SOME PHYSICAL PROPERTIES OF MILK
FROTEIRS AM} SOYBEAN PRGTEEN ISOLATES

IN A SIKULATED MILK SYSTEM

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MECHIGAR STATE UNIVERSITY
Elizabeth A. Hoffman

1974

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ABSTRACT

SOME PHYSICAL PROPERTIES OF MILK PROTEINS AND SOYBEAN PROTEIN
ISOLATES IN A SIMULATED MILK SYSTEM
by
Elizabeth A. Hoffman

A study of the interactions of various milk proteins
and soybean protein isolates was undertaken to see if such mix-
tures were compatible in a fluid system. Sols of 2.5% casein
and 0.8% whey protein concentrate were replaced with increas-
ing increments of soybean protein isolates. After their pre-
paration the sols were either evaluated or heat treated for
145°F/30 minutes, 165°F/flash, or 175°F/ 15 minutes, cooled
and subsequently evaluated. Sensory evaluation included
subjective observation of color and odor. Viscosity was
measured with a Brookfield viscometer. The concentration
of soluble protein was determined by Lowry protein assay.
Whipping ability was measured by the volume of foam produced
and foam stability by the amount of liquid collected from
the foam. The amount of oil emulsified signified the emul-
sification ability.

Sensory evaluation revealed a significant change in
color and flavor as casein sols were replaced with increasing
amounts of soybean protein isolate. The color remained un-

changed but flavor and odor changed markedly with increasing

Elizabeth A. Hoffman

concentration of the soy protein in the casein—soy replace—
ments, but increased slightly with the whey—soy sols. Whip—
‘ ping ability appeared to be little affected by replacing milk
proteins with soy protein. Foam stability decreased greatly
as casein was substituted by-soy protein but improved as soy
protein replaced whey proteins. Emulsification ability de-
creased for both the casein—soy and whey—soy replacements.
There was no indication in any of the evaluations that any
interactions of casein, whey protein concentrate, and soy-

bean isolate had occured.

SOME PHYSICAL PROPERTIES OF MILK PROTEINS AND SOYBEAN PROTEIN
ISOLATES IN A SIMULATED MILK SYSTEM
by
Elizabeth A. Hoffman

A THESIS
Submitted top
Michigan State University
in partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE

Department of Food Science and Human Nutrition

197A

T0 JIM

ii

ACKNOWLEDGEMENTS

My sincere thanks are extended to Dr. C. M. Stine for
his counsel and guidance throughout this study and in pre-
paration of this manuscript.

Appreciation is also extended to Dr. J. R. Brunner and
Dr. H. A. Lillevik who reviewed this manuscript.

The author is also grateful to Clem Kuehler for his
valuable assistance without which this study could not have
been undertaken.

Appreciation is also extended to the National Institutes
of Health for their PHS Traineeship Grant number 5 A10 00639

which provided my financial support during this study.

iii

TABLE OF CONTENTS

INTRODUCTION
REVIEW OF LITERATURE

World Usage of Soybean Protein

The Properties of Soybean Isolates
The Proteins of Milk

The Properties of Casein

The Properties of Whey Proteins

EXPERIMENTAL PROCEDURES-

Exploratory Tests
The Model System
Sensory Evaluation
Viscosity

Soluble Protein
Whipping Properties
Emulsification

RESULTS AND DISCUSSION

Exploratory Tests
Sensory Evaluation
Viscosity

Soluble Protein
Whipping Properties
Emulsification

SUMMARY AND CONCLUSION
LITERATURE CITED

iv

Table

LIST OF TABLES

Preliminary tests for solubility of soyprotein
isolates and casein in distilled water and
Koops' buffer.

An analysis of variance for individual data
points.

The whipping stability of Promine-F and Promine-D
replacements of Wpc in Koops' buffer.

Page

19

25

35

Figure
1. The
2. The
3. The
4. The
5. The
6. The
7. The
8. The
9. The
10. The

LIST OF FIGURES

viscosity of Promine-F and Promine-D replace-
ments of casein in Koops' buffer.

viscosity of Promine-F and Promine-D replace-
ments of Wpc in Koops' buffer.

soluble protein of Promine-F and Promine—D re-
placements of casein in Koops' buffer.

soluble protein of Promine-F and Promine-D re-
placements~of Wpc in'Koops!vbuffer:ra-"

whipping ability of Promine—F and Promine-D
replacements of casein in Koops' buffer;

whipping ability of Promine-F and Promine-D
replacements of Wpc in Koops' buffer.

