THE EFFECT OF BATCH SIZE. UPON THE
FLOW OF CHOCOLATE PIE. FlLLENG

W033; For fho Degree of M. 5;
MICHQGAN' $TATE COLLEGE
.Qrace A. Miller}
1955

«HF-5‘5

This is to certify that the

thesis entitled

The Effect of Butch Sire U703 the
Flow of Chocolate Pic Fillln:

presented by

Grace A. Ifill er

has been accepted towards fulfillment
of the requirements for

gazcfior of Science degree in Ififi‘Tffi‘lti‘l“ Ag‘nirirttration

(«if 141:»:

Major professor

Date J‘L-_‘._._"'j_“.t I}; lqrr

0-169

’r

 

THE EFFECT OF BATCH SIZE UPON THE FLOW

OF CHOCOLATE PIE FILLING

By

Grace A. Miller

”In.

AN ABSTRACT

Submitted to the School of Graduate Studies of Michigan
State College of Agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of

FASTER OF SCIENCE

Department of Institution Administration

Year 1953

THESE?

H‘r‘ '7‘." . m
A50 gin? L

This study was directed {rinarily toward the onective censure-

ment of flow of COOLCd, cut earpies of starch—thickened chocolate pie

f ‘V

0'1. ‘. _/ _'
fliiln: prepared in o, c, JV, 1

, and .4-gal;on baton sizes.

‘

3 i
The selected formula used throughout this study was one in which
the proportion of ingredient‘ was held constant and the thicacning agents
were limited to cornstarchrand cocoa powder. These thick ning agents
were conbinei in eguai weights and together constituted 7.: per cent of

the total weirn

i.)

(+

of the mixture.

The treatment variable, introiuced at the end of tne heating
process, consisted of holding the sass in the stean Jackctei kettle
after the mass had reached a teaperature of €300. Holding periods were
arbitrarily set at Q, 5;, and 6e rinutes.

' 5

Several pieces 0 equipment were deeignel for Treyarinr sarplcs

and determining the arount of spread from out sauples of ccoied fil;ing.

The testing eguipaent used in this research and the consecutive steps

in the proceiure for pouring the roll, cutting and leveling the sarple,

releasing the saxple for flow, recording the image of the sacp-e, and

measuring the sarple area are photographicaliy illustrated in the thesis.
From the data of this investigation it apneared that flow charac—

L

teristics of cooled, cut caiwles o? starch—thickened pastes are not

\
I

consistently affected by increases in batch sise anen procedure and
proportion of ingreiients rcnain constant. Batches of i, E, is, and
‘I

lZ-galion aaounts produced gs otructures of similar consistency. Al-

though the lh—gallon amount produced a less stable gel structure than

‘

did any of the other catch sizes tested, factors other than batch size
nay'also have influenced the flow of staples.

In this linited study it was found that a progressively longer
cooking period is required to reach the points of visible, initial
viscosity and end cooking tenperature for each consecutive increase in
batch size. It appeared that he degree of swell of the starch granules
is dependent upon batch size, rate of heatini, and tenperature of the
bass during the heating and holding periods.

The length f the no-ding tire, after the temperature of £200
is attained, appeared to affect the stability of the gel structure in
all batch sizes. Rigidity of gel structure increased sore during the
first 5o rinutes of ho;ding tine than during the following 3o minutes
of holding time. This fact suggests that the rate of heating and the
length of the holding period are contributinr factors in the final flow
of the cooled paste.

The gels resulting fro: the ju-ninute holding period were judged
suitable for use as gudding for all batcn sizes tested; saaples from
the 6Q-ninute holding period gave gels acceptable for use as Hie filling.
In all cases gel structure of saryles held as minutes was tender and
stable. These facts suggest the possibility of regulating stability and
tenderness of cooled starch-thickened mixtures, for specific batch sizes,
by the contrOl of tide and teeperature conditions of the cooking period.

The findings of this linited study ernhasize that accurate pre-
diction of the stability of rel structure of starcn- nichencd routes is

a couelex problem. Additional investigation of the interaction of factors,

such as rate of heating, terrerature of the sass during the heating period,

end cooking teuperature, and length of ho;ii¢g period after the appli-
cation of stone is discontinued, needs to be made before the effect of

baton size upon flow can be accurately detereined.

THE EFFECT CF BRTCH SIJE UICJ The FLOW

CF CLOCCLATE FIE FILLING

By

Grace A. killer

A TEES IS

Subnitted to the School of Graduate Studies of Lichigan
State College of Agriculture and Applied Science
in partial fulfillLent of the requirements
for the degree of

“rm
v21-

LASTER CF SCIEH

Department of Institution Administration

Year 1955 {l

AShNCWLEDGLEHTS

The writer wishes to express her gratitude and apgreciation to
Dr. Pearl J. Aldrich for her encouragenent and guidance during the
preparation of this thesis, and to Dr. William D. Eaten for assistance
in the statistical analysis of the data. Grateful acknowledgement is
also due to Professor Katherine h. Hart for her interest in the project
and her assistance in reading the manuscript.

She also wishes to thank Dr. hargaret A. Chlson for the use of
the Compensating Polar Planineter used in this study.

The cooperation of hildred L. Jones, Food Director, in permitting
the production and utilization of the experimental product in the

Caapus Food Service Units was appreciated.

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Inherent Starch Characteristics . . . .
Treatment of Starch durinn ranufacture.
Effect of Electrolytes. . . . . . . . .
Concentration of Starch . . . . . . . .
Effect of Time and Teaperature. . . . .
Efpect of Fatty Acids . . . . . . . . .

EEF€CL Of SUCI‘OSC e o e o e o e e o e e

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'ffect of Batch Siae on Flow frcierties

Objective Tests for Starch Lasts. . . .

Jisccsity Leasureaerts . . . . .

Scott test for hot paste

I “"

e:,ler viscozivet~r . .

C)

Brookfield viscosineter .
Sratender luylorraph. . .
Caesar consistoneter. . .
Corn Industries viscoaete
Line-spread test . . . . . . . .

Grawemeyer and Pfund test

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Gel strength tests .

Exchange Ridgelimeter

Tarr—Eaker jelly tester

ZTS (contd.)

I I I I I I I I I I
I I I I I I I I I I
I I I I I O I I O 0

Kerr uoiification of Saare and bartens test

Fuchs penetroneter.

PROCEDURE. . . . . . . . . . . . .

DeveloI
Basic Fornula . . . . . . .
Treatment . . . . . . . . .
Batch Size. . . . . . . . .
Freparation of “anples. . .
Objective hcasuresent . . .
Illustration of Technique .

DISCUSSION AID RESULTS . . . . . .
Cold Paste Viscosity Tests.

lroduction technique
Tine and temperature
Treatment. . . . . .

SLlfihRY. . . . . . . . . . . . . .

CC‘NCLUSICl‘B. . . . . . . . . . . .

iITERATCRE CITbD . . . . . . . . .

APPENDIX . . . . . . . . . . . . .

iv

snent of Testing Equipment.

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LIST OF IaBLES

Summary of treataent averages of batch sizes tested.
(square centimeters). . . . . . . . . . . . . . . . . . .

.‘tnalySis Of variayjce for flow I I I I I I I I I I I I I I

Sunlary of analyses of variance within 4 replications,
for i treatments for each of } batch sizes. . . . . . . .

Susuary of average flow readings of four replications
of each batch size for each treatnent . . . . . . . . . .

Analyses of variance for treatuent with 4 replica ions
and 5 batch sizes . . . . . . . . . . . . . . . . . . . .

Keasurement of flow: original data. llaniteter readings
in square centireters . . . . . . . . . . . . . . . . . .

Summary of range and mean flow measureaents for each
batch size. (square centimeters) . . . . . . . . . . . .

Per cent flow deviation From mean of samples within
eaCh batcl’x Bil; I O O O O O C C O O I O I O O O O O O O 0

Chocolate pie filling formula . . . . . . . . . . . . . .

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LIST OF FIGURES

Molding equipment:
couplets assembly . . . . . . . . . . .

Pouring the sold. . . . . . . . . . . .

Inserting the sample cutter. Individual

complete assembly of san;-e cutter. . .
Removing of the upper glass plate . . .
Removing the metal mold . . . . . . . .

Removing the excess filling

'the sample cutter . . . . . . . . . . .
Leveling the sample . . . . . . . . . .

Releasing the cut sample for flow . . .

Recording the sample area on Technifax blue—line

F‘aper C I O O O O O O O O I I O O O O 0

fr a the outer

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partial

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and
and
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heasuring the sanple area with the compensating

planineter. . . . . . . . . . . . . . .

Average time—temperature relationships of batch

during the cooking process. . . . . . .

”ffect of holding time on the average flow of batch

sizes of chocolate pie filling. . . . .

vi

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STRCDUCTICN

The lack of ability to predict accurately the amount of flow
for cooled, starch—thickened pie filling is a very real problem to
quantity food production workers. Daily adjustments in food produc-
tion scledules often require batch-size changes in established fornu—
las. The usual practice of increasing batch size by the direct multipli-
cation of each ingredient in a basic recipe, with all procedure factors
remaining constant, frequently has failed to produce a filling comparable
to the one obtained from the original formula. Large batch foraulas
derived by this technique generally tend to produce a consistency too
soft for serving. The pie—baker's solution for this dileuna is often
siuply to increase the proportion of thickening agent in an attenpt to
attain conparable consistency.

A survey of chocolate pie filling recipes in large quantity cook
books revealed that wheat flour and cornstarch are the thickening agents
Lost frequently used. Whole egg or egg yolk and chocolate or cocoa also
contribute some thickening effect.

In an attempt to control as nany ingredient variables as possible,
cornstarch and cocoa powder were used in the formula for this study to
obtain the desired consistency. Formulas including whole egg or egg
yolk were not considered. Whole dried silk solids and tap water were sub-
stituted for whole fluid milk to obtain milk of constant composition.

The first objective of this investigation was to deterrine the
effect of batch size on flow of the cooled filling by objective ceasure-
sent. Throughout this study the forsula contained constant proportions

of all ingredients.

[U

The literature contains reports of a few experinental studies in
which the flow of hot, starch-thickened pastes has been neaeured objec—
tively by line—spread tests. The investigator has not found any reports
of the use of objective measurement of flow for cut sahples of cooled
filling. Bone flow predictions for out sauples of cooled filling have
been based Upon measurable flow data obtained from hot paste satples.

The second objective of this_study, therefore, is to develop a technique
to deterbine the anount of spread from a cut sanple of cooled filling
under specific conditions.

Contemporary starch chenists have now generally agreed that via-
cosity and gel strength are two separate and distinct properties of
starch pastes and are not synonyuous as believed earlier. Research work-
ers have substantiated the theory that tins and temperature relationships
of starch-thickened pastes have a direct bearing on the physical character-
istics of the finished product. Acceptance of this point of view suggests
that the neasurenent of flow of hot pastes and of cold pastes are, in
effect, testing totally different properties which are not cotparable.

It is the hope of this investigator that the firdings of this study
will serve as a basis from which a production technique, in terms of
tine—temperature relationships, can be developed for use in producing

starch-thickened chocolate pie filling with predictable stability and flow.

REVIEW CF LITERATLRE

Frankel (18), in a treatise on starch, stated that starch or
starch-flour was known to the ancient Egyptians and Greeks. At that

‘nli-

v
A

time it was derived exclusively frou wheat. The production and a;
cation of potato starch appeared first in Europe at the close of the
sixteenth century.- krcbably the greatest use of starch prior to 1850
was as a hair powder, although it was used to a linited extent in the
textile and paper trades. Starch is not only one of the post exten-
sively difosed but also one of the Lost useful ingredients contained
in plants. Late in the nineteenth century Frankel reported that
products from the vegetable world such as potatoes, wheat, maize, and
rice were found to be useful sources for the manufacture of commercial
starch. Since the late 1950's, the research of carbohydrate cheaists
has advanced rapidly and real progress has been achieved in the study
of the conposition, structure and behavior of starch. larsllel ad-
vancements in modern colloidal chemistry have been valuable factors

contributing toward this development.
Chemical Fractions

French (19), in reviewing the chenical properties of starch,
stated that connon starches nay be fractionated into components which
differ both in cheuical properties and in physical behavior. Apparently
starches from different sources, such as corn, peas, wheat, and rice,
differ from each other particularly in conposition.

In 1924 Alsberg and Rask (3) in their work with cereal starches

discovered that certain of these starches produced a blue color with

iodine and others gave a red color. Their findings further indicated
that when a suspension of starch granules in water was heated, those
slurries which gave a red color with iodine converted into Lore viscous
pastes than did those which gave a blue color. Briuhall and Hixon (lo)
stated that starch pastes are a heterogeneous systeu, each constituent
of which may react differently toward changes in the conditions of
measuring viscosity. hany early investigators have advocated this
theory. Only since 1941 has there been general agreeient upon the
nature of starch heterogeneity. The theory is now accepted that the
najority of starches contain molecules which can be classified according
to two quite different structural patterns.

Auylose is designated as the fraction which possesses unbranched
starch chains, dissolves in water without the fornation of a paste, and
gives a blue color with iodine. Schoch (59) indicated that the normal
starches, i.e. corn, wheat, rice, and potato, contain 15 to 50 per cent
abylose. Whistler and Weathcrwax (46) analyzed j? unisproved varieties
of corn and reported an average ahylose content of 2) to 26 per cent.
Heated aLylose solutions froa cannon corn, at concentrations of one
per cent, retrograde or revert to an insoluble state on cooling. Hot
solutions of five per cent concentration of anylose set up rigid,
irreversible gels when cooled to room teLpersture. The tendency of
anylose to retrograde decreases the stability of starch pastes and is
considered a detrimental feature except in products where gel forration
is the primary objective. Studies have shown that waxy strains of maize,
rice, barley and rye contain 0 to 6 per cent atylose. hanson and co-
workers (22, 25) have experimented with the use of waxy rice flour in

the preparation of pro-cooked puddings, sauces, and gravies for freezing.

They concluded that these frozen products, thickened with waxy rice
flour, were sore ctable after thawing than sinilar products thickened
with wheat flour or cornstarch.

Axylopectin represents the constituent of starch which has a
branched chain structure, force a paste with lot water, and gives a red
color with iodine. According to the literature, the relative propor-
tion of auylose to aryloyectin in starch varies greatly. Anylopeotin
c nprises the cajor proportion of the common starches, corn, potato,
wheat, and rice. Aqueous solutions of this fraction are relatively
stable on cooking (59). For this reason anyloyectin is considered the
most important element in starches which are used as thickening agents,
emulsifiers, and sizing agents for paper and textiles. Saaec (fit) con—
cluded that the viscosity of a starch paste depends on the relative
quantity of arylopectin {resent in the starch.

The presence of Shall anounts of non-carbohydrate materials, such
as phosphorous, fatty acids, silicon, and nitrogenous aaterial in the
common starches has long been an established fact. Of these substances
the phosphorous and fatty acids seem to be present in the largest anounts.

The quantity varies with the starch, and those starches which are low in

phoephorous content are correspondingly high in fatty-acid content (A5).
Effect of Swelling on Physical Characteristics

In 192% Alsberg and Rask (2) reported that when an aqueous starch
su3pension was heated, the granules swelled, then burst and finally, lost
their anistropic prOperties. The original suspension was converted into
a more viscous product which was usually teraed a starch faste. These

investigators further concluded that although the exact changes which

took place were not completely understood, they probably involved the
absorption of water by the starch grains with consequent swelling to

a point at which the grains burst. The final result was conversion of
the starch suspension into a sol which formed a rigid gel on cooling.
This conversion they defined as gelatinization. In a later study
Alsberg (l) substantiated the view of earlier workers that LOBt types

of starch heated in a water suspension do not disintegrate to form a
colloidal solution. Starch granules Lerely swell and the process is a
gradual one. Different starches increase their volumes to different
degrees when heated in water, and even individual granules in the same
sanple swell to different degrees. On this basis Alsberg concluded that
viscosity was attributable to unbroken swollen granules which still con-
tained their quota of constituent anyloses.

Brinhall and hixon (ll) employed nicroscopic technique in observ—
ing the progressive swelling of granules in water suspensions. They
concluded that the starch granules ceased swelling and becane wrinkled
when the temperature was increased beyond the point of naxinun rigidity.
Since there was no evidence of rupture in the membrane, they attributed
these changes to the increased perneability of the nenbrane. Because of
this increased perueability the membrane then offered no resistance to
the exchange of contents with the outside medium. Anker and Geddes (5)
contented that granule disintegration was unicyortant to viscosity until
swelling had progressed to the goint where the granules becase closely
packed. The extent of granule rupture appeared to increase with concomi-
tant increases in internal shearing stresses. In 1950 Bechtel (5)

supported the theory that starch undergoes a complex series of changes

during the cooking period. Chronologically these changes include swelling,

collapse of the granule, solution of some of the constituents, and comp
plete granule disintegration. Schoch (59) suggested that the starch
granule is coupletely insoluble in water at room tenperature but swells
progressively upon heating until its outline becomes vague. The swollen
granule is still present and the consistency and paste-like character-
istics of the starch suspension are attributable to the nechanical
jostling of these swollen masses. herr (26) reviewed the results of many
research workers and presented evidence that swollen starch granules
aaintained in water in excess of 600 C slowly contract. Any application
of high shearing stresses to these distended granules could result in
their rUpture.

Throughout earlier literature concerning the physical behavior of
starch, confusion resulted fron the inconsistent use of descriptive
terns. More recent publications show greater compatibility in this
respect. The term gelatinization nay be defined as the process of con-
verting a starch suspension to a sol which gels on cooling. Gelation is
the formation of a gel or solidification of a sol. Gel is the term used

to describe the jelly-like precipitate of a colloidal solution.
Viscosity

According to Hadley (57), starch granules occupy a nuch larger
volune in the systen after swelling and gelatinisation than before. Vis—
cosity depends only on the volume of the dispersed phase and not on
the degree of diapersion. Frequent references can be found in which the

consistency of starch pastes is described as apparent viscosity" (2, 7, 2t).

Bechtel and Fischer (7) stated that apparent viscosity is essentially a

shear-depenlent viscosity and is established by the ratio of shearing

to rate of shear. Kerr (23) reported that starch pastes exhibit an
anoualous viscosity. The effect measured is the result of a coubination
of many inherent properties of starch which has been gelatinized in
aqueous media. Viscosity measurehents are couplicated by plasticity

and elastic effects which arise from residual structure units of starch
granules or new structural units in the paste which form through associa-
tive forces of the molecules. Bjostroa (41) concluded that viscosity of
a paste is not identical to visc0aity or fluidity of a hcsogencus liquid.
Viscosity in the paste is attributable to whole or disintegrated granules
in suspension and is a teasure of the degree to which the swollen granules
crowd toietner. Schoch (4o) concluded that such of the viscosity of a
cooked paste must be attributed to swollen aggregates of granular struc—
ture because such pastes can be readily thinned by autoclaving or violent
mechanical action.

Caesar (13) stated that consistency changes in a pure starch and
water paste are coalrised of four broad phases: starch and water suspen—
sion, gelatinisation of the starch granule, partial rupture of the starch
cells, and association or retnickening. Sons of the variables which may
affect the viscosity of a starch paste involve the inherent starch char-
acteristics, treatnent of starches during manufacture, concentration of
the starch, tresence of electrolytes, nechanical injury of the aolecules,

pH of the cooking nediun, and the time and temperature of cooking.

Inherent Starch 7hsracteristics

The findin;s of Lany research workers hive indicated that the
natural characteristics of starch granules influence the behavior of the
granules luring gelatin'sation. herr (it) asserted that starch granules
from different sources show vast variety in shage and size. It has long
been established that the larger granules of any garticular type of starch
gelatinize tore easily than the staller :ranules. It now appears that
there may be s as correlation between the lispereibility of a type of
starch and its average Franule size. Xhistler and inert (4)} stated that
starches ray be distinruished by exazination of the size and shape of
graiules, the texterature at which they gelatiniae in water, the rate of
swelling in various solves s, and the extent to which they csnbine with
iodine.

In 1952, Caesar (l3) exterirented with 2o ,er cen starch gastes

f high grade, ospzercial branls of tarioca, notato, sass, corn, and
:heat. These pastes were prepared on the basis of moisture content,
submittel to tlorough agitation, and slowly heated to the boiling yoint.
Caesar concluded that the consistency of the pastes tested was in the
ease order as listed, ranging fro; the greatest to the least.

Eahgels and Bails" (jj) exyeriaented with hard s rih {atent, hard

winter patent, soft winter [atent, and iurun wheat. Cold {elatinizing

reagents were used and the swelling carscity was noted by viscosity

A

j

leasureaent. From the results of this investigation they consiuded that

cheuical differences which cause di'ferences in {h cal grogerties of

’5.

'VIQ
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J

starch are con

>~1

lex in nature and any be attributable to structural dif-

ferences in the starch g anule.

Harris and Jesyerson (2)) studied the physiochenical groycrties
of a series of exuerinentally grepared wheat starches. They found that
the swelling tower of wheat starch decreased with maturation irrespective
of variety or environtental conditions. Gel strength and viscosity
tended to increase with ripeness. Further research indicated little
difference in viscosity and swelling power among wheat, rice, and barley
starches. however, they reported data which suggested that potato starch
possessed much higher viscosity and swell than the concon cereal starches.
In the sane year, Harris and Jesgerson (2}) offered further data which
substantiated the hyyothesis\that factors affecting the swelling property
of the starch granule are complex. They found that differences in swell-
ing power were significant aaong codified wheat, barley, and corn starches.

Woodruff and Faclastcrs (47) studied corn and wheat starches and
concluded that the pasting results of some of these starches varied appre-
ciably. In studyinfi various couxercial starches Iutting (55) observed
that gotsto starch swelled cost and produced the cost viscous, unstable,
and variable paste. This verified the earlier findings of Harris and
Joeyerson (25). Results of the experisent of Tanner and Englis {#2)
with different varieties and types of corn indicated that cereal starches
tend to groduce susgensicns of low viscosity at relatively high conCen—
trations, whereas non-cereal starches, such as potato, tapioca, and arrow—
root, form highly viscous sustensions at relatively low concentrations.

From th stuiies of Caribell and co-workers (1}) it aypeared that
specific use characteristics and finished product qualities of starch
were closely related to water absorption, swelling, and granule rupture.
In evaluating starches for specific uses, viscosity and gel formation

were judged to be influential characteristics.

ll

Treatment of Starch during banufacture

Consistency changes in hot tastes from three different comnercial
cornstarcnes were studied by Caesar (13). his findings indicated that
the tnree Starches varied in swelling pomer and stability. Two starches
thickened ouichiy and to a greater degree than the third sample. Boas
investiyators 26, 40, a?) isolated starcnes in the laboratory. All
found these pretared starcnes to differ measurably from the commercial
types.

In his account of the sanufacture of modified corn starches, Kerr
(25) asserted that the degree of alteration of native starches affects

the chenioal properties of he stIrCS granule an; that these changes may

range from the simple to the coctlex. bone industrial ayglications of
starch require freeioa frcc undesirable odors and discoloration. Kerr (26)
resorted that stirch of sugcrior whiteness without objectionable odors

can be produced by the use of an oxidising agent followed by a prolonged
drying action.

Starchss in which the ynysical characteristics have been modified
are condonly classified as mobile, thin-boiling, and heavy-boiling starches.
Evidence of nobility in a starch, according to Kerr (:5), is characterived
by its ability to creite dust when agitated, to alhere and spread sore
evenly than normal stirches, ahi to exhibit greater volume per unit of
wciqht. Reasons for iiffcrences in mobility of starches are not clearly
understood.

Sjostrou (Al) stated that the noaified starch yranul:: in a thin—
boilir; starch taste still swell and disinthrate in hot water but have

a lesser defrce of hydration than ordinary starch granules. bjostrom

' a

’4 J

Staggested that although other factors affected the difference in fluidity

tpedmeen thick—boiling and thin—boiling sestes, this relation in volume
was the most ixrgortant.
In 1941 Schoch (he) reported that it was possible to raise the

'c>lubility of starch by certain oheuical codificati ns. Treatnent of raw

I

(

t,arch with oxidising agents, such as alkaline hytoohlorite or peroxide,
‘ Tiereeeed solubility but decreased viscosity. With thin—boiling starches

*‘r‘cduced by acid treataent the reaction was one of glucosidio hydrolysis

reduced the size of the starch rolecule from its highly associative

’w’ h 1 Ch
cc>lloidal dimensions. Reports by Kerr (3t) indicate that the majority
c>f starches which are zarketed have viscosity below that of rative starcn.
.As a result of this reduction, 3 higher proyortion of dry substance is re—
quired to thicken a given volume of liquid than the proyortion of native
Starch needed to thicken the cane volure of liquid. Furthermore, the
,pasted groduot fron these so-called thin-boiling starches is fluid enough

to be workable. The most COLLCH method used to Lodify starch for this pur-
pose is by treatncnt with dilute acid. A thin-boiling starch granule swells
considerably less than untreated starch, and the reduction in hot paste
viscosity is the direct result of the decreased tendency to swell.

Echoch (ho) presented evidence that prolonged dry-grinding in a
ball unit disintegrated natural, unxodified starch granules. This re—

sulted in a rarked reduction in their pasting ability and further verified

the data of earlier workers (1, 5, 28).

15

Effect of Electrolytes

A major portion of the experirental work reported in the liter-
ature indicated that distilled water was used as the liquid cediun of
control on pasting tests for starch. Bechtel (5) stated that starch
undergoes a conplex series of changes during cooking and that the rate
of change is partly attributahle to the presence of materials other than
starch. Bisno (9) concluded that variations in the cheuical coagosition

‘nificant differences

3

of the water sup*ly were sufficient to result in sig
in the consistency of pie fillings. A change to distilled or softened
water freguently resulted in noticeable changes in stability, viscosity,
and tendency to gel. Kerr (BE) investigated the effect of salts on the
precipitation of starch granules. Kerr reported that the starch from a
suspension which contained no sodium chloride settled more slowly than
did the starch fron a second sanple containing sodium chloride.

Bechtel (6) studied the effect of differences of ;H on the pasting
characteristics of several counercial starches. Adjustments in pH were
achieved through the addition of small amounts of HCL or NaOh to starch
slurries inneiiately preceding the viscosity test. This Lethod was
followed to asproxinate the codnercial method of neutralizing starches
after their codification and to avoid the introduction of ions contained
in buffers. Bechtel suggested that such ions may have inportant effects
on viscosity as sncwn by the variability found in results of tests at the
same pH with different buffers. He concluded that differences in pH gave
different effects on unmodified and acid-uodified cornstarch. The temper—
ature of initial viscosity rise and the teuperature at aaxinum viscosity

were appreciably altered. Bechtel found that a given degree of alkalinity

proved more effective in changing the viscosity characteristics of all
starches tested than an equal degree of acidity.

Harris and Banasik (2 ) exanined the effects of acne electrolytes
on cereal starches during preparation and gels inization. Test were
conducted with several laboratory-prepared wheat starches and one COLKCT-
cially manufactured cornstarch. Their findings indicated that chenical
treatment during the freraration of the starch had a marked effect upon
the starch grogerties. Treatnent with haCE raised the pH of the dry
starch and greatly increased the swell'ng rower. Ere;aration with E2305
lowered starch pH and increased swellinr power very slightly. Exposure
of wheat s arch to dilute solutions of ESL also lowered the ph and aug-
mented the swelling rower. Cooking in the presence of acid greatly
increased granule swelling at temperatures of five C and above. Suspen—
sions containing XaCE increased swelling at a teuperature as low as 7oo C
but at 93c C exhibited a lesser degree of swell than the acidified sus-
pensions. Harris and Banasik concluded that the presence of electrolytes
complicate the yroblens involved in the gelatinization of starch granules.

hains (21) reported that additions of citric acid decreased the
viscosity of cornstarch pastes nade with no suyar or with 2o per cent
sugar. However, in tastes made with As and SO per cent sugar hains pre—
sented evidence that acid did not neasurably decrease viscosity. She fur—
ther concluded that the gel strength of cornstarch pastes, at all levels

of sugar tested, increased when the rastes were cooked with citric acid.

A

Concentration of Starch

The work of Bechtel and Fischer (7) on the effect of starch con—

centration on viscosity verified the findings of Anker and Geddes (3).

FA
\Jl

Their findings indicated that each increxent in concentration resulted in
a greater increase in apparent viscosity. As the starch concentration
was increased, the following changes associated with gelatinization were

noted: 1) initial viscosity rise occurred at successively lower temperatures;

3) the rate of viscosity rise was sore rapid; 5) aaxiaum viscosity occurred

at lower tenperatures; and A) the decrease in asparent viscosity on con-

tinued cooking was nore rayid. Lowe (52) stated that reductions in viscosity

of cooked pastes, resulting from the rupture of swollen granules, was

greater with a 20 than with a 10 or 1} per cent concentration of starch.
Brinhall and Eixon (10) confirued the fact that, beyond the point of a

critical concentration of starch, eacn increase in concentration resulted

in encruous increases in viscosity and rigid‘ty of the resulting pastes.
‘ffect of Time and Temperature

Caesar and hoore (14) studied the viscous and plastic changes of
several varieties of starch at a 20 per cent level of concentration.
Viscosity ueasurenents were recorded over a wide range in tetperatures
with a Caesar consistoneter. Their findings indicated that a definitely.
fixed and specific te perature of gelatinization for all the granules of
a starch is not ,redictable. Although the process occurred over a con-
siderable range in temperature, the majority of starch granules gelatin-
ized within a narrow range. They concluded that the length of cooking
time is an important factor since the range of gelatinization varied with
the rate of heating. Caesar and Foore agreed with Cstwald (55} in the
theory that the lowest temperature in the gelatinization range should be
accepted as the gelatinization point of the starch under given conditions
of cookinc

Q and concentration.

Aleberg and Rash (2) regorted findings concerning the gelatiniaa—
tion of ooze connercial cornstarches by heat. In 4.} to 3 per cent concen-
trations of cornstarch in a water medium they found no significant changes
in viscosity up to 630 C. Between 63° and 6&0 C viscosities began to
increase gradually and at a uniforn rate. laxinum viscosity was reached
at 910 C. They attributed these increases in viscosity to siaultaneous
and gradual changes in the starch grains over a temperature range 0“ 350 C.
Alsberg and Rask concluded that th gelstinization teiyerature is not the
temperature at which gelatinization is completed but only that of an early
part of the process. As a result of their studies, hese investigators
offered the following observations concerning the gelatinization of starch:
(l) sharply drying or thoroughly wetting a starch rodified the gelatiniza~
tion temperature, (2) gelatinization was incomplete unless aiequate quan—
tities of water were available, (5} the rate of heating had a garhed effect
on the starch gelatinization tcnoerature.

Lowe (53; stated that starch nay swell to a certain extent at lower
tangeratures, but it does not reach Laxirun viscosity until a h’gher
tergerqture is attained. The tezgerature of L3XlRUK viscosity varies

with the satple of starch. She regorted :axinun viscosity texperatures
for wheat as 930 C and corn as 910 C.

As early as 1925 ileberg (1) reported that starch granules are
capable of swelling in cold water but are restrained fro: doing so, beyond
a certain linited degree, by the anatomical rigidity of the granule
structure. When this rigidity is relaXed by heat, the granule substance
swells further. Aleberg suggested that the ease with which the granule

structure is softened by heat and the extent to which heat will cause

swelling are influenced by the inherent swelling power of the starch
granule and the relation of the mass of swelling substance to the surface
area of the granule.

The findings of Anker and Geddes (5) erphasiaed the in;ortance of
raintaining a uniforn rate of heating throughout th- gelatinization
process for consistent results. Starting te yeratures exceeding 4) C
resulted in a substantial increase in naximum viscosit".

Bechtel (5) reported that viscosity curves indicated that rapid
heating lowers the tenyerature of the initial viscosity rise and decreases
the tine required for holding starch pastes at soc C to reacn taxinun
viscosity. From his findings Bechtel reasoned that there appears to be
a temperature for each starch at which it gelatinizes ra;idly and at which
subsequent breakdown is slow. For unhodified cornstarch this was about
940 C. This data has been verified by other authors (5, 53). Eisno (9)
recommended that rapid heating to the Optimum temperature and quick removal
of the starch {aste fron the cooking kettle, followed by rapid cooling was

neat conducive to the {reduction of Laxiaun viscosity in connercially

produced pie fillings.
foect of Fatty Acids

According to Schoch (4d), some of the {hysical differences between
tuber and cereal starches are ascribed to the lresence of f tty acids in
the latter. Cornstarch gastes are snorter, less sliny, and aore opaque
than sattes frOL tayioca starch. Schoch (4e) found that s gaste frou a
3 per cent concentration of raw rice starch required a niniuun aging period

of 24 hours to give a weak gel, whereas a sinilar paste of defatted rice

starch set up a strong gel ilhfldlilfi.f ugon ooo.lng to roe; truftrdture.
He concluded that when unmodified starch was defsttsd, tho asxiuuh 'is—
cosity was lowered to agfroxisately jJ yer cent of the oririnal starch.
These findings were later verified by Bechtel (i).

Whistler and Snart (b3) stated thit fatty acids were first thought
to be combined with the carbohydrate but were later found to be rarely
adsorbed on the carbohydrate and were congletely reaoVable by acid
hydrolysis. lows (53) consented that fatty acids were found in the auy~
lopectin fraction of starch. rotato starch was r go ted to contain no
fatty soils, whereas corn and rice gossessed a relatively high yercentage.
Whistler and Seart (4}) indicated that waxy cornstarch contained only
u.o6 per cent fatty substance.

Jordan and associates (37} cottared the viscosity of cornstarch
guddings sale with hangon'oed and Eon—LbhoiuhlJtd Lilh. Using a Brook—
field viscosiuotor, they found that yuddin s containinj a concsn ration
of corns.arch in excess of 5 ter cent were tore viscous when made froL
honorenized si.k than when made fros non-horogeniscd silk. The inVosti-
Qators reasoned that these differences in viscositios ti'ht be influenced
by the cotparative surface area of the fat flobules in the two Varieties

of silk tested. Jordan and co-worntrs concluded that fatty haterials

i.e. soaps, fatty acids and as ural fats}, when broeent in certain pro-

A

/\

portions, produced an increased viscosity in starch tastes.

The effect of nonfat dry silk soliis on the viscosity and ,el
strength of starch pastes were studied by iorse and tor co—workers ($4).
They used the Sterner viscosixeter to neasure the viecouitv of thin

pastes and a Bloon feloneter to measure the ~£l siren th of thicx tastes.

They found that nonfat dry rilk solids did increase the viscosity and gel
strength of gastes in gro,ortion to th aaount of dry Lilk solids used.
Verse and co-workers were able to sake limited predictions from their data
concerning the gel strength of rixtures containing different troyortions
of dried silk solids and thickening agent. These workers suggested that
salt, in the a cunts used in this (ngriuent, had little or no effect on
gel strength. However, in the thin pastes the HaCl did increase the

viscosity to a stall degree.

“ffcct of Sucrose

Starch chenists have long recognized the a,garent changes in the
behavior of the starch granule when starch is cosbined with aterials
other than water. The effect of sugar concentration ugon the quality of
the finished groduct “as been a challenging problem to these inv st'5ators.

In 1931 floodruff and Xicoli (45) ex;erisented with j per cent sus—
pensions of corn, wheat, rice, ,otato, and cassava starches with varied
proyortions of sucrose. At that tire no satisfactory methods of Leasur-
ing viscosity or gel strength had been established. The conclusions of
the investifators were drawn from changes observed in atgearance and
photographs of changes in pasting. The addition of 10 or 53 {er cent
sucrose produced increasingly softer gels in root starch paste‘. The
addition of 50 or 6o per cent sugar troduced a syrup. The ease percent-
ages of sucrose were added to the cereal starches. These gels were acre
transparent and tender with each increase of sugar. The addition of 50
{er cent sucrose groduced a gel which would not told successfully and the

addition of 5’ per cent sucrose produced only a syrupy, viscous L888. Cn

[-

Llcoli sseculated that the :resence

5
L

the basis of these data, Voodruff and

t

n L -

of large anounts of sucros prevented the starch granules iron inbioing
the water required for swelling.

According to Trempel (44), the addition of sugar raised the gelatin-
ization teayerature of a starch and water sustension. be verified the
findings of Noolruff and Iicoli (48) concerning the effect of high con-
centrations of sucrose on the swelling of starch granules. Treapel
recoutended that the progcrtion of sucrose huOUlj not exceed three and
one-half times the axount of starch used. He rcgorted that seven to eight
rounds of sugar to one gound of cornstarch in a S"ccific volune of water
resulted in a cooled gel which was dull, thin and tosseosed a raw starch
taste when preysred under ordinary conditions.

Raine 31) tested the ViSCOLCtriC effect of 2c, 4c and 5s per cent
sucrose ccncentrati as in la yer cent cornstarch wastes. dhe found that
viscosity increased when sucrose constituted 30 yer cent of the liquid

we'rht. however, with additions of A; and GO per cent sucrose, the :axinua

h
(D

ented evidence

(

viscosity of the {dates progressively decreased. Fains pr
that higher tetgeratures and nuch longer cooking yoriods were needed to
obtain uaxinun viscosity when increased sroycrtions of sucrose were added
to starch gastes.

Ferree (17) studied the effect of the concentration of sucrose on
the viscosity of cornstarch ,astes Lade with different liquid mediums.
She used sucrose in proportions of o, 15, 21, and 27 per cent of the
weight of the liquid. The liquid mediums used in her research were tap

tuted nonfat dried silk solids, and recon—

Ho

water, distilled water, recons

stituted whole dried rilk solids. Ferree refortcd that, exceyt for the

[\J
H

paste cade with whole dried silk solids containing 21 per cent sucrose,
the Laximuu viscosity of sweetened and unsweetened pastes cade with tap
water was higher than that of sinilar pastes uade with other nediuus. In
all cases naxinun viscosity of those pastes made with whole dried silk
solids were appreciably higher than that of pastes made with distilled
water. Results of these tests showed the descending order of maximum
viscosity for these nediuas to be tap water, reconstituted whole dried
silk solids, distilled water and reconstituted nonfat dried silk solids.
The observations of Raine (21) and Ferree (17) indicated that the
effect of the proportion of sucrose on the viscosity of cornstarch thick—

ened pastes cannot be accurately predicted without taking into consider-

ation the proportion of the other ingredients used.
Gel Properties

Lowe (53) has stated that there is no distinct line of separation
between a sol and a gel. A typical sol is fluid; a typical gel has a
certain anount of rigidity. Gels are unique in having a dispersion
medium which is still liquid but is held in the gel state by the ciscelles
foraing a definite structure. Gelation is a function of contraction and
the volume of the dry micelles plus that of the dispersion medium is
greater than that of the two combined. The degree to which a specific
starch paste gels on cooling is a primary concern in the food industry.

The literature contains numerous references concerning differences
found in the properties of hot and cold starch pastes. According to
Bechtel (5) the prOperties of starch gels depend upon the natural variety

of starch, treatment during nanufacture, and all conditions to which the

H.)
h)

starch is subjected lvrin; cocking. Eechtel conducted tests on unhodified
cornstarch suepensions by heating them to 910 C. The resulting pastes were
poured into uolds and stored in a 250 C water bath for 24 hours before

they were tested for gel strength. The data of Bechtel presented evidence
that the percentage increase in rigidity and breaking strength of gels
during aging was dependent uyon the codification of the starch. The acid-
nodified starches which had been cocked to 910 C and cooled to room temger-
ature exhibited greater increase in rividity and breaking strength than
did the unLoiified starches whlcn had been piven identical treatnent. The
effect of final cooking temperature of starches on the troperties of their
gels varies with the derree of nodification of the starch. The findings

of Bechtel indicated that, with ihcreased modification of the starch, the
viscosity of the acid—'odified cornstarches decreased to a greater extent
than did the rigidity and breaking strength of their gels.

Hoodruff and Raclasters (47) found tnat there was no relationshio

O

s

between the consistency of hot pastes of unusdifiei cornstarch and the
properties of its gels. It has been established that when cornstarch is
oxidized, rigidity and breaking strength of gels decrease more than does
hot—paste corsisten y. These investigators proved that acid-xodifiei
cornstarch produced a s alfier decrease in rigidity and breaking strength
than in viscosity. Woolruff and Nicoli (LE) experimented with various
tuber and cereal pastes at a 5 per cent starch-to—water concentration.
They reported that naxinun gel strength was obtained in each starch

when it was cooked to a tetperature of 9pc C or higher. The cereal
starch gels were well-formed and had clearly defined outlines, whereas
the tuber starches gave poorly forned gels. Eisno (9) verified the

findinrs of Woodruff and Hicoli.

.)

hnowles and Harris <5J) observed the behavior of starch gels
fro: different classes and varieties of wheat. They concluded that SJC C
was the critical temperature for gel forration for j per cent starch
suspensions. These investigators found that gels never forned below
this temperature, that gels sowetires failed to form at Duo C if the
conditions of gelatinisation were not ideal, and that the resulting
gels were usually weak and displayed evidence of syneresis. They
further decided that starches derived frog soft wheats possess lower
gel strengths than those prepared frcn hard wheat.

Throughout the starch industry it is a r

‘3

nerally accegted fact that
:rediction of cold waste consistenc‘ of a starch fron its hot aSLC vis—
t’

cosity is ingossible.
Effect of Batch Size on Flow Properties

The literature contains resorts of relatively few studies in
which differences in starch behavior attributable to batch size have
been considered.

Billin:s and associates (5) experixented with cream pie fillings
prepared in multiples of an C—pie batch. Fron preliminary tests the
investigators found it necessary to uodify the hultiple of the forzula
by increasing the amount of soft wheat flour required to produce fillings
of acceptable consistency. Using the E-gie batch of pie filling as a
base, the workers increased the flour 10 per cent for the lS-pie and 24-yie
batches and 53 per cent for the 53—pie batch. According to Billings
and associates, the increase in proyortion of flour to liquid was necessary

to cenpensate for the reduced thickening effect of the flour. Factors

contributing to this reduced thickening power were slower rate of heating
and lower final temperature as the batch size was increased. The radius
of spread of hot fillings was considered a reliable and practical measure-
ment for predicting the consistency of the final product. These workers
reported that they found subjective tasting for the disappearance of raw
starch flavor a more reliable criterion for determining the end point of
cooking than final temperature or time of cooking. Billings and co-workers
concluded that both final temperature and tine were directly dependent
upon the rate of heating.

Longr‘e (51) investigated the effect of increasing batch size from
1 to 4 gallons on cooking tine, tenperature of batch, and final viscosity
of medium white sauces. The white sauces, designated as uedium thick,
contained 8 ounces of flour per gallon. Tests were made using all-purpose
flour and soft wheat flour. The soft wheat flour displayed a-greater
thickening power than the all-purpose flour. With increasing batch size,
the length of cooking tire was increased and final viscosities of the fin—
ished sauces decreased. Differences between the l- and d-gallon batches
were slight. The cooking time in the_4-gallon batches was unduly long and
final viscosities were below the standard of control. Longrée consented
that the additional stirring required during longer cooking may have been
partly responsible for the low viscosity of the large batches.

Caesar (15) stated that batch size does have a tredendous effect
on the properties of starch pastes and also of dextrins with the possible
exception of the most highly soluble envelope type. In addition, Caesar
suggested that the length of the heating period and the temperature of the

paste may be relative to batch size but that the cooling period is even

t x)

\,l

more important to the paste characteristics of starch than the heating
period. Agitation plays an inportant role at all tines and eagecialiy in

the cooling process of starch pastes.

Objective Tests for Starch Pastes

The principle uses of starches in industry are iirectly detendent
upon their colloidal paste progerties. Sone of the characteristics of
cooked starch pastes are viscosity, plasticity, gel strength, and rigidity.
These characteristics are ueasured in terms of hot paste viscosity and

cold taste body.

Viscosity neasureyents

 

Industry has developed several proceiures to test viscosity of
starches. heae objective reasurenents are nade on both hot and cold

pastes.

Scott test for hot gaste viscosity (38). This test is grohably the aost

 

 

widely used s-thod for detertining the hot paste viscosity of starch
pastes. A quantity of starch at known pH is stirred to a slurry with 250
cubic centimeters of distilled water in a German-silver beaker. The
beaker and contents are then placed in a boiling water bath in which, with
stirring, the starch is gelatinized and heated for 1) Linutes. Two min-
utes preceding the end of the cooking period, 300 cubic centimeters of

the paste are transferred to a Scott viscosity cup which is also held in
the water bath. At the end of the total heating period, the plunger valve

which closes the orifice on the bottom of the cup is raised and the time

[\J
0.

in seconds is noted for a given volume of the paste to fall into a grad-
uated cylinder. The specific Scott test viscosity value of the starch
paste under consideration is measured in terms of the seconds required
for the starch to flow from the test cup.

Standard starches are used to set up peruissable limits of varia—
tion in the viscosity of other starches to be tested by this method. Scott

test viscosity nay also be considered as a relative viscosity in this sense.

Storuer viscosiueter (BE). This instrument is used to evaluate the viscos-

 

ity of cold paste body. It is comprised of a cylinder immersed in the test
paste which is contained in a metal cup surrounded by a water bath. The
innersed cylinder is rotated by a free—falling weight acting through a

gear and pulley systea. The time in seconds necessary for a given weight
to produce a certain number of revolutions is taken as a Leasure of cold
paste body. A revolution counter is a part of the instruaent.

The starch is gelatinized and cooked for a lj—ainute period. The
paste is placed inuediately in a constant temperature water tath, prefer—
ably 250 C in a closed container. At the end of a specified aging period,
any surface skin on the paste is carefully renoved and discarded. The
reraining paste is very gently stirred with a spatula for several seconds
and then transferred to the cup of the Storner viscosiaeter. The viscosity

of the paste is noted at 25° C.

Hoeprler viscosineter (25). This instrument involves the use of a prin-

ciple different from that of the Storaer viscosineter. Feacurements are

nade of the time required for a given weight to fall, in vertical notion,

)

through a measured column of paste. The colurn is surrounded by a constant

temperature bath so that, with only slight modifications, the instrument
can be adapted to the seasureaent of hot paste viscosity as well as cold

paste body.

Brookfield Visccsi eter (28). This is torsional type of instrument.

 

Spindles of various types are driven by a synchronous actor. The force
of the thickening starch paste, acting on the spindle, is recorded in

terms of poises and is taken as a Leasure of the viscosity.

Brabender anylograph (25). This instrument is a conparatively complicated

 

one. It is a uodification of the Brookfield viscosineter but involves the
same general principle. In this nethod the paste is held in a cup sur-
rounded by an air bath for enperature control. The cup is revolved at
constant speed. The measuring and stirring device consists of a disc to
which are attached several short rods extending into the paste. The torque
impressed on the Leasuring unit is transmitted to a recording torsion
balance. A continuous, graphical record of the gelatinization process is
traced by the instrument over the entire period of the test. The tenperature
of the starch may be increased at a fixed rate and say be checked at any
point and held at this level by thermostatic control. By switching off the
heat supply, the paste may be cooled to any desired temperature and the
change in viscosity noted.

A cooling coil is provided for the circulation of cold water and the

acceleration of the cooling of the cooked paste.

Caesar consistoaeter (28‘. This instrument may be used to ueasure several

 

characteristics of starch simultaneously. This apparatus records a contin—

uous history of the pasting operations. Characteristics of the starch paste

{u
f‘vfl

which ray be evaluated fron this record include the gelatinizaticn point
of the starch, peak viscosity obtainable with a definite cocking procedure,
specific viscosity after a prescribed cooking Operation, rate of increase
in paste body with falling tenperature, and cold paste body after a con-
trolled ccoling period. For the test a standard paddle, connected by a
shaft to an electric motor, is suspended in a beaker containing the starch
slurry. The beaker is surrounded by a heating bath, and the teaperature
is raised at a regulated rate. The paddle and actor move at constant
speeds. C.anges in paste body are indicated by the differences in the
electrical input to naintsin a constant Lotor speed. After the starch is
cooked, cold water say be introduced into the bath to cool the paste.

Caesar and hoore (14) reported that the principle function of this
instr*nent is to neasure the viscous and plastic changes in starch pastes
at any temperature at relatively high concentrations. They stated that
significant differences in observed values were more readily obtained with

n

a 2o per cent starch solution than with starch solutions of lesser

concentrations.

Corn Tpdpgtries viscoueter. healer and Bechtel (29) used this instrument

 

in their work on the couparison of tne flow properties of different type
starches. They felt that this instrument provided a controlled and repro-
ducible nethod for pasting as well as a record of the change in consistency
as cooking progressed. The instrument consists of a stainless steel beaker
innersed in a theruostatically controlled bath which contains water or a
liquid with a higher boiling point. The starch slurry is stirred by an
agitator which consists of a scraper and a propeller. The scraper serves

to remove the layer of pasted starch from the walls of the vessel. The

[\J
\L.

propeller, driven through a gear differential, stirs the center of the
paste and also serves as a Leans of measuring the viscosity changes. The
force which the propeller encounters is continuously balanced by a dyna-
mometer, consisting of a weighted arm which roves through a vertical are.
A series of interchangeable weights are provided for the dyiaaoneter so
that it covers a relatively wide range of torques between 230 and 2000
gram—centiaeters. The pen, which is attached to the dynanoaeter, contin-
uously traces the record of viscosity changes on a strip-type recorder.
The cover acts as a condenser and prevents evaporation of water from the
paste during the heating period. The viscosity changes of the paste are
recorded in terns of torque which is the neasure of the force the propeller
encounters as it turns through the gelatinizing paste.

To make a deterhination the metal beaker is placed in the preheated
bath and the stirring device is attached and set in notion. The starch
paste is prepared by stirring the starch into the quant'ty of water needed
to yield a slurry of 1:00 grass. The water should be at room teaperature.
The slurry is poured into the viscometer and the recorder is started inne-
diately. The condenser cover is then put in place and the remainder of the
test is accomplished autohatically. Readings of the paste temperature at
desired intervals are easily obtainable from the strip—type recorder chart

which unwinds at a constant speed.

Line-spread test

 

"\

Graweheyer and Ffund test. Graweaeyer and Pfund (2o) have developed a

 

line-spread test for deteraining the flow of cooked pastes. This test is
effective in measuring the spread of both hot and cold samples. Graweaeyer

and Ffund Lads objective neasurements on applesauce and cream fillings.

Longrée (51) used this type of viscosity measurement in her comyarative
study of thin, rediun, and thick white sauces.

In this test a flat glass plate was placed on a surface checked for
evenness with a spirit level. A diagram f concentric circles was placed
beneath the glass plate. The diaaeter of the arallest circle was 2 inches
and the gradations of the surrounding circles were at one—eignth inch
intervals. A hollow cylinder of the exact dis eter cf the ChallCSt circle
was used to hold the poured sample. This cylinder was placed directly

over the inneraost circle, illed with the paste to be tested, and then

levelel with a spatula. The cylinder was lifted carefully and the Bakple

allowed to flow for two minutes. Readings were taken at four widely separ-
ated points which designated the outer lisits of flow of the sample. The

average of the four readings was considered the value representing the

Line-spread of the gaste.

‘

n 1 a
gel strength tests

 

A variety of instruments incoryorating different principles have
been used for the measurement of the gel strength of starch wastes. herr
(BE) stated that several 9 the instrurents used in practice are the
ri7idOT¢tCF, Tarr-Baker jelly tester, and the penetroueter. The rigid-
creter weasures the rigidity or lack of elasticity of a gel. The Tarr-Baker
jelly tester gives a value which is proportional to the force necessary to
rupture the gel and which say also be a function of the elastic lizit.

PCECtFOLcttFS are of two types. The blunt plunger type tests a ccabina-

”CT measures

1'
*—

tion of plastic and elastic effects. The tube type of plun

the resistance of the gel to cutting'action.

[1]

xchsnge Ridceliaeter (15). For this deter1ination the paste sanslec

 

are stored in jelly glasses provided with sideboards. At the end of a
controlled aging period, the sideboards are removed and the saaples
leveled to the rim of the glass. Each sample gel, after resoval fron

the glass by inverting it on a glass plate, is allowed to stand for two
minutes. A sicrOueter screw is adjusted and the per cent of sag is read.
This test measures the rigidity of a gel in terms of percents

e of sag.

.-.
,1
.‘ a.

Tarr-Baker jelly tester (25‘. The grinciple of this test is the gradual

 

application of pressure to a plunger of known area which rests upon the
surface of the gel. The pressure is read the instant that the gel breaks.
In this test the starch slurry is placed in a porcelain cup and

cooked in a boiling water bath for 50 minutes. The cooked paste is cooled
quickly, immediately covered with a film of light nineral oil, and aged
for one hour in a water bath at 2&0 C. The oil is drained off and the gel
is placed under the plunger of the tester. With Boo cubic centimeters of
water in the testing jar at the start, the flow of water is adjusted so
that the manometer column rises 5o cubic centimeters per uinute. The Lan-
ometer is read when the gel breaks. Tests are made in triplicate and

1

readings are averaged. The gel strength is reported as the height in
I

centimeters reached by the liquid in tle nanometer at the breaking point

of the gel.

Kerr modification 2; Saare and lartens test. One of the first tests tro—

 

 

posed for the reasurexent of gel strength of a cold paste was developed
by Saare and Eartens. This test consists of deternining the weight re-

I

quired to withdraw a disc from a gel in which it has been igbedded. A

u -r

\N
{\o

modification of this method by Kerr (if) is used frequently. In this
test the hot, cooked starch paste is innediately poured into a glass
container to a definite level. A circular natal disc of known disaster
is susgended into the paste by means of a metal rod connected to the
center of the upper surface of the disc. The natal rod is crooked at the
top and is hung over a bar which rests on the top edges of the container
holding the sample. The length of the rod is such that, when it is sus—
pended over the horizontal bar, it percits immersion of the test disc in
the paste to a depth of three centimeters. A thin film of light oil is
placed on the top of the paste as soon as the disc has been inserted and
properly centered. The test vessel is held in a constant tangerature
bath at 250 C for 24 hours. The test container is then removed and
placed on a bridge over one pan of a large, sensitive bean balance. A
specially made hook, suspended from this bean, fits into the bend in the
rod attached to the disc. Small size shot are added at a fixed rate to
the other pan. The weight of shot is noted at the ties when the disc
fractures the gel. ne wsifht of shot, less the weight of disc and all
connections to the bean of the balance, divided by the exact area of the
lower surface of the disc is taken as the gel strength. The result is
expressed in grass per square centimeters for a given concentration of

starch.

Fuchs genetroneter. hcrr (2E) reported that most penetroseters are not
sufficiently sensitive to distinguish between the various grades of
acid—codified industrial starches. however, Kerr admitted that the in-

strument constructed by F. W. Fuchs is as sensitive and accurate as the

nodified Saare nethod of deternining gel strength. The cooked starch

$5

paste is in eiiately ylaced in a closei, wifie-touthei container for
storage in a constant tetgerature bath. At the end of a specified aging
period tLe cover is reLoved and about a one-fourth inch layer of gel is
cut off and discarded. The glunger in this instruzent i: a highly
polished, sharpened, follow Leta} tube wLich reserblee a cork borer. This
{longer is adjustei so that it rests on the top surface of the gel. The
plunger is released and the time required for the hollow tube to cut the

gel up to a predeteriined depth of paste is noted.

IROCEDCRE

Developnent of Testing Equipnent

Several pieces of specially designed equipment were necessary in
developing a technique to detertine the spread fret a cut sanple of
cooled chocolate pie filling.

A glass plate 12 x 12 x .25 inches from which a circle 9.575 inches
in diameter had been removed was superinyosed upon a second glass plate
12 x 12 x .25 inches. These two plates were bound together by four rubber
bands 5 x .575 inches. One rubber band was mounted one half inch from each
side for the purgoee of binding the plates together with an equal distri-
bution of tension.

A mold was devised from a standard metal baking pan 1.5 inches high
and 9 inches in disaster with a circle 7 inches in disaster renoved from
the bottou. Before the hot sample was poured into the mold the pan was
inverted and placed within the 9.575 inch cut-out area of the Upper glass
plate.

The round, stainless steel sample cutter was constructed with a
diareter of $.12} inches and a height of 1 inch. An outer band of Letal
.573 inch wide and .QGB} inch thick was welded .35 inch from the top edge
of the cutter to form a base for the expansion band.

The round, stainless steel expansion band was constructed with a
diameter of 5.25 inches and a height of .7} inch. When mounted in place,
the expansion hand rested upon the .U62j inch ridge formed by the thick-

ness of the outer band of the SSKUIB cutter. The cutters and their res ec-
l

tive expansion bands were hatched and coded.

Nine con Tote sets of the testing eguigaent described above were

L

required for each replication of this experinent.
.

Basic Fortula

The foraula erd in this linited exgeriaent was developed through
prelininary study of products saie roa selected fOFLUluS in which corn—
starch and cocoa powder were used as thickening agents. No formulas in
which whole egg or egg yolk constituted a part of the thickening effect
were considered.

The selected fornula consisted of constant groportions of cornstarcn,
whole dried Lilk solids, cocoa powder, granulated sugar, butter, salt,
vanilla and cold water. Proportions of ingredients for all batch sizes
tested are listed in Table 9. Percentages of ingredients, based on the

total weisht of the nixture, follow:

 

 

Infircdients reroentagee

Cornstarch 5.8 O
dhole dried m lk soiids }.o

Cocoa powder 5.8

Sugar l€.6

Butter o.C

Salt v.1

Vanilla u.E

eater, cold __:2L;‘

TOTAL lJo.l

Cold water, in which the natural degree of hardness had not been
sutjected to alteration by the addition of chemicals, was used for this
study. A sanple of water used in eacn replication was sent to the labora—
tory of the College Sanitarian for analysis of the degree of hardness.

All renaining ingredients, except butter, were obtained from the

College Food 3tores and stored at room temperature throughout the study.

The cornstarch and the superfine granulated sugar were kept in

Q

separate, covered, stainless steel sins. The cocoa powder and iodized
salt were stored in their original fiber containers. Spray process Parlac,
nanufactured by the Borden hilk Conpany, was the type of whole dried silk
solids used throughout this exp'riuental work. The entire lot of Parlac
was purchased in five pound, heruetically sealed tins.

Imitation vanilla was purchased in four l-gallon glass jugs from
the sane case lot and was composed of vanillin, caramel, water, propylene
glvcol and 0.1 per cent benzoats of soda.

Butter, in chiplet form, was obtained from the College Dairy and
stored in a deep freeze unit.

It was necessary to transport the ingredients from the laboratory
to the institutional kitchen for the cooking frCCBSS. All ingredients for
each batch were weighed or Leasured in advance. The sugar, cornstarch,
and cocoa were put into separate, brown paper bags and the bags were fas-
tened with freeser tape; the dried nilk solids were weighed into a poly-
etheylene bag and fastened; and the butter, salt, and vanilla were placed
in separate, covered, plastic containers. No ingredients were weighed or
aeasured for more than two weeks in advance of their intended use. During
this interval, with the excettion of the butter which was returned to the
deep freeze unit, the weighed ingredients were keyt in dry storage at

room teaperature.

Treatnent

Cold water was heasured into a hO—gallon steam jacketed kettle and

heated to a teaperature of ")0 C. This kettle was equipped with an

“\J

\N

Ashcroft 50% pressure gauge and the water was heated by steam with a pres—
sure range of 16 to 19 pounds.

A centigrade thermometer was suspended in the kettle in such a
asnner that the bulb was centered within the mass. Adjusttents in the
tosition of the thermometer were necessary in relation to batch size to
insure comparable readings. This thermometer registered the temperature
of the mass during LLB entire preyarstion period.

The whole dried silk solids were blended manually with approximately
one half of the sugar. This sugar and milk dry mix was scattered on the
surface of the water, which had been heated to jio C, and blended with a
french whip. After thorourh blending, the mixture was allowed to stand 3“
minutes to allow tine For reconstitution of the dried milk solids. Tine
required for blending the sugar and silk dry nix with the water and any
change in tenperature noted during this Procedure were recorded.

The cocoa powder was sifted and then blended for 10 Linutes with
the cornstarch and remaining portion of the sugar with the paddle attach-
ment on a 5—speed nechanical sixer operating at first speed. At the end of
the 20 minute reconstitution period for the sugar and milk mixture, the
dry mix of cocoa, cornstarch, and sugar was scattered on the surface of the
sugar and Lilk solution and stirred ranually. The time required for this
addition and the final temperature of the mass at this stage were recorded.

The steam was turned on and the mass was heated to 520 C, with fre-
quent, :oderate stirring. Steam pressure of approximately 16 to 19 pounds
was maintained throughout the cooking period. The temperature of the ease
and the pressure poundage of the kettle were recorded at 2-minute intervals.
The first visi le evidence of thickening within the mass was noted in

relation to the heating time required and the temperature attained.

The end cocking temterature was arbitrarily set at 630 C. When
this {oint was reached, the stean was turned off and the butter, salt
and vanilla were manually stirred into the uses. The time required for
this blending and the acconyanying tengersture change of the K338 were

recorded.
Batch Size

Batches were prepared in 14, 12, 10, t, and 6 gallon amounts. An
end cooking tenterature of 82° C was kept constant for all batch sizes.
After the incorporation of the butter, salt, and vanilla, the holding
periods of the mass in the steam jacketed kettle remained constant for
all batch sizes.

There were four reelicaticns for each hatch size indicated above.
Pre,aration of Samples

In this investigation it was the intent of the worker to determine
the effect of batch size uton the flow of chocolate pie filling under con-
ditions which most nearly paralleled current quantity food preparation

practices. Since chocolate tie is cost frequentlv served at room temper-

U

ature, it seemed more realistic to measure the flow of a sample cut fron a

molded anount of cooled fillin: than from a sample of hot filling.

L.

Pourinz 2: sold. The hot filling was removed from the kettle at the end of
each of the stipulated holding periods in an acount sufficient to gour 5
molds of 5 pints each into stecially desifned netal colds which had been

adjusted upon the double glass plates. The 5 colds within each series were

\N
\C‘

poured at l—ninute intervals and coded in the order in which they were

poured. Nine molds from each replication were poured as follows:

 

 

Sex-153 go. of 5:1wa rinuggseld at 62° 5;
A 5 o
B 5 50
c 5 60

Through preliuinary work on the technique of pouring and handling
the filling, it was found necessary to devise a method to prevent the
formation of a heavy "skin" layer on the surface of the poured sold.
Neither Saran wrap nor absorbent paper alone offered sufficient protection,
but their combined use served this purpose adequately.

After the filling was poured through the opening of the netal mold,
the opening was covered with a double thickness of absorbent paper plus an
outer layer of Saran wrap. he poured nolds were allowed to cool undis—
turbed for 5 hours at room teaperature. From this point, the individual
molds within each series were handled at 7-minute intervals. This resulted
in progressive cooling periods of i hours, 5 hours 7 minutes, and 5 hours
14 ninutes, respectively, for the 5 colds of each series. The order in
which the individual molds of the Series A, B, and C were poured established

the sequence in which the molds were handled throughout subsequent testing.

Cutting thg §§y§g_. At the end of the cooling period, the rubber bands

were carefully severed to release the tension on the glass plates. The
layer of Saran wrap and the double thickness of absorbent paper were removed
in a single, swift operation. Since there was evidence of excess noisture

trapped between the absorbent paper and the Saran wrap during the cooling

~+L

period, care was taken to prevent the condensate fro: draining back on to
the surface of the aolied filling.

The cutting edge of the seafle cutter was lubricated by dipping it
into salad oil. The excess oil was removed with an absorbent paper towel.
This step was necessary to lessen the resistance encountered when the
cutter came into contact with the filling. Cne sample was cut from the
center of each mold of filling. After the sanple cutter, complete with
expansion band, was inserted into the molded mass, the upper glass plate
was elevated and renoved. Next, the metal mold was removed.

with the cutter still in position, the excess filling around the
outer edge of the cutter was removed with the aid of a rubber squeegee
and a conson household rubber scraper. A dang, lint-free cloth was used
to renove any renaining fila from the glass plate. The eXpansion band
was then remove from the cutter and the sanple was leveled, by means of
a thin—edged utility knife, to a constant depth of 1 inch. This depth was
equal to the height of the cutter without the eXpansion band.

The cutter was removed at the end of the sixth minute in the seven
rinute work period allotted for each sample cutting. This procedure re-
leased the sanple and allowed it to flow freely. Each sample was permitted
to flow for a period of 90 minutes before measurements of flow were taken.

All sazple plates were coded for series and sample cutters.

Recording the sample. The image of the sample was recorded by reans of a

 

photoflood lamp casting the shadow of the sample upon Technifax viazo blue
line paper. The photoflood laLp was inserted into a 9—inch uetal reflector
and mounted on a ring stand in such a tanner that the bulb was suspended

l2 inches above the upper surface of the glass plate holiing the sample.

The light.sensitive paper was placed in position under the glass plate.
The eXposure time was arbitrarily set at 2 Linutes and retained constant
for all samples.

The ammonia fuses required for the development of these inages
were obtained by heating household ammonia to louo C in a 9-inch stainless
steel bowl. The exposed Technifax paper was held manually in a horizontal
position approxitately 5 inches above the surface of the boiling ammonia
for a period of 2 cinutes. All iuages were developed within a period of

l) ninutes following the completion of the eXposure time.

Objective Measurement

In determining the amount of flow for each cut sample after the
99-pinute flow period, it was necessary to use an accurate neans of calcu—
lating the final area of the sample and the initial area of the cutter
used to obtain the sample. A compensating polar planineter adequately
served this function. This scientific neasureing instruuent was operated
manually to trace the circunference of the printed inaye. The recording
wheel autonatically presented the area aeasureaent in teras of sguare
centimeters.

To deterrine tne initial area of the saaple before it was released
for the 30—xinute flow period, he cutting edge of the sahtle cutter was
heavily coated with a red wax pencil. It was then pressed firhly against
a sheet of white aiueograph taper. This imprint gave an accurate outline
of the cutter from which the area was determined by the compensating
planineter.

The anount of flow for each sample was deterhined by subtracting

the area of the cutter fron the area of flow of the cut sanple. This value,

exoressed in square centimeters, was read to the nearest 0.1 square
centiseter.

The results of the spread tests for all samples were compiled for
four replications of each of the five batch sizes tested. This data was
analyzed to deterrine the effect of batch size and holding tine on flow.

Time-temperature curves, based on the average for each specific
batch size, were plotted. In evaluating the effect of batch size on flow,

these relationships were also studied.

Illustration of Technique

The development of the testing equipLent, preparation of the
samples, and the technique of objective measurement of flow of the cut
samples have been previously described.

The testing equipnent used in this research and the consecutive
steps in the procedure for pouring the mold, cutting and leveling the
eaaple, releasing the sample for flow, recording the image of the sample,

and aeasuring the sample area are illustrated in Figures 1 through 10.

amsopmorzzt-‘trht-‘tcmramuomzb

Key to Photographs

. .

ass plate 12 x 12 x .-) inches with circle removed
aetal sold 9 x 1.5 inches with 7 inch circle rezoved
glass plates bound together with rubber bands
Complete assenbly of holding equipnent

Pouring the mold

Saran wrap

Absorbent yaper circles

Stainless steel exp neion band for cutter

Stainless steel sample cutter

Asseubly of saaple cutter and exransion band
Inserting the sample cutter assembly

Removing of glass plate

Removing the metal sold

Recoving the excess filling from around the sample cutter
Leveling the cut sample

Removing the sample cutter

Ring stand and photoflood

Technifax diazo blue-line paper in position
Conpensating polar planimeter

lass plate 12 x 12 x .25 inches
1

“‘ (D L.)

3

Figure 1. Molding equipment: individual parts, partial and complete
assembly.

Figure 2. Pouring the mold.

 

Figure 5. Inserting the sample cutter. Individual parts and complete
assembly of sample cutter.

Figure 4. Removing the upper glass plate.

 

 

Figure 5. Removing the metal mold.

 

Figure 6. Removing the excess filling from the outer edge of the
sample cutter.

Figure 7. Leveling the cut sample.

P", ’r' "s-."yr‘.‘-'.'I_ ”’\‘,1’,-_'-.:"‘1
'-., a - -~\‘toq- q“! 3a,};
7‘9".“ '| ‘7‘v‘ \
J ' , , ~ ', -_ ,

.-
L's:

Figure 8. Releasing the cut sample for flow.

 

 

Figure 9. Recording the sample area on Technifax Diazo blue line paper.

 

 

Figure 10. Measuring the sample area with the compensating polar
planimeter.

“4/

DIJCUJSICE AID RESCLTS

Control of techniques used in the execution of this project were
as complete as possible in the procuction center in which the testing
was done. However, these physical linitatiors were taken into consid-
eration in 'nterpreting the findings of the study.

The steam-jacketed kett.e was a part of a battery consisting of
one j-corpartnent steamer, one braiser, and three :arge steam~jacketed
kettles. The source of steam was also connected to the pot and pan sink
in adlition to this cooking battery. The steam pressure for the kettle
used througnout this study was not thermostatically controlled. Con-
stancy of steam pressure was dependent ‘pon nanual adjust ent as indicated
by a gauge located near the point at which the steaz entered the base of
the kettle. hechanically controlled agitation would have cessurably
decreased the variables introduced by nanual stirring. The proxirity of
the kettle to an entrance of the building ostpiicated control of heat
loss and evaporation from the surface of the mass.

Production activities which were necessary for tne opera ion of
dorcitory food service were in progress during the cooking periods of this
experiment and made couplets control of physical factors extremely diffi—
cult. Production scheduling and the details of procedure were planned
by the investigator with the dormitory food service personnel in an
attempt to reduce physical and operational variables to a minimum.

This study was directed prirariiy toward the objective ueasurezent
of flow of cooled, cut as plea of the starch—thickened mixture prepared
in 6, E, 10, 12, and l4—gallon batch sizes. The treatment variable was

introduced at the end of the cooking process and concerned the length of

)o

time the mass was held in the kettle after it had reached a temperature
(a ‘ V . ‘ ‘ . ”flfi- I ~’

of 52 C. Three cacp.sc were tawen fret each replication at the end of
the s ecified holding periods of L, 50, and 50 minutes. Treatments,

3 1

based on the length of the holding period, were designated as Series A,

n

Series B, and Series u.
Cold Paste Viscosity Tests

The “zasuresent of flow for sahples, expressed in terms of square
centimeters, was deter inei by leasuring Teohnifax prints of he eanples
with a ocuicnsating polar planiteter. Averages for three readings for
each treatnent within each replication are shown in Table 1.

Two sarples in two different replications of the C-fisllon batch
were lost through breanage of the lower glass plate during the cooling
process. These Values were statistically talihdted and inserted in the
data (A). Replication three of the f—gallon batch size showed flow
readings for all nine samples which were relative within the renlication
but were not comparab;e to the flow readings of replication 1. 2, or 5.
The investigator felt that this extreue variability might have been attri—
butable to an error in the liquid ueauureuent of the formula. These flow
readings were not discarded but were statistically modified by the appli-
cation of the least uiuare method (4/. The insertion of these eleven
estitated values apfected five of the treat:ent averages.

An adjustment for total degrees of freedom was made in the analysis
of variance to correctond to the missing values shown in Table l. The analy—
sis of variance of the data, including three treatment averages for four

replications of each of the five batch sizes, is shown in Table 3.

sizes tested.

es of batch

’?
L
.2

f treatxent avera
(square ccntiaeters'

burnary c

‘

1
I

 

 

{It

--r~.—-———

 

.eatn

”w
‘. ..

 

ication

I
4

'5 .
o'xei"

Batch Size

flu

 

Q o (J. _)

—( ‘rL. I...V _)

.DzoIH.)

.4 727 .9
cc l/ .../ 3.
7.7. ..)/o

.)Z./\AI%
14).. ,JZU
1. ././.0C

11..

1i ). 2/-4

14 gallon

Awaia.;o

1i .../ 7/34

r) 3... 1...? _\/.

l.

«.5.

gallon

«1*.(/ 7..

. D C
7.. 7: CL
1/..A. {V

nu- .) ‘A
5 3H .1
{J n! .7/

aez/na

..U E C: CL

0 o O I
.. . .fi/ _/t 7!
2/14. 22.1w

3/51.;1.

2 9 TIA.
7/0 .) 7.

1). 1):“.

gallon

P

3.:
J

W); 11
c Kl 7 9.

.5, .1 5 z)

.2”
.14 ...../ 3. 2/
O 0 O 0
CL ./:4 1..
2/ z] 3.1/4.

1).
4.4.48

1,: 1... 7 .,\./
Au ,.3 1/ q/

ii)_K{4

gallon

8

v 3/7. l/
I.» c J.
l4. r‘/ 4/ 3.
/O .\/!4 r/
IV .N/ ..//
‘JHH. 7 ).

)9 1.. 1/5

.J/ 95/ .7 ....v/
71 , no _.\/ Ilia

xi)_37#

6 gallon

 

C
a...
D;
a
I”
$.v
C
0
vi
r
O o
0.. G
e
6 U
u.i
\l. a
a V
V
dd
GD .6
U .1
.l A:
S .l
8 .3
.1 O
M N
1 2

Table 2. Analysis of variance for flow.

 

Source of variance D.F. M.5. F.
Total j4
Replications } 345.4 7.5“
Treatment 3 o146.2 191.2"
Replication x Treatment 5 31.6 .7
Batch Size 4 leY.) 45.5”
Replication x Batch Size 12 :y2.4 9.1"
Treatment x Batch Size 8 j.) .5
Error 19 52.1

 

D
L

This analysis showed that there were highly signi icant d fferences

in flow attributable to replication, treatment, anfi batch size.

Production technigue. The effect of variance iue to replication was

 

analyzed within each batch size. A summary of these analyses is shown in
Table 5.

These analyses indicated that variance iue to replication was sig-
nificant in the 9, €, 10, and l2-gal-on batch sizes but showed no signifi~
canoe in the lh-gallon batch size. Inspection of the original data
indicatei that the flow readings for four of the nine pctred samples of
replication one in the lA—gallcn batch were extrecely high in relation to
comparable samples of replication 2, 5, or A. Failure to level samples

1, 3, 5 of Series A and sample 1 of Series B to a constant depth before

releasing them for flow resulted in unusually large flow readings. This

factor may have been great enough to affect the mean scuare value of the

5

error term in the analysis for replication for the lA~gallon batch.

‘

(Table 7, Appendix‘.

 

’'*"Significant at 1% level of probability.

)5

Table 5. Buzzwry of analyses of variance within 4 replications,
for 5 treatrents for each of j batch sizes.

 

Source of D.F. Kean Sguare
Variance 15 1o gal. 8 gal.

 

al.

0\
W:

m
9
P4
*4
in

m
SD
H
o

 

Total 11

Treatment 3 ljjl.4*‘ lle.7” 1205.§” 1502.1" 968.1"
Replication 5 54).} 377.2'* 117.6" 39.5‘ 513.7"
Error 5 56.“ 11.1 5.9 10.8 .2

 

Time and Temlerature. The end cooking temperature of the starch pastes

 

was arbitrarily set at 520 C for all batch sizes tested. The temperature

n

01 the case was recorded at two Linute intervals throughout the cooking
period for all batches. These temperatures were averaged for replica-
tions within each batch size and arranged as tine—temperature curves.
The average time-temperature relationship of each batch size during the
cooking process is illustrated in Figure 11.

These cooking curVes indicated that the 6 and E—gallon batch sizes
showed little difference in the time required for the mass to reach 620 C.
In these data the average beginning temperature for cooking in the C-gallon
batch size mas sliéhtly hifiher than the initial temperature average for
the f-gallon batch size. However, the end cooking temperature was reached

in the ease number of ainutes. If the beginnihg ccokinz temperatures had

w

been identical, it is possible that the average time required for the

 

IGianif‘icant at )3 level of probability
I"E“:i‘pfnif'icant at 11 level of probability

8 gollon

 

  

  
 

'0 gallon
{2.x
OII /' .Ooo-O. .
”I /@e 9.
o .-
/ \
- .3 l4 gallon

 

 

,.' IZQollon
70" I . o.
[2/
O. 0'.
0°.
65" '
60“
X
X .' .
d x I .0
fl xi...
5554 Xx{§
4 . -
.1 x..’e
e]:
.1 .0
in
'P ’:
50—1 ((5
‘JH
4!
q
q
45"
lllJJllJlllJlllll
Minutes 4 8 l2 l6 20 24 28 32 36
Figure 11. Average time-temperature relationships of batch
0 indicates first

size during cooking process.
visible evidence of thickening.

Ul
\JI

E-gallon batch sizes to reach the end cooking point might have been
increased slightly. The curves of the 10, 12, and lQ—gallon aaounts
indicated an orderly progression of increased tine required to reach 520 C
for each increaent in batch size.

The average‘teuperature at which the first visible evidence of
thickening of the mass, subjectively determined, had been noted was 790 C
for the 6, e, 13, and lQ-gallon batch sizes, and 7&0 c for the lO-gallon
batch size. Since this decision was purely a subjective one, this temper-
ature discrepancy was deened negligible. The temperature of initial
viscosity rise for all batch sizes tested was considered to be 79° C.

The time-teaperature relationship of the cooking curves showed that
increase in batch size increased the time required to reach the point of
initial viscosity rise as well as the time required for the temperature
of the mass to rise from 79° C to the and cooking teLperature of 82° C.
Preliminary tests had shown that cooled samples made with the same for-
mula cooked to higher temperatures had rel structure with an undesirable

degree of rigidity.

Treatnent. The analysis of variance of flow, Table 1, indicated that
there were highly significant differences attributable to treatment.
Further conparison indicated that the difference in flow between Series A
and Series B was greater than the difference between beries B and Series C
for all batch sizes teete . This observe ion suggested that the degree

of change in consistency was not directly proportional to time. Figure 12
shows the effect of holding time on the average flow of samples from the

five batch sizes tested.

0 minutes

CI: 30 minuies
-

60 minuies

Area Meosuremenl

square on.

  

 

   

 
 

_____________.l.|||.__._.I.H...........
======IH~”Human”
__________ IHHHHHH

   

i“

 

IOO -

95“

90"

85%

so-l

75“

a
0
7

IA

4‘ — W _ a q
5 5 O 5 O 5 O
4 2 2 l l

35‘
30-1

1
0
4

65“
60“
55‘
50“

l2 gal. l0 gol. 8 gel. 6 gal.

l4 gol.

site

Bolch

Effect of holding time on the average flow of

batch sizes of chocolate “is filling.

Figure 12.

.4

I"

The ”skin" foraaticn on the L658 during he hclding periods in the
kettle appeared conjarable for all batch sizes. It did not seem desirable
to include it in the final product. The renovai and discarding of this
"skin" constituted approxiaate-y three quarts of the mass for all batch
sizes and had an increased effect on the percentage loss of the finished
voluue as the batch size decreased. It seems feasible that holding the
mass in a covered, steam—jacketed kettle night appreciably decrease the
thickness of the ”skin” and the percentage loss of the finished volume.

Flow readings for all samples of four replications in each batch
size were averaged for Series A, Series B, and Series C. These fl w read-

ihs averages are listed in Table 4.

C‘.

Table 4. Junnary of average flow readinrs of four replications
of each batch size for each treatment.

 

 

 

Batch dize Series A series E Series C
6 gallon 62.7 4o.6 32.0
E gallon o#.j 55.) 2).;
1J gallon 55.4 43.1 §&.4
l2 gallon 7l.t #7.} 58.5
14 gallon 95.6 SC.) )j.u

 

A comparison of the average flow neasureaents of the cooled samples
on the basis of batch size indicated that the amount of flow was appreciably
greater for each treatment in the lh-gallon batch size than in the 5, 8, lo,
and 12—gallon batch sizes. It agpeared that the lb-gallon batch would re-

quire a longer holding period in the steam-jacketed kettle than would the

6, E, lu, and lB—gallon batches to groduce costarabie consistency.

Consideration was given to the variance of flow attributable to
batch size within each treatment. These analyses were based upon the
average flow value of the three poured samples for each of four replica—
tions of the five batch sizes tested.

The analysis of variance of flow readings for Series A, Table 5,
showed no significant difference attributable to batch size for 0 minutes
of holding time.

The analysis of variance of flow readings for Series B, Table 5,
indicated sirnificant difference attributable to batch size for $0 minutes

of holding tine. In a coacarison of the mean flow value for each batch
size, no significant difference was established between the 6, E, 10, and
lZ-gallon batch sizes. However, significant difference was apparent
between the mean flow value of the l4—gallon batch size and that of the
other four batch sizes studied.

Table 5. Analyses of variance for treatment with 4 replications
and j batch sizes.

 

 

 

 

 

Source of Series A Series B ‘_ series 0
Variance D.F. N.3. F. D.F. M.S.‘ F. D.F. h.5. F.
Total 171 181 171

Replication 5 154.6 .9 5 62.2 .6 5 41.6 .5
Batch Size 4 620.8 5.; 4 §7u.l ).4‘ A 398.7 4.6.
Error 10 208.) 11 105.6 10 87.6

 

 

*Significant difference at the 3% level of probability

lAdjusted for sanple averages affected by Lissing values in
E-gallon batch size.

The variance of flow readings for Series C indicated sign'ficant
difference in flow attributable to batch size for 60 minutes of holding
itime. This analysis of variance is indicated in Table 5. In the com-
parison of the mean flow value for each batch size of Series C the trend
of significant difference was similar to that of Series 8. Significant
difference in flow was found between the lA—gallon batch size and the
other batch sizes tested. There was no significant difference between
the mean flow values for the 6, E, 10, and lE—gallcn amounts.

According to subjective observations of cut samples of cooled
filling for Series A in all batch sizes, products obtained by this treat-
nent were considered too fluid for serving. Sasples for Series B were
judged acceptable for use as pudding, but the consistency was too soft
for pie fillirg of satisfactory consistency. The samples of Series C
for the 6, 8, 10, and lD-gallon batch sizes showed dependable stability
and gel strength judged necessary for pie filling. Samples of this
series frox the lQ—gallon batches were fairly dependable for use as a
pie filling but were softer than those from the other batch sizes. The
subjective standard used to deternine suitability of the cooled aixture
for pie filling was designated as a filling whi i, after cutting, had
sufficient structure to allow a slight degree of bulge but which did not

continue to flow during subsequent standing.

(.‘\

31.17. ARY

The effect of batch size upon flow was studied by using a basic
foraula in which the proyortion of ingredients was held constant. The
end cooking temperature was arbitrarily set at 82° C, and holding periods
after this teaperature was reached were 0, 50, and 5d ainutes.

Significant differences, attributable to replication within a
batch size, were found in the 6, c, l”, and lZ—gallon aLoun e. No sir-
nificant difference, resulting from replication, was found in the l4—sallon
anount. This resuLt may have been attributable to the known error in
grcparation technique for eons of the samples in the first rerlicatiOn of
the lb—gallon aaount.

Tine-tenterature cooking curves showed no difference between the

I 1 - ' ' . . 3 O O -
6 and C-Tallon amounts in tine recuired for tne Lass to reacn (2 C. The
54 L

data indicated that the average beginning cooking teaperature of the

(1“

E-gallcn atch size was higher than that of the f—gallon amount. It is
possible that this fact gave a scnewhat distorted effect to the average
cooking curve for the E—gallon amount. Average cooking curves indicated
that consecutive incre sea in batch size showed correstonding consecutive
increases in the tins reiuired for the :ass to reach 790 C, the joint of
visible, initial viscosity, and the additional time required to reach the
end cooking temperature of 520 C.

Variance resulting from treatxent was found to be significant for
all batch sizes. Differences in sverag flow Leasureaents were greater
between Series A and Series 8 than between Series B and Series C. This
result indicated that the degree of hangs in consistency was not directly

proportionate to the length of holding time. The degree of flow for each

a . ' * I " ""- c‘ ’- :IL‘" 1* "\‘ ‘ . “‘l “ “‘ 1‘ “ “"
bLClelC lc-;1nr gerio: Via a ,reclao.; Lreater in one lw-tallon batcnee

than it was in ccrreogonuing holding beriojs for the 5, t, lo, and
lE-gallon bitches.

Analysis of the scan flow readings for all bitch sizes w'thin each
specific treatLent showed no significant difference attridutable to batch

size for Series A. Average flow values analyzed for Series B and Series C

l

indicated no sifniflcant difference in flow Value within each series attri-

FJ.

butable to batch sine for the C, 6, 1J, and lB-gallon anounts. Sifnif cant

difference use ajgarent betwee. the M€fifl flow value for the lA—gallon

C"

amount and all other ate: Lith both for the 36—uinute and for the

5o—ninute holding periods.
The subjective standard ULCd to deteruine suitability of the cooled
nixture for yie filling was deeirnatei as a filling which, after cutting,

had sufficient structure to allow a slijht degree of bulge but which did

not continue to flow during subsequent standing. Bubjective observations

U)

Ser es A were too fluid for serving. All

*1.

indicated that all the angles of
samples of Series B were judged to be acceptable for use as pudding but
too soft for use as pie filling. In Series C the sanyles fron the o, 5,

lo, and lZ-gallon batches were rated as being entirely dependable for

es C from the lh-gallon batches proved

H.

use as pie filling. Savples in 3er
suitable for use as tie fillin: but were softer than those from the other

batch sizes.

l v

(V) .

COIICLL’J 10253

From this investigation it appears that flow characteristics of
cooled, cut caLples of starch-thickened pastes are not consistently
affected b' increases in batch size when procedure and proportion of in—
gredients retain constant. Within the liaits of this study the 6, 6, lo,
and ll-gallon batches produced gel structures of sihilar consistency.
Althourh the 14~gallon amount produced a less stable gel structure than
did any of the other batch sizes tested, factors other than batch size may
also have influenced the flow of sarples.

A progressively longer cooking period is required to reach the
points of visible, initial viscosity and end cooking teLperature for each
consecutive increase in batch size. From the data of his investigation
it appeared that the degree of swell of the starch granules is dependent
Upon batch size, rate of heating, and tenperature of the ness during the
heating and holding periods.

The length f time that the mass is held in the steaL-jacketed
kettle, after tLe temperature of 620 C is attained, appears to affect the
stability of the gel structure in all batch sizes. Riqiiity of gel struc-
ture increased more during the first 50 .'nute3 of holding tine than
during the following $0 Linutes f holding tine. As the length of the
holding period increased from O to 60 minutes, visible increases in hot
paste viscosity of the mass were noted. This fact indicated that the
starch granules continue to swell after the application of steam is dis-
continued. In all cases, the temperatures of the mass renained between
79° C and 82° C for the 6o minute holding period. These findings suggest
that the rate of heating and the length of the holding period are contributing

factors in the final fl w of the cooled paste.

\

Corparitcn of f-ow cnaracteriatics within each s;ecific baton sine
indicated tLat the sa plea from the ls—gellon amount did not have the sane
consistency as sanp-es froa other batch sizes when all were held for the
sane length of tire under the ease coniitions. The effect of batch size
upon flow for anounts greater in n 14 gallons is not predictable from
this study.

The :elc resulting fron the fio-ninute hailing period were judged

catples f'rOu. the

('1
P
[x
Q
(r,
f“
m
(I
(+
(h
to

suitable for use as guiiing for all batch
OO—ninute holding pcrici rave gels acceptable for use as pie filliny.
In all cases gel structure of samples heli ou minutes was tender but

'ossibility of regulating stability and

g
A

stable. These facts suggest the
tenderness of cooled starch-thickened nixtures, for specific batch sizes,

by control of tine and temperature coniiticns of the cooking period. It

9

seems feasible that the same fortula can be usei for the troduction of

pudding and pie filling with the control of the final eel structure being

\.

dependent upon tne heatihfi and coolins conditions of the mass rather than

upon varying concentrations of starch.

Recipes for starcn-tnichened puddincs and pie fillinrs fenerally

\—

contain two or Lore ingredients which contribute to the total tnicxening
effect in the finished product. The results of tkis study, therefore, are
only applicable to formula: in which the thickening agents are liLitei to
.cornstarch and cocoa powder vhich, when they are conbined in equal con-

/

centrations, constitute 7.o per cent of

J

the total weight of the mixture.
The finiings of this stuiy enthusize t.at accurate prediction of
the stability of gel structure of starch—thickened pastes is a complex

problem. Additional investiretion of the interaction of factors, such as

k‘)\
#7

rate of heating, tenperature of the mass during the heating period, end
cooking tenperature, ani length of ho‘lihg period after the application
of steam is iiscontinuei, which contribute to the stability of a cooled

starch paste needs to be made before the effect of batch sise upon flow

can be accurately deterninei.

LITERATURE CITED

Alsberg, C. L. Studies upon starch. Ind. Eng. Chem. 15: 190-195.
1935.

Alsberg, C. L. and Rask, O. 3. On the gelatinization by heat of
wheat and maize starch. Cereal Chem. 1: lu7—116. 1924.

Anker, C. A. and Geddes, W. F. Gelatinization studies upon wheat
and other starches with the amylograph. Cereal Chen. 21:

555-560. lgah.

Eaten, W. D. Formulas for finding estinates for two and three
missing plots in randomized block layouts. Mich. State College
Agr. Expt. Sta. Tech. Bull. 16}. 1959.

Bechtel, W. G. heasurenent of properties of cornstarch gels. J. of
Colloii Sci. 5: 250—270. 1930.

Bechtel, W. 3. A stuiy of some taste characteristics of starches
with the Corn Industries viscoaeter. Cereal Chem. 24: 200-214.

1947.

Bechtel, W. G. and Fischer, E. K. The neasurecent of starch paste
viscosity. J. Colloid Sci. 4: 255-282. 1349.

Billings, M., Briant, A. h., Longree, K. and Harris, K. W. Cream pie
fillings prepared in nultiples of an eight-pie batch. J. of An.
Diet. Assoc. 28: 22C—35Q. 1952.

Bisno, L. Thickenings used in pieofillings. Bakers Digest. 2) (no. 1):
26-29. 19jl.

Brinhall, B. and Hixon, R. L. Interpretation of viscosity Leasureaents
on starch pastes. Cereal Chem. 19: ABE-#40. lyh2.

Briahall, B. and hixon, R. h. The rigidity of starch pastes. Ind.
Eng. Chem. (anal. ed.) ll: 558-561. 1959.

Caesar, G. V. Consistency changes in starch pastes. Ind. Eng. Chem.
24: lAjB-lfifi}. 1952.

Caesar, G. V., Huron Killing Co. Harbor Beach, rich. Information on
viscosity neasureaent of starch paste. (irivate conrunicstion).
1953.

Caesar, G. V., and Foore, E. E. Consistency changes in starch pastes.

Ind. Eng. Chen. 27: lhk7—1451. 195).

Canpbell, H. A., Hollis, E. Jr., and hcAllister, H. V. sproved uethods
of evaluating starch for specific uses. Food Tech. A: 492-495.

1950.

16.

17.

16.

19.

[0
(j

22.

27.

Cox, R. E. and Higby, R. H. A better way to determine the jelling
power of pectins. Food Ind. 16: 441-442; ij—qu. 1944.

Ferree, h. J. The effect of the protortion of sucrose on the vis-
cosity of cornstarch pastes made with different liquid mediums.
Unpub. h. S. Thesis. East Lansing, hichigan, Lichigan State
College Library. 19j3.

Frankel, J. A. A practical treatise on the manufacture of starch,
glucose, starch-sugar, and dextrine. p. 1—50. Philadelphia.
Henry Cary Baird Co. 1681.

French, D. Physical properties of starch. In herr, R. W. Editor.
Chemistry and industry of starch. 2nd Ed. New York. Acadecic
Press Inc. 195d.

Graweaeyer, E. A. and Pfund, h. C. Line-spread as an objective
test for consistency. Food Res. 8: lcj-lofi. 1945.

Hains, A. J. The effect of sucrose, citric acid, and tenperature
on viscosity and gel strength of cornstarch pastes. Unpub. h. S.
Thesis. East Lansing, Fichigan, lichigan State College Library.

1955.

Hanson, H. L., Caapbell, A., and Lineweaver, H. Preparation of
stable frozen sauces and gravies. Food Tech. 5: 452-435.
1951.

Hanson, H. L., Fishita, K. D., and Lineweaver, H. Preparation of
stable frozen puddings. Food Tech. 7: 462—455. 1955.

Harris, R. H. and Banasik, O. A further inquiry regarding effect
of electrolytes on the swelling of cereal starches. Food Res.

15: 70—51. 1948.

Harris, R. H. and Jesperson, E. Factors affecting some physio—
cheaical properties of starch. Food Res. 11: 216-228. 1946.

Harris, R. H. and Jesperson, E. A study of the effect of various
.factors on the swelling of certain cereal starches. J. of Colloid

Sci. 1: 479-495. 1946.

Jordan, R., Wegner, E. 8., and Hollander, H. A. The effect of
homogenized silk upon the viscosity of cornstarch pudding.
Food Res. 18: 549-538. 1955.

Kerr, R. R., Editor. Chemistry and industry of starch. 2nd Ed.
New York. Academic Press Inc. 1950.

Kesler, C. C. and Bechtel, W. G. Recording viscometer for starches.
Anal. Chem. 19 (no. 1): 16-21. 1947.

\fi
F4

67

lnowles, D. and harris, R. H. Cbservations on the behavior of starch
gel from different classes and varieties of wheat. Food Res. 5:

Longree, K. Viscosity of white sauces prepared in quantity. J. of
Am. Diet. Assoc. 29 (no. 1o): 997—1us5. 1955.

Lowe, B. Experimental cookery. 5rd ed. Kew York. John Wiley and
Sons, Inc. 1. Aug—41o. 1944.

. ~ a . Relative viscosities of wheat
Ind. Eng. Chen. 25: 45C-4bo. 1955.

iansels, C. E
starches.

horse, L. h., Davis, D. 3., and Jack, E. 1. Use and properties of
nonfat dry milk solids in food preparation. Part 1. Food Res.
15: 2oU—215. 1950.

Nutting, 3. C. The effect of electrolytes on the viscosity of potato
starch pastes. J. of Colloid Sci. 7: 128—159. 1952.

Catwald, W. I ;ortance of viscosity for the study of the colloidal
state. Farriday Soc. 9: 54. 1915.

iley, J. A. Starch and its derivatives. Few York. 3. Van Nostrand

Co. Inc. 1/4o.

Sanec, l. The colloid-cheuical yroperties of starch in relation to
chenical constitution. In Walton, R. P. Editor. A coaprehensive
survey of starch cneristry. Vol. 1. New York. Chenical Catalogue
Co. Inc. p. 51-54. 1936.

Schoch, T. J. A decade of starch research. Bakers Digest. 21 (no. 1):

Physical aspects of starch behavior. Cereal CheL. 1E:

Sjcstrou, C. A. licroscopy of starches and their uodifications. Ind.
Eng. Chen. 2E: 35-74. 1956.

Tanner, L. h. an. Englis, D. T. A study of starch fron different
varieties and types of corn. Food Res. 5: 565-5C1. 194C.

Taylor, T. C. Hon-carbohydrate constituents as a factor in the char—
acterization of starch contonents. In Walton, R. I. Editor. A
ccnprehensive survey of starch chenistry. Vol. 1. p. 62-35. Sew
York. Chemical Catalogue Co. Inc. 1925.

Trexpel, L

The use of starch in tie fillings. Bakers Digest.
30 (no. u): 3

3-3-5, 28. 1C460

Whistler, R. L. and Snart, C. L. Polysaccharide Chemistry. New York.
Acadegic Press Inc. p. 239-275. 1955.

_ J

O .
C

R L. and fieatherwax, l. A ylose content of Indian corn—
tral, and quth A erican corn . Cereal

ML

46. Whistler, .
starches froh horth, Cen

Cher. 35: 71—7). 1948.

47. Voodruff, S. and hachasters, h. h. Gelatinisation and retrograda—
tion chances in corn and wheat starches shown by phctoxicrographs.
Ill. Agr. EXp . Sta. Bull. 445. 1956.

48. Hoodruff, S. and Jicoli, L. Starch gels. Cereal shes. 1: ; f

APPENDIX

Table c. Measureuent of flow: original data. P.3niuctcr rcaiinya in

square centiLeters.

 

BATCH 31 REPLICATICN SERIES A: 0 MINUTE

L~
F7:

.5 Alv’J'LE AU} BER?)
1 2 5 Mean

 

y.)

O‘KJNJKJ

fi'r

13 gallon

‘erxl
£“U ka

JI‘W {u H
\’ (‘3
F
iu\.N (_
\J
\J
‘.

 

bean /7.Q Jt-T 73.1 9 .3
12 yallqg l 5’ 8 61.4 5A.L 61.9
3 7/0} })'; >404 1150A
5 é?.d 5.) {).. 73.5
A )0.) 3;.) 71.} )L.l
Ream 74.5 7Q.) 7v.) 7;.8
,- , 7 4 3-. 72 ) 7) ~
_L‘ rulrgg 1 ,h°: /--: igo~ [-oj
3 GE.) 97.C (1.2 32.5
5 j).5 )5.4 )5.7 37.1
a 7a.5 79.4 $2.. 74.2
1‘.Pan Ego? {/60} 170‘) gbo|
f fa.lqg 1 5J.. Q4.£1 32,. 62,4
2 51.43 01.7* 55.? 52.4
- A ) _ ) --
5 27.4“ 27.4‘ 9 4* 9;.4
4 71.2 r u 7w; 7;.6;
Mean 52.5 i).l :j.€ 54.5
g :allon 1 73.7 53-7 75-1 73-3
3 04.5 £5.u 33.1 63.1
5 Ql.v JV u 5C.E 59.3
4 )5.u 4c.€ 43.1 49.}
Mean C&.§ L).Q Lv.5 62.7

 

*Nissing value for lost sanpie.
:Eodificd value.
’sanple not leveled.

 

 

Table {continued}
51.141213 8: 50 1.11me 323113.: 0: 6:2 1.1.2.123
51.1-11.2 :.U1»31:Rs 5.41.1211: 1.11.2235

l 2 5 Mean 1 2 5 Lean
55.5 5 68.6 57.7 78.4 59.8 ‘5 5 51.5 57.2
74.2 75.4 72.4 75.5 57 o 52.7 52.7 61.4
)4.8 65.1 61.] 39.7 145.} 116.6 14.2 43.6
o..7 55.- 6; 2 52.; 54.2 56.; 55.4 55.5
72.1 17.7 55.5 as 5 55.2 54.4 55.. 55.9
42.. 4-.7 41.; 41.6 55.6 26.2 5e.4 51.4
55.5 55.5 26.1 52.1 25.5 22.2 24.2 25.2
55.5 52.; 5;.8 47.9 47.0 44.5 57.7 45.2
67.. --.5 53.45 55.2 .57.5 55.2 51.2 54.2
45.1 45 c 5 .5 47 5 42.5 57.5 55.c 58.6
47.5 54.5 51.7 51.1 55.5 55.8 55.. 55.2
42.; 45.2 44.2 45.8 57.5 25.4 28.9 51.0
59.5 55.4 54.5 57.8 51.0 23.4 25.7 27.7
45.5 52.6 45.4 47.6 1.7 42.5 4u.o 41.4
45.5 +7 4 4+ u 45 1 57.5 55-5 52.4 54.4
42.2 55.4 57.5 52.4 55. 25.4 24.5 25.4
41.5 55.3 55.5 55.9 58.. 24.5 52.1 51.5
2, 1 2 I 2 fi’) ’ -’ .’ v 1' '-
jQ.2 54.2 34.2 55.3 2C.(~ 2; (* 2e.7~ 2; I
46 g 45.9 54.5 41.5 52.5 55.41 27.; 55.2
49.) 52.1 5c.4 58.5 55.2 28.5 27.5 29.9
49,5 55.2 45.6 50 6 45.1 4v.2 42.6 44.0
45.9 43.1 46.5 45 5 56.5 54.5 29.6 55.5
41.4 58.2 58.7 59.4 54.4 27.5 52.2 52.7
28.5 25.5 24.7 27.9 25.4 19.: 18.9 22.5
42.2 59 J 40.9 42.9 57.1 30.5 5..4 52.6

 

*Rissing value for lost eaxple.
glodified value.
Bangle not leveled.

1e 7.

fiummary of range and REun flow measurcuents for each

batch size. ’
\

eguare centimeters,

 

 

 

 

 

 

 

Batch Size Treatnent: Holiing Time
Gallons
J *in. jJ "in. 5, 'in.
Range Mean Ran t Lt m 32.56 Kean
14 137.5 - 77.0 £5.6 98.8 - 34.1 36.} 57.5 — 45.1 53.0
12 91.} — 54.4 71.6 {5.4 - 33.1 47.) 57.5 — 13.2 58.;
12 76.4 _ 55.7 66.4 54.5 - 54.6 45.: 42.5 - 25.7 54.4
& 7E.y — 57.4 L4.3 4:.8 - 54.3 58.) 55.4 — 25.4 2;.)
6 82.7 - '16. 62.7 55.2 .. 2...: L4,; .. -89, 52.6
.
Table 5. Par ce5t flow ieviatica Frcm HEAR of uuuplte within
C3CJ batch size.
Batch 3129 TreatLent: Holjing Tine
Gallons
0 sin. ‘23 min. ._.,__«.- aQfiuip.wv,.
+3 -3 +3 —T +3 -3
14 55.0 17.7 41.3 3;.e 33.3 21.6
12 , 27.4 24.2 81.9 46.8 45.4 43.)
1. 11.7 21.} 20.4 35.5 25.} 3).}
E 23.5 11.6 19.} 11.2 51.8 ' 3;.7
5 51.9 7C.) ju.l 54.} iu.6 42.0

 

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