4166 0.3083
0.00031 30.10 0.5016 0.3712
0.00037 35.00 0.5833 0.4316
0.00042 40.10 0.6683 0.4945
0.00048 45.20 0.7533 0.5574
0.00053 49.70 0.8283 0.6129

 

110

Table A.3. Data for silicon oil with viscosity 5.20 cp used during the
determination of k ”:

 

Silicone oil (Viscosity = 5.20 cp)

 

M (N m) N (rpm) N (rps) N*n (Pa rev)
0.0015 49.90 0.831 4.324
0.0051 94.90 1.581 8.224
0.0084 139.5 2.325 12.09
0.0120 184.7 3.078 16.00
0.0131 230.1 3.835 19.94
0.0145 272.9 4.548 23.65
0.0162 318.3 5.305 27.58
0.0176 361.3 6.021 31.31
0.0183 405.4 6.756 35.13
0.0195 449.6 7.493 38.96

 

Table A.4. Data for silicon oil with viscosity 5.30 cp used during the
determination of k ”:

 

Silicon Oil (Viscosity = 5.28)

 

M (Nm) N (rpm) N (rps) N *V (Pa rev)
0.0015 49.90 0.831 4.441
0.0063 94.10 1.568 8.374
0.0101 138.9 2.315 12.36
0.0135 184.4 3.073 16.41
0.0148 228.4 3.806 20.32
0.0172 272.1 4.535 24.21
0.0195 317.5 5.291 28.25
0.0207 361.1 6.018 32.13
0.0222 407.8 6.796 36.29
0.0242 448.8 7.480 39.94

 

111

Table A.5 Data for the determination of h ”using the Newtonian fluids:

 

 

Angular Velocity * Viscosity (Pa s) Torque (Nm)
0.060 0.0001
0.123 0.0001
0.185 0.0001
0.246 0.0002
0.308 0.0002
0.371 0.0003
0.431 0.0003
0.494 0.0004
0.557 0.0004
0.612 0.0005
4.324 0.0015
8.224 0.0051
12.09 0.0084
16.00 0.0120
19.94 0.0131
23.65 0.0145
27.58 0.0162
31.31 0.0176
35.13 0.0183
38.96 0.0195
0.080 0.0001
0.107 0.0001
0.135 0.0001
0.163 0.0001
0.190 0.0001
0.217 0.0002
0.244 0.0001
0.271 0.0002
0.298 0.0002
0.325 0.0002
4.441 0.0015
8.374 0.0063
12.36 0.0101
16.41 0.0135
20.32 0.0148
24.21 0.0172
28.25 0.0195
32.13 0.0207
36.29 0.0222
39.94 0.0242

 

112

Table A.6 Data sets for K and n values for guar gum at different

 

 

 

 

 

concentrations
1.0% CO 1.5% CO
Stress (Pa) Shear rate (l/sec) Stress (Pa) Shear rate (1/sec)
4.928 0.939 22.21 0.939
16.10 6.794 50.26 6.549
20.83 12.40 61.63 12.40
24.37 18.26 69.71 18.01
24.83 21.99 72.07 21.77
26.87 27.62 75.29 27.62
28.38 33.46 77.72 33.23
29.76 39.09 79.5 39.09
30.22 42.82 80.55 42.82
31.14 48.68 81.01 48.68
32.19 54.29 82.39 54.29
32.78 60.14 84.10 59.92
33.44 63.90 85.08 63.65
33.84 69.51 85.74 69.51
34.3 75.36 86.59 75.14
35.02 80.97 87.18 80.97
35.48 84.73 88.04 84.73
36.00 90.58 88.56 90.34
36.66 96.19 89.55 96.19
36.99 99.95 90.01 99.95
2.0% CO 2.25% GG
Stress (Pa) Shear rate (1/sec) Stress (Pa) Shear rate (1/sec)
62.22 0.939 54.99 0.939
118.8 6.549 127.3 6.549
143.3 12.4 154.3 12.4
151.6 18.01 166.4 18.26
156.8 21.99 172.4 21.99
160 27.62 177.8 27.62
164 33.23 181.4 33.46
166.1 39.09 184.7 39.09
166.2 42.82 187.5 42.82
168.3 48.45 189.3 48.68
170 54.29 190.9 54.29
169.4 59.92 194.4 60.14

 

113

 

 

 

 

 

114

170.2 63.65 195.4 63.9
173.1 69.51 195.7 69.51
174.2 75.14 197.2 75.36
175.4 80.97 198.2 79.12
176.1 84.73 200 84.95
176.5 90.34 201.2 90.58
177.3 96.19 202.4 96.19
177.8 99.95 202.6 99.95
2.5% CO
Stress (Pa) Shear rate (1/sec)
99.08 0.939
168.9 6.794
193.7 12.63
203.2 18.26
203.7 21.99
210.3 27.85
211.2 33.46
212.9 39.09
214.8 43.07
213.8 48.68
213.7 54.53
218.5 60.14
218.4 64.12
216.9 69.75
213.1 75.59
209.7 79.34
211 84.95
212.9 90.81
204.5 96.42
201.8 99.95

Table A.7 Data sets for K and n values for HPMC at different

 

 

 

 

 

concentrations:
1.0% HPMC 1.5% HPMC
Stress(Pa) Shear rate (1/sec) Stress (Pa) Shear Rate (1/sec)
0.329 0.939 1.051 0.939
1.643 6.794 5.453 6.549
2.759 12.40 9.724 12.40
4.008 18.26 12.35 18.01
4.468 21.99 15.57 21.99
5.782 27.62 17.61 27.62
6.636 33.46 21.29 33.23
7.490 39.09 24.18 39.09
8.212 43.07 25.29 42.82
9.132 48.68 27.99 48.45
9.921 54.53 30.48 54.29
11.10 60.14 31.86 59.92
11.83 63.90 33.05 63.90
12.35 69.51 35.61 69.51
13.07 75.36 37.71 75.14
13.80 79.12 39.42 80.97
14.65 84.95 40.47 84.73
15.57 90.58 41.92 90.58
16.03 96.19 43.62 96.19
16.69 99.95 44.94 99.95
2.0% HPMC 2.25% HPMC
Stress (Pa) Shear rate (l/sec) Stress (Pa) Shear rate (l/sec)
4.402 0.939 6.964 0.939
25.49 6.549 20.43 6.549
42.57 12.40 31.21 12.40
55.98 18.01 39.68 18.01
62.87 21.99 45.14 21.99
74.77 27.62 53.35 27.62
83.18 33.23 59.26 33.23
90.40 39.09 66.23 39.09
95.33 42.82 71.35 42.82
102.3 48.45 77.07 48.45
109.5 54.29 82.65 54.29
~ 116.8 59.92 88.17 59.92

 

115

 

 

 

 

 

116

121.0 63.90 92.11 63.90
126.3 69.51 96.58 69.51
130.5 75.14 101.5 75.36
136.1 80.97 105.9 80.97
140.4 84.73 108.1 84.73
145.0 90.58 112.0 90.58
149.1 96.19 116.5 96.19
151.9 99.95 118.5 99.95
2.5% HPMC

Stress (Pa) Shear rate (l/sec)

9.461 0.939

39.29 6.794

63.01 12.40

79.89 18.26

90.47 21.99

104.8 27.85

117.5 33.46

127.1 39.09

132.0 43.07

141.8 48.68

151.0 54.29

158.1 60.14

163.1 63.90

170.7 69.75

177.5 75.36

182.3 79.12

187.8 84.95

193.7 90.81

198.8 96.42

202.6 99.95

Table A.8 Data for determination of k ’at different angular velocities for
guar gum at different concentrations:

 

 

 

 

 

 

117

1.0% CC 1.5% CC 2.0% GG
N (rev/sec) k' N (rev/sec) k' N (rev/sec) k'
0.006 40.85 0.006 48.74 0.006 34.14
0.048 14.99 0.046 12.17 0.048 13.86
0.088 9.540 0.088 9.309 0.088 10.84
0.128 8.694 0.128 8.608 0.128 10.55
0.156 7.939 0.156 8.415 0.156 10.17
0.196 7.577 0.196 8.222 0.196 10.01
0.236 7.532 0.236 8.143 0.236 9.932
0.278 7.119 0.278 8.073 0.278 9.854
0.305 6.933 0.305 7.978 0.305 9.786
0.346 6.676 0.345 7.990 0.346 9.793
0.386 6.643 0.386 7.986 0.386 9.782
0.428 6.602 0.426 8.019 0.428 9.798
0.455 6.628 0.455 8.028 0.455 9.773
0.496 6.554 0.495 8.029 0.495 9.827
0.536 6.560 0.535 8.016 0.536 9.838
0.565 6.569 0.576 8.000 0.576 9.812
0.605 6.654 0.603 8.001 0.603 9.813
0.646 6.635 0.645 8.001 0.643 9.826
0.686 6.694 0.685 8.017 0.685 9.855
0.711 6.750 0.711 8.034 0.711 9.878
2.25% 66 2.5% 66
N (rev/sec) k' N (rev/sec) k'
0.006 72.47 0.006 69.09
0.048 11.47 0.048 12.62
0.089 8.889 0.088 10.02
0.130 8.566 0.130 9.552
0.156 8.579 0.156 9.432
0.198 8.538 0.198 9.156
0.238 8.394 0.238 9.048
0.278 8.448 0.278 8.945
0.306 8.405 0.306 8.888
0.346 8.590 0.346 8.850
0.388 8.523 0.386 8.798
0.415 8.513 0.428 8.769
0.456 8.540 0.455 8.814
0.496 8.555 0.496 8.798
0.538 8.519 0.536 8.808
0.565 8.445 0.563 8.789
0.605 8.473 0.605 8.792
0.645 8.448 0.645 8.834
0.686 8.327 0.686 8.799

Table A.9 Data for determination of k ’at different angular velocities for
HPMC at different concentrations:

 

 

 

 

 

1.0% HPMC 1.5% HPMC
N (rev/sec) k' N (rev/sec) k'
0.006 0.001 0.006 4.867
0.048 0.201 0.046 1.470
0.090 0.453 0.088 1.460
0.130 0.533 0.128 1.205
0.156 0.347 0.155 1.807
0.198 0.391 0.196 1.436
0.238 0.396 0.236 1.159
0.278 0.391 0.278 1.198
0.306 0.675 0.305 1.001
0.346 0.617 0.346 0.876
0.388 0.581 0.386 0.876
0.428 0.536 0.426 0.767
0.456 0.769 0.453 0.863
0.496 0.693 0.495 0.861
0.538 0.642 0.535 0.760
0.565 0.515 0.576 0.757
0.605 0.758 0.603 0.748
0.645 1.087 0.643 0.734
0.686 1.546 0.685 0.791
0.711 1.197 0.711 0.716
2.25% HPMC 2.5% HPMC
N (rev/sec) k' N (rev/sec) D*F = k'
0.006 56.32 0.006 24.11
0.048 27.49 0.048 9.975
0.089 16.64 0.088 6.378
0.118 13.53 0.130 5.313
0.159 12.52 0.156 4.860
0.201 10.94 0.198 4.309
0.243 9.681 0.238 4.126
0.270 9.645 0.278 3.922
0.311 8.879 0.306 3.822
0.353 8.439 0.346 3.756
0.381 7.968 0.388 3.657
0.423 7.957 0.428 3.601
0.465 7.557 0.455 3.645
0.491 7.436 0.496 3.552
0.533 7.216 0.536 3.636
0.575 7.132 0.563 3.615
0.603 6.909 0.605 3.595
0.645 6.814 0.645 3.609
0.686 6.601 0.686 3.658

 

118

Table A.10 Rheograms obtained for different food products comparing
the results obtained from MVl and Helical Ribbon systems:

 

 

 

 

 

Mustard (MVl) Mustard (HR)

Shear Rate Apparent Shear Rate Apparent Viscosity
(1/sec) Viscosity(Pas) (l/sec) (Pas)
2.890 11.63 2.849 15.28
5.540 8.057 5.426 8.925
8.350 7.330 8.054 6.387
11.00 5.420 10.72 5.097
13.49 4.610 13.17 4.307
16.15 3.973 15.94 3.761
18.73 3.573 18.51 3.348
21.45 3.167 21.26 3.027
24.04 2.893 23.91 2.768
26.61 2.650 26.50 2.580
29.26 2.500 29.14 2.405
31.91 2.317 31.82 2.255
34.40 2.183 34.51 2.121
36.98 2.077 37.02 2.017
39.71 1.967 39.76 1.911
42.28 1.863 42.25 1.824
44.94 1.780 44.93 1.744
47.59 1.703 47.57 1.673
49.86 1.555 49.91 1.614

Ketchup MVl Ketchup (HR)
Shear Rate Apparent Shear Rate Apparent
(l/sec) Viscosity(Pas) (l/sec) Viscosity(Pas)
5.692 6.410 5.397 6.986
8.276 4.676 8.163 5.009
10.84 3.800 10.81 4.005
13.41 3.153 13.45 3.364
16.07 2.700 16.13 2.961
18.73 2.373 18.79 2.656
21.29 2.140 21.44 2.411
23.79 2.010 24.06 2.205
26.60 1.827 26.62 2.051
29.03 1.697 29.47 1.902
31.83 1.577 31.99 1.779
34.40 1.467 34.73 1.672
37.06 1.400 37.50 1.577

 

119

 

 

 

 

39.47 1.340 40.12 1.504
42.20 1.280 42.88 1.430
44.78 1.243 45.32 1.375
47.43 1.207 48.14 1.316
49.78 1.183 50.47 1.271
Henri's Ranch (MV 1)
Shear Rate Apparent Shear Apparent
(1/sec) Viscosity(Pas) Rate (l/sec) Viscosity(Pas)
8.120 6.183 8.183 3.834
10.77 4.577 10.86 3.286
13.41 3.877 13.42 2.915
15.92 3.423 16.14 2.663
18.56 2.980 18.69 2.469
21.05 2.763 21.28 2.318
23.87 2.533 24.08 2.174
26.52 2.417 26.45 2.069
29.10 2.140 29.20 1.975
31.67 2.067 31.91 1.887
34.33 1.903 34.38 1.813
36.98 1.867 37.12 1.748
39.55 1.867 39.80 1.677
42.20 1.760 42.32 1.627
44.71 1.687 44.85 1.586
47.42 1.657 47.51 1.546
49.78 1.573 49.87 1.510

 

120

Table A.11 Data for Kraft Fat Free Mayonnaise at different
temperatures with automatic addition of 8.5 ml water at 4.0

 

 

ml/min:
Temp 5C Temp 21 Temp 37 C
Strain Apparent Strain Apparent Strain Apparent
History Viscosity History Viscosity History Viscosity
8.750 84.76 8.880 65.49 9.001 53.76
17.03 81.42 17.10 61.21 17.48 50.49
25.39 75.59 25.44 58.29 25.98 46.88
33.69 68.36 33.86 51.86 34.50 43.60
42.13 65.10 42.16 49.90 42.97 41.10
50.47 61.93 50.60 45.86 51.47 39.25
58.71 59.88 58.84 43.46 60.04 37.25
67.05 58.24 67.20 41.54 68.63 35.75
75.43 55.42 75.56 38.06 77.03 34.33
83.78 49.82 83.91 34.26 85.55 31.73
92.11 46.06 92.28 32.95 94.06 29.52
100.4 43.20 100.6 32.70 102.5 27.35
108.8 44.32 108.9 31.38 111.2 27.10
117.5 43.58 117.3 30.19 119.5 25.75
125.4 43.80 125.7 29.15 128.1 24.99
133.7 43.02 134.7 27.01 136.6 22.88
142.2 41.26 142.1 25.73 145.1 21.76
150.4 39.56 150.7 24.89 153.6 19.68
158.7 37.63 159.1 24.60 162.2 18.28

 

121

Table A.12 Data for Kraft Light Mayonnaise at two temperatures with
automatic addition of 8.5 ml water at 4.0 ml/min:

 

 

Temp 5C Temp 21
Strain Apparent Strain Apparent
History Viscosity History Viscosity
8.870 128.6 14.02 80.25
17.36 124.8 27.31 71.81
25.62 121.3 40.61 63.06
33.93 117.2 53.88 53.41
42.29 109.6 67.18 47.79
50.58 103.0 80.40 39.76
58.92 97.23 93.67 30.38
67.25 92.61 107.0 23.63
75.54 92.83 120.2 21.82
83.88 91.90 133.5 21.04
92.25 91.43 146.8 20.93
100.5 87.77 160.1 20.03
108.8 84.44 173.4 17.55
117.1 78.78 186.7 13.18
125.5 73.93 200.0 11.36
133.8 70.67 213.2 11.63
142.2 69.11 226.4 10.61
150.5 66.02 239.8 11.36
158.7 65.14 253.0 10.36

 

122

Table A.13 Data for Kraft Real Mayonnaise at 5C temperature with
automatic addition of 8.5 ml water at 4.0 ml/min:

 

 

Temp 5C
Strain History Apparent Viscosity
8.756 130.2
17.09 126.0
25.42 115.7
33.67 101.0
41.95 87.11
50.32 67.52
58.74 58.19
66.97 61.14
75.33 63.79
83.61 61.20
91.88 53.41
100.2 43.70
108.5 40.83
116.8 37.67
125.2 33.07
133.4 29.85
141.8 29.37
150.2 30.87
158.5 31.96

 

123

Table A.14 Data for Kraft Miracle Whip at different temperatures with
automatic addition of 8.5 ml water at 4.0 ml/min:

 

 

Temp 5C Temp 21 37 C
Strain Apparent Strain Apparent Strain Apparent
History Viscosity History Viscosity History Viscosity
19.80 127.5 17.50 46.22 8.720 87.05
28.14 124.3 34.40 43.76 17.01 82.50
36.46 119.9 51.10 40.93 25.25 76.97
44.82 112.1 67.70 32.69 33.46 70.56
53.13 98.41 84.40 26.74 41.71 62.50
61.36 82.03 101.2 21.26 49.95 51.73
69.72 67.83 117.8 17.10 58.18 39.98
78.03 59.91 134.5 12.42 66.48 30.50
86.32 53.10 151.3 9.780 74.65 25.01
94.68 48.34 168.0 9.990 82.90 21.42
103.0 45.13 184.8 8.850 91.21 20.25
111.2 41.44 201.4 6.760 99.40 18.93
119.5 40.35 218.4 6.600 107.6 17.59
127.9 39.50 234.8 6.680 115.8 16.31
136.2 39.70 251.6 6.130 124.1 14.44
144.6 38.16 268.4 5.400 132.3 12.37
152.8 36.85 285.0 4.420 140.6 12.31
161.1 37.07 301.7 3.890 148.8 10.92
170.3 35.55 318.5 4.050 157.1 9.850

 

124

Table A.15 Data for Hellmann’s Real Mayonnaise at two temperatures
with automatic addition of 8.5 ml water at 4.0 ml/min:

 

 

Temp 5C Temp 21
Strain History Apparent Viscosity Strain History Apparent Viscosity
11.62 111.1 8.730 58.17
19.92 106.0 18.07 54.96
28.25 98.15 25.47 56.51
36.63 90.37 33.84 50.35
44.99 74.77 41.25 43.53
53.27 59.08 50.41 40.68
61.65 45.32 58.86 26.88
70.04 36.64 66.91 28.30
78.36 30.40 74.69 22.08
86.74 25.68 82.48 19.77
95.11 22.64 91.36 14.55
103.4 18.42 99.85 17.19
111.7 16.05 107.7 13.31
120.1 13.95 117.2 15.91
128.4 12.72 124.1 13.31
136.8 10.79 133.1 18.73
145.7 6.320 148.9 13.99
156.6 3.490 156.0 15.23

 

125

Table A.16 Data for all the food products at 5°C at 1.25 l/sec shear rate
with automatic addition of 8.5 ml water at the rate of 4.0

 

 

ml/min:

Kraft Fat Free Kraft Light Mayo Kraft Real mayo
Strain Apparent Strain Apparent Strain Apparent
History Viscosity History Viscosity History Viscosity

8.750 84.76 8.870 128.6 8.750 130.5
17.03 81.42 17.36 124.8 17.09 126.0
25.39 75.59 25.62 121.6 25.42 115.7
33.69 68.36 33.93 117.2 33.67 101.0
42.13 65.10 42.29 109.6 41.95 87.11
50.47 61.93 50.58 103.0 50.32 67.52
58.71 59.88 58.92 97.23 58.74 58.19
67.05 58.24 67.25 92.61 66.97 61.14
75.43 55.42 75.54 92.83 75.33 63.79
83.78 49.82 83.88 91.90 83.61 61.20
92.11 46.06 92.25 91.43 91.88 53.41
100.4 43.20 100.5 87.77 100.2 43.70
108.7 44.32 108.8 84.44 108.5 40.83
117.1 43.58 117.1 78.78 116.8 37.67
125.4 43.80 125.5 73.93 125.2 33.07
133.7 43.02 133.8 70.67 133.4 29.85
142.1 41.26 142.2 69.11 141.8 29.37
150.7 39.56 150.5 66.02 150.9 30.87
158.7 37.63 158.7 65.14 158.4 31.96

 

126

Cont.

 

 

Kraft Miracle Whip Hellmanns Real Mayo
Strain Apparent Strain Apparent
History Viscosity History Viscosity
19.80 127.5 11.62 111.1
28.14 124.3 19.92 106.0
36.46 119.1 28.25 98.15
44.82 112.1 36.63 90.37
53.13 98.41 44.99 74.77
61.36 82.03 53.27 59.08
69.72 67.83 61.65 45.32
78.03 59.91 70.04 36.64
86.32 53.10 78.36 30.40
94.68 48.34 86.74 25.68
103.0 45.13 95.11 22.64
111.2 41.44 103.4 18.42
119.5 40.35 111.7 16.05
127.9 39.50 120.1 13.95
136.2 39.70 128.4 12.72
144.6 38.16 136.8 10.79
152.8 36.85 145.1 6.320
161.1 37.07 156.6 3.490
170.3 35.55

 

127

Table A.17 Data for all the food products at 21°C at 1.25 l/sec shear
rate with automatic addition of 8.5 ml water at the rate of
4.0 ml/min:

 

 

Kraft Fat Free Kraft Light Kraft Miracle Hellmanns Real
Mayonnaise Mayonnaise Whip Mayonnaise
Strain Apparent Strain Apparent Strain Apparent Strain Apparent

History Viscosity History Viscosity History Viscosity History Viscosity
8.880 65.49 14.02 80.25 17.50 46.22 8.734 58.17
17.10 61.21 27.31 71.81 34.42 43.75 18.06 54.96
25.44 58.29 40.61 63.06 51.05 40.95 25.46 56.51
33.86 51.86 53.88 53.41 67.70 32.68 33.83 50.35
42.16 49.90 67.18 47.79 84.39 26.73 41.25 43.53
50.60 45.86 80.40 39.76 101.1 21.25 50.40 40.68
58.84 43.46 93.67 30.38 117.7 17.09 58.86 26.88
67.20 41.54 107.0 23.63 134.5 12.41 66.91 28.30
75.56 38.06 120.2 21.82 151.3 9.782 74.69 22.08
83.91 34.26 133.5 21.04 168.0 9.991 82.48 19.77
92.28 32.95 146.8 20.93 184.8 8.853 91.34 14.55
100.6 32.70 160.1 20.03 201.4 6.762 99.85 17.19
108.6 31.38 173.4 17.55 218.3 6.602 107.7 13.31
117.3 30.19 186.7 13.18 234.8 6.677 117.2 15.91
125.7 29.15 200.0 11.36 251.5 6.135 124.1 13.31
134.0 27.01 213.2 11.63 268.4 5.399 133.1 18.73
142.4 25.73 226.4 10.61 284.9 4.425 140.1 11.19
150.7 24.89 239.8 11.36 301.7 3.887 148.9 13.99
159.0 24.60 253.1 10.36 318.5 4.055 156.0 15.23

 

128

Table A.18 Data for all the food products at 37°C at 1.25 l/sec shear
rate with automatic addition of 8.5 ml water at the rate of
4.0 ml/min:

 

 

Kraft Fat Free Kraft Miracle whip
Strain History Apparent Viscosity Strain History Apparent viscosity
9.000 53.76 8.720 87.05
17.48 50.49 17.01 82.50
25.98 46.88 25.25 76.97
34.50 43.60 33.46 70.56
42.97 41.10 41.71 62.50
51.47 39.25 49.95 51.73
60.04 37.25 58.18 39.98
68.63 35.75 66.48 30.50
77.03 34.33 74.65 25.01
85.55 31.73 82.90 21.42
94.06 29.52 91.21 20.25
102.5 27.35 99.40 18.93
111.2 27.10 107.6 17.59
119.5 25.75 115.8 16.31
128.1 24.99 124.1 14.44
136.6 22.88 132.3 12.37
145.1 21.76 140.6 12.31
153.6 19.68 148.8 10.92
162.2 18.28 157.1 9.850

 

129

 

 

Table A.19 Data for Kraft Fat Free Mayonnaise at three temperatures
at 1 1/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21C Temp 37C
0.00 19.32 119.8 75.05
0.25 104.6 77.34 58.68
0.50 78.08 49.70 58.60
1.00 40.46 33.60 48.13

 

Table A.20 Data for Kraft Light Mayonnaise at three temperatures at 1
l/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21C Temp 37 C
0.00 19.31 119.8 82.94
0.25 104.6 77.34 53.96
0.50 78.08 49.70 39.89
1.00 40.46 33.60 25.10

 

Table A2] Data for Kraft Real Mayonnaise at three temperatures at 1
1/sec shear rate with manual mixing:

 

 

Vw/Vm Temp 5 C Temp 21 C Temp 37 C
T" 0.00 164.0 117.4 95.65
0.25 93.66 70.47 63.24
0.50 59.04 47.90 38.00
1.00 27.41 23.55 16.64

 

130

Table A.22 Data for Kraft Miracle Whip at three temperatures at 1
1/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 c Temp 21 C Temp 37 C
0.00 146.7 85.53 90.83
0.25 58.11 44.88 47.11
0.50 42.72 33.94 36.30
1.00 24.21 16.66 18.90

 

Table A.23 Data for Hellmann’s Real Mayonnaise at three temperatures
at 1 1/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21 C Temp 37 C
0.00 179.8 109.4 116.9
0.25 80.46 46.30 49.87
0.50 61.94 36.50 30.63

1.00 31.05 15.74 19.62

131

Table A.24 Data for Kraft Fat Free Mayonnaise at three temperatures
at 25 l/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21 C Temp 37 C
0.00 1.230 10.99 4.657
0.25 11.88 8.990 4.260
0.50 9.782 7.045 4.110
1.00 6.697 4.970 3.442

 

Table A.25 Data for Kraft Light Mayonnaise at three temperatures at
25 1/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21 C Temp 37 C
0.00 1.230 10.99 7.392
0.25 11.88 8.990 6.722
0.50 9.782 7.045 5.190
1.00 6.697 4.970 3.537

 

Table A.26 Data for Kraft Real Mayonnaise at three temperatures at 25
l/sec shear rate with manual mixing:

 

 

Vw/Vm Temp 5 C Temp 21 C Temp 37 C
0.00 10.36 7.397 5.895
0.25 7.747 6.055 4.937
0.50 5.710 4.457 3.345
1.00 3.220 2.622 1.795

 

Table A.27 Data for Kraft Miracle Whip at three temperatures at 25
l/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21 C Temp 37 C
0.00 9.570 7.187 6.537
0.25 7.347 5.822 5.077
0.50 5.622 4.592 3.960
1.00 3.775 2.732 2.437

 

Table A.28 Data for Hellmann’s Real Mayonnaise at three temperatures
at 25 l/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21 C Temp 37 C
0.00 8.245 5.335 4.975
0.25 6.200 4.177 3.747
0.50 5.022 3.317 2.580
1.00 3.037 1.905 1.660

 

133

Table A.29 Data for Kraft Fat Free Mayonnaise at three temperatures

at 50 l/sec shear rate with manual mixing:

 

 

Vw/Vm Temp 5 C Temp 21 C Temp 37 C
0.00 3.061 3.150 2.560
0.25 3.300 3.333 2.422
0.50 2.843 2.443 2.320
1.00 2.542 1.996 1.952

 

Table A.30 Data for Kraft Light Mayonnaise at three temperatures at
50 1/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21 C Temp 37 C
0.00 0.690 6.570 4.407
0.25 7.460 5.662 4.275
0.50 6.292 4.627 3.337
1.00 4.542 3.302 2.317

 

Table A.31 Data for Kraft Real Mayonnaise at three temperatures at 50

1/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21 C Temp 37 C
0.00 5.752 4.077 3.250
0.25 4.530 3.597 2.855
0.50 3.450 2.675 1.980
1.00 2.032 1.637 1.112

 

134

Table A.32 Data for Kraft Miracle Whip at three temperatures at 50
1/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21 C Temp 37 C
0.00 5.357 4.247 3.715
0.25 4.712 3.752 3.145
0.50 3.387 2.986 2.455
1.00 2.545 1.850 1.567

 

Table A.33 Data for Hellmann’s Real Mayonnaise at three temperatures
at 50 l/sec shear rate with manual mixing:

 

 

Vw/V m Temp 5 C Temp 21 C Temp 37 C
0.00 4.247 2.792 2.535
0.25 3.567 2.490 2.147
0.50 2.925 1.980 1.510
1.00 1.840 1.210 0.980

 

135

Table A.34 Data for all products at 5°C at 25 1/sec shear rate with
manual mixing:

 

 

 

 

 

Vw/Vm KFF KLM KRM KMW HRM
0.00 5.579 1.230 10.36 9.570 8.245
0.25 5.840 11.88 7.747 7.347 6.200
0.50 4.955 9.782 5.710 5.622 5.022
1.00 4.390 6.697 3.220 3.775 3.037

Table A.35 Data for all products at 21°C at 25 1/sec shear rate with

manual mixing:

Vw/Vm KFF KLM KRM KMW HRM

"“000 5.670 10.99 7.397 7.187 5.335
0.25 6.113 8.990 6.055 5.822 4.177
0.50 4.300 7.045 4.457 4.592 3.317
1.00 3.433 4.970 2.622 2.732 1.905

 

Table A.36 Data for all products
manual mixing:

at 37°C at 25 l/sec shear rate with

 

 

Vw/Vm KFF KLM KRM KMW HRM
0.00 4.657 7.392 5.895 6.537 4.975
0.25 4.260 6.722 4.937 5.077 3.747
0.50 4.110 5.190 3.345 3.960 2.580
1.00 3.442 3.537 1.795 2.437 1.660

 

136

Table A.37 Data for all Kraft Miracle Whip samples at 21°C at 25 1/sec
shear rate with manual mixing:

 

 

Vw/Vm 219 221 234 240-1 240-2
0.00 6.41 6.15 6.72 6.74 7.00
0.25 5.78 5.71 6.07 5.89 6.09
0.50 4.67 4.36 5.09 5.25 5.36
1.00 4.08 3.17 4.04 3.36 3.74

 

137

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