whipping stability of Promine-F and Promine-D
replacements of casein in Koops' buffer.

emulsification ongromineeF,and Promine-Dzre—.
placements of casein in Koops' buffer.

emulsification of Promine-F and Promine-D re-
placements of Wpc in Koops' buffer.

emulsification of Promine-F replacements of

casein and Wpc with coconut oil with no heat
treatment.

vi

Page

23

2h

27

29

32

33

3A

38

39

#0

INTRODUCTION

The need to increase world protein supply has been
widely accepted and studied. According to Altschul (1966),
about fifty percent of the world's children receive adequate
protein nutrition. In 1970, there was an estimated world
protein deficit of twelve percent. Even if the amount of
protein is increased, this will not necessarily solve the
problem, since it is the "amino acid profile"~of the protein
which determines its nutritional value. Futhermore, it is
necessary to maintain production with world population
growth, which is increasing by seventy million each year,
(Kosikowski, 1969).~ Also, those areas with the peak pOpu-
lation growth are currently both overcrowded and underfed.
The staple foods in Asia and Latin America are grain, beans,
fish and rice. In the Near East and Africa there is some
milk consumption, but still an insufficient amount for good
nutrition. This obvious need for increased protein supply
has stimulated definite interest in the development of
vegetable protein foods. While a typical acre of land may
produce forty-three pounds of animal protein, it could
produce four hundred fifty pounds of soybean protein. Such
production would also increase caloric output four times.’
Increased consumer acceptability, desirable sensory qualities
and dietary reduction of cholesterol and fat are desirable

1

2
attributes of vegetable protein use (Childers, 1972).

A way of extending animal protein has been devised
(Chandrasekhara, 1968; Chandrasekhara et al., 1971).. This
process, developed at the Central Food Technological Research
Institute, produces Miltone, which is buffalo milk "toned"
(extended), through the use of peanut isolate. The object
was to make rich buffalo milk available to the vast popu-
lation of India. Miltone, which can be stored up to six
months at room temperature, and has the accepted color,
flavor, mouthfeel, and nutritional‘value of milk, has been
widely accepted in India. In 1971 (Anonymous), it received
the Food Technology Industrial Achievement Award from the
Institute of Food Technologists. In 1973 (Anonymous), Miltone
was being produced in two cities in India, with two more
plants being planned. Considering the wide growth of soy-
bean production of the United States, as described by Ioanes
(1973). it would be feasible to consider a similar process
using soybean protein isolate. For that reason the project
of studying the interactions of various milk proteins and
soybean isolates was undertaken to see if such mixtures

were compatable in a fluid system.

REVIEW OF LITERATURE

World Usage of Soybean_Protein

The composition and general prOperties of soybeans
have been described by many authors (Williams. 1971; Wolf,
1972; Holland, 1968). The most important consideration
is that soybeans are approximately forty percent protein.
This protein is made available through a variety of forms:
whole beans, full fat flours, defatted flakes and flours,
soy protein concentrates and soy protein isolates. Each
form has an increasing amount of protein. All of these
forms contain the essential amino acids necessary for growth,
except for a deficiency of methionine, which may be added as
a supplement (Anonymous, 1972; Badenhop and Hackler, 1973).
Whole soybeans, in various forms, have been used in the Orient
for many centuries, but the taste and odor, often described
as painty, beany, or bitter (Nelson et al., 1971), is often
objectionable to Western taste. However, the destruction
of the enzyme lipoxidase by the heat generated in grinding
(Holland, 1968), or blanching (Nelson et al., 1971), during
the extraction process eliminates most of this problem.

One of the earliest attempts to increase world protein
intake was through the development of what is known as CSM,

a mixture of corn, soya protein and milk, which produces a

3

L,
nutritionally balanced food (Inglett et al., 1968). This'
product was found to be stable up to one hundred degrees
Fahrenheit for one hundred eighty days, and by adding water.
could produce a dough for an unleavened bread. So far, it
has been distributed in ninety countries, and has been well
accepted in all. According to Bockwalter et al. (1971), one
hundred grams of CSM must contain three hundred fifty kilo-
calories, eighteen to twenty-two grams of protein, two grams
of fat and one gram of linoleic acid. Studies are now being
carried out to determine which formula provides maximum
nutrition at a minimum cost.

Mustakas et a1. (1971) have developed another way of
making soy protein available. First produced at the Northern
Agricultural Research Service (Anonymous, 1970), their protein
concentrate, as it is called, makes available a product
similar to milk at a lower cost. It is produced by adding
soybean oil, emulsifier, sucrose, salt, flavoring, vitamins,
and minerals to a full fat soy flour. It is made available
in a form which can be reconstituted in water. The product
has a good shelflife, acceptable flavor, and nutritional
quality similar to cow's milk. At the time, the cost was
estimated to be only ten cents per gallon, which would make
it extremely competitive with other foods for feeding people
in developing nations. Kosikowski (1969) believes that this
type of beverage is nutritionally superior to any kind of
imitation milk, especially when a native protein base is

used. However, the acceptance of a new food by the uneducated

5

and the role of their governments in allowing new, com-
petitive industries to develop are limiting factors in the
processing and distribution of a protein beverage concen—
trate.

Synthetic milk includes both filled and imitation
milks. The distinction between the two has been described
by many (Holland, 1969; Brink et al., 1969; Council of Foods
and Nutrition, 1969; Moses, 1969; and Anonymous, 1969). As
defined by Congress, filled milk is a milk product to which
a fat or oil has been added to form an imitation milk. On
the other hand, there is no regulation for imitation milk,
other than a regulation prohibiting the use of any milk
products.

Soybean milk, the main type of imitation milk, has
been used in the Orient for centuries, (Standal and Kian,
1969), but it was first introduced to this country to be
used by infants who were hyperallergic to cow's milk
(Anonymous, 1963). Shih (1970) also prescribes soybean milk
for cystinosis, homocystinuria, and lowering tendency for
athersclerosis. The most widely accepted consideration
for most American consumers, for both imitation and filled
milks, is its lower cost. Standal and Kian (1969) feel the
lower cost of imitation milk could make it available in
developing countries to assist in the prevention of mild
and even severe kwashiorkor. In such countries, cow's milk
is often expensive, diluted, and may be unhygenic. As first

described by Collins-Willims (1956), Powdered Sobee, a soy

6
based infant formula, contains 3.4% protein, 2.7% fat, 8.1%
carbohydrate, 0.2% fiber, 0.5% ash, and 85.1% moisture.
Forman et al.(1964), Holt (1965), Howard et al. (1956), Kay
et a1. (1960), and Tiling et a1. (1961), all believe that
such infant formulae are nutritionally adequate for infants.
However, Theurer and Sarett (1970) caution that when soy
isolate is used instead of soy flour, it is necessary to add
those nutrients absent from the isolate. When soy isolate
formulae are supplemented with methionine, they have ninety
percent or more of the efficiency of casein.

With the success of these infant formulae came the
development of imitatiOn and filled milks for the consumer.
Holland (1968; 1969),USDA (1969), and Anonymous (1968), list
typical formulations of synthetic milks. Imitation milks
generally contain soybean isolate, sodium caseinate, corn
syrup solids, vegetable fat, stalilizer, water,vvitamins
and minerals. Filled milks may contain nonfat dry milk
solids, coconut fat, emulsifier, vitamins, and water. Noyes
(1969) gives the step-by-step processes of three companies
in their preparation of synthetic milks.

The major factor which prevents the synthetic milks
from being widely accepted is their taste. Shih (1970)
believes that soybean milk could be consumed just as easily
by American adults as well as infants, but that the taste
is the major deterrent. According to Holland (1968), imitation
milks do not taste like fresh milks, but they are palatable.

Chocolate, black cherry, and black and red raspberry flavors

7

all improve the sensory qualities of the product. Holland
(1969) states that sodium caseinate, not soy protein isolate,
should be used in an imitation milk to obtain milk flavor.
Other factors than taste affect consumer response to
these products (Jacobsen, 1969; Kosikowski, 1969). The
willingness to accept imitation products and their cost are
also important factors. Milk substitutes range from five to
twenty cents per half gallon less than homogenized whole milk
(Anonymous, 1968). However, Koskowski (1968), Brink (1969),
and Council on Foods and Nutrition (1969) state that these
products actually are more expensive than milk nutritionally,
because of insufficient protein being used for a good amino
acid profile. They have urged that the nutritional value
of these products be increased so that they can be used to
provide the needed nutrients to both American children and

those in less fortunate countries.
The Properties‘of Soybean Isolates

According to Central Soya Chemurgy Division (a and b),
soybean protein isolate is a vegetable protein derived from
the major storage globulins of the soybean. It is at least-
ninety-six percent protein on a moisture free basis, and con-
tains all the amino acids essential for human nutrition.
Johnson and Circle (1959) found it comparable in nutritional
value with casein on a weight basis. When supplemented with

methionine or used with methionine-rich foods, it has

8
outstanding nutritional value (Central Soya Chemurgy Divis-
ion, a and b). The product, which is obtained by solvent
extraction, acid precipitation, and spray drying, is recom-
mended by Central Soya Chemurgy Division (a and b) and
Johnson and Circle (1959) for a wide variety of uses,
particularly in bakery goods, cereal and dairy products,
meat type products, speciality foods, and synthetic milks.
Fujmaki et al. (1968) found that it is difficult to remove
characteristic soybean flavor, even from soybean isolate, and
this hinders its use in certain food products. Yasu-
matsu et al. (1972 a) found that raw soybean flavor is absent
from soybean isolate, but that it still contains a major
soybean flavor characteristic. Nonetheless, when this fla-
vor is masked, the isolate may contribute a variety of de-
sired characteristics to a product. According to Belshaw
(1971), these properties include thickening, emulsion form-
ing capabilities, film forming abilities and gelling capacity
and water binding properties similar to milk or egg proteins.
Yasumatsu et al. (1972 b) agreed that soybean protein
isolates have good whipping and emulsifying capabilities.
Williams (1972) stated that isolates have a pH—solubility
relationship similar to casein and may therefore be substi-
tuted for casein and caseinates in food products. Belshaw
(1971) found the isolate he studied to be ninety percent
scluble in aqueous solutions with moderate agitation, but
Wolf (1972) cautioned that commercial isolates vary ap-

preciably in solubility and therefore should be evaluated

9
individually. Chakraborty and Hansen (1969) did find that
several caseins stabilized the solubility of soy isolates
in milk salt systems. Sugimoto and Van Buren (1971) attribu-
ted stabilizing effects in soy solutions to monosaccharides,
.disaccharides and corn syrups. At concentrations above
seven percent, viscosity will increase and gelation will
occur upon heating (Wolf, 1972; Williams, 1972).

Finally, cost will determine the availability of the
isolate for use in milk extension. Belshaw (1971) found
that soy isolate made protein available at half the cost of
skim milk, and one quarter that of whole egg solids. Ul-
timately, it will be the cost and availability of soybeans
on the world markets that will affect its being used as a

milk toning agent.
The‘Proteins of Milk

Although milk does not contain an especially high
amount of any one particular nutrient, it is a uniquely
balanced source of man's dietary requirements of protein,
fat, carbohydrates, vitamins, and minerals (Jenness and
Patton, 1959; Hartman and Dryden, 1965; Lampert, 1970; and
Kon, 1972). Also, it contains a significant amount of pro-
tein, which is the most essential nutrient which cannot be
produced synthetically (Kon, 1972). More importantly, milk
contains the daily requirements of almost all the essential

amino acids (Lampert, 1970). Milk proteins themselves are

10
classified as caseins, which precipitate out of milk at a
pH of 4.6, or whey proteins, which remain in solution at a
pH of h.6._ Thompson et al. (1965) gave a thorough review
of the many forms of both caseins and whey proteins. In a
more recent review, Lyster (1972) reviewed the nomenclature,
amino acid sequences, and primary, secondary, and tertiary

structures of caseins and whey proteins.
The Properties of Casein

Caseins exist in large colloidal particles containing
the protein and considerable quantities of calciumzand
phosphate, and some magnesium and citrate (Jenness and Patton,
1959). Many models have been offered as to how these are
arranged in the casein micelle (ROse, 1969). These micelles
can be removed from milk by several processes (Jenness and
Patton, 1959; Gordon and Whittier, 1965). High speed
centrifugation will remove casein and leave whey proteins
and other dissolved constituents in solution. Isoelectric
precipotation can be achieved by lowering the pH of milk to
#.6. Casein may also be coagulated and removed from the
whey by rennet, as is done in the cheese making process.
Casein will also precipitate from milk saturated with sodium
chloride.

The physical and chemical properties of casein have
been studied by many authors. Jenness and Patton (1959)

discussed the solubility, rate of browning, and combining

11

capacity of casein. Another important aspect of milk, flavor
evaluation, was discussed by Cayen and Baker (1963).

The food uses of commercial casein are rather limited.
In 1967, two thirds of the casein in the United States was
used for industrial uses, mainly as a binder in paper,
paint, and adhesive products (Webb and Whittier, 1970). New
products now being developed and available for consumer use
include filled and imitation milks, coffee whiteners, instant
breakfasts, cereals, sausages and loaves, toppings, ice
cream mixes, sour cream, yoghurt, doughnut mix, and other
foods where it is used to supplement the proteins already
present (Lampert, 1970; Webb and Whittier, 1970). The many
prOperties of casein are advantageous in these various pro-
ducts. Casein hydrolysate, with a fundamental flavor char-
acteristic which suggests meat, is used to accentuate or
suggest the flavor of meat in precooked, cured, stored,
comminuted and dehydrated meats and in dry soup preparations.
In candies, casein forms a firm, resilient, chewy type of
body (Webb and Whittier, 1970). It also improves the body
of sour cream and yoghurt, minimizes shrinkage and improves
overrun in ice cream, and prevents excessive absorption of
fat in doughnuts during deep-fat frying (Lampert, 1970).
In coffee whiteners casein serves in emulsification, whiten-
ing ability, and body and flavor improvement by contributing
its own flavor and reducing the acridity of tannic acids

(Knightly, 1969).

12

The Properties of Whey Proteins

The nutritive value of whey proteins has been known
for many years (Osborne and Mendel, 1924). Their physical
properties were also studied (Peter and Bell, 1930; Black
et al., 1953), but no practical need for the recovery of
whey from the cheese making process was demonstrated. How—
ever, with the present need for an economical waste disposal
system, more cheese plants are now turning to a profitable
whey disposal system. Swanson and Ziemba (1967) described
a process which turns the economic burden of whey waste
disposal into a profitable operation which produces a pro-
duct of high nutritional value. Wingerd (1971) and Wingerd
et al. (1970) found that rats gained more weight on a whey
diet than on a casein diet. Another similar study found
whey and casein had an almost equivalent protein efficiency
ratio (PER) (Anonymous, 1970 b). However, this nutritious
product was only available in an insoluble, gritty, denatured
form which could be used to supplement cereals (Wingerd et al.,
'1970; Wingerd, 1971). It is now available in a bland, sol-
uble form of whey protein concentrate which can coagulate
with other proteins. The functional properties of this pro-
duct - solubility, whipping capacity, emulsification, pH
value, buffer capacity, viscosity - have now been studied by
many (Hansen and Black, 1972; Morr et al., 1973; Kuehler and
Stine, 1974; Richert et al., 1974). These properties could

13

hinder their use in specific products, but they also can
enhance the value of a food if used correctly (Whey Utili-
zation Conference Proceedings, 1970). It is believed that
reverse osmosis may be used to produce high-protein whey
preparations (HPW) at a lower cost than nonfat dried milk.
Another product which would be cheaper than nonfat dried
milk is vegetable protein whey (VPW), which can be obtained
by fortifying whey with a vegetable protein such as soy.
This mixture yielded a sweet product with a flavor of cereal
and milk when reconstituted in water, and had a good storage

life and oxidative resistance.

EXPERIMENTAL PROCEDURES

Exploratory Tests

Exploratory tests were run to determine the best pos—
sible model system for experimentation. The soybean isolates
used were Promine-F and Promine-D, from Central Soya, and
Edi-Pro A and Supro 610, from Ralston Purina Company. The
solvents used were distilled water and a solution designed
to have the salt composition of milk ultrafiltrate (Jenness
and K00ps, 1962). Each soybean isolate was taken in 0.50 to
2.00 g samples and diluted to one hundred ml with either
water or the milk_ultrafiltrate solution (Koops' buffer).
These samples were agitated for one hour at highest speed on
a Burell Wrist—Action Shaker, filtered through Schleicher and
Schuell handfolded S and S American filter paper #605, and
suitable aliquots of the filtrate were taken for micro-
Kjeldahl analysis (McKenzie, 1970), to determine the amount
of soluble protein in the filtrate. Hammarsten casein (Modler,

1973) was prepared and the same solubility tests were run.

14

15

The Model System

Samples of soybean isolate and casein were combined to
a total of 2.5 g/100 ml of K00ps' buffer (5.0 g/200 ml) in a
four hundred ml beaker. Samples of whey protein concentrate
(Enrpro 50, Stauffer Chemical Company), and soybean isolate
were combined to a total of 0.8 g/100 ml of K00ps' buffer
(2.4 g/ 300 ml) in a four hundred ml beaker. These samples
were then stirred for one hour on a ColeJParmer Instrument
Company "magne—4”, model number 4820-4, magnetic stirrer at
setting number nine, and then either subsequently evaluated,
or submitted to either one of three heat treatments ( 1)
145°F/30 minutes, 2) 165OF/flash, 3) 175°F/15 minutes), then
cooled to room temperature in cold water and evaluated. The
first and third heat treatments were achieved by holding in
a water bath for the appropriate time. The second heat treat-
ment was attained by agitating the sample in a boiling water

bath.

Sensory Evaluation

Color and odor were evaluated subjectively and each
sample was compared with the others being tested at the same
time. Any other apparent physical characteristics (clarity,

aggregated materials, etc.) were noted.

16

Viscosity

Viscosity was measured at room temperature (24°C)
with a Brookfield syncho-lectric viscometer, model RVT, at
one hundred rpm using spindle number two. All samples
were used in their entirety in the four hundred ml beakers

in which they were prepared.
Soluble Protein

The concentration of soluble protein present in each
sample was determined by filtering several ml of sample
through Schleicher and Schuell handfolded S and S American
filter paper #605, and removing a suitable aliquot of fil-
trate for a Lowry protein assay (Lowry et al., 1951).
Bovine serum albumin dissolved in distilled water was used
to prepare the standard curve. Absorbance was read at 550
nanometers on a Bausch and Lomb Spectronic 20 spectrophoto-

meter.
Whipping Properties

Twenty-five ml of casein-soy sample or fifty ml of
whey—soy sample was placed in a six hundred ml beaker and
whipped until still peaks of foam formed in the beaker with

a Hamilton Beach Model 97 Mixette on high setting. The

17

height of the foam was measured to determine the volume of
foam produced (Tamsa et al., 1969). The stability of the
foam was measured by filling a fifty ml beaker with foam and
inverting it on a wire screen placed over a funnel. The
amount of drip was measured in a graduated cylinder after
thirty minutes. When the foam was too unstable to fill a
fifty ml beaker, the amount of time it took for the foam in

the six hundred ml beaker to decompose was noted.
Emulsification_

Emulsifying ability was measured as suggested by Webb
et al. (1970). Five ml of casein-soy sample and twenty-five
ml of distilled water or ten ml of whey-soy sample and
twenty—five ml of distilled water_were placed in a four
hundred ml beaker and weighed. The beaker was covered with
a rubber stopper with holes for a stirrer, two electrodes,
and tubing. The beaker was then attached to a Hamilton
Beach malt mixer, number 17 Arnold Model, and the electrodes
attached to a Triplet multimeter, model number 630. Mazola
corn oil was added through the tube to the mixture which was
stirred until the ohmeter read infinite resistance. The
beaker was detached from the apparatus and reweighed to

determine the weight of oil emulsified.

RESULTS AND DISCUSSION
Exploratory Tests

The solubility of Hammarsten casein was the main con-
sideration of the exploratory tests. As reported in Table
1, the casein was almost completely insoluble in water. Con-
sequently, the model system had Koops' buffer as the solvent.
Although four soyprotein isolates exhibited comparable solu-
bilities in K00ps' buffer, Edi-Pro A and Supro 610 were re-
jected because their dispersibility made them difficult to
handle with any accuracy. The method of mixing samples also
proved inefficient; soyprotein isolates tended to float to
the t0p of the volumetric flask and stick in the neck. This
prevented complete mixing of the soyprotein isolate and sol-
vent, giving imprecise results for solubilities. The use of
magnetic stirrers in beakers improved the precision and ac-

curacy of measurement.

Sensory Evaluation

The replacement of casein with soyprotein isolate was
quite apparent visually and by the aroma of the respective
sols. Pure casein mixtures were an opaque white color, with
only a few distinct undissolved particles which sank to the

18

19

Table 1. Preliminary tests for solubility of soyprotein
isolates in distilled water and Koops' buffer.

 

 

 

Protein Protein Solubility
(%) Water (%) Koops' buffer (%)
(W/v) (w/v) (w v)
Promine-F 0.50 12.3 4.2
1.00 19.5 3.5
1.50 16.4 4.0
2.00 18.1 6.0
Promine—D 0.50 34.8 11.3
1.00 14.5 13.5
1.50 43.1 15.4
2.00 33.2 11.1
Edi-Pro A 0.50 1.6 23.4
1.00 0.8 14.5
1.50 0.8 9.4
2.00 0.6 9.2
Supro 610 0.50 10.4 13.2
1.00 10.3 7.7
1.50 13.6 6.6
2.00 . 12.4 7.2
Hammarsten 0.50 1 0 90.5
Casein 1.00 0.0 65.0
1.50 0.0 69.1
2.00 o 3 61.4

 

29
bottom. They exhibited a mild to strong ”gluey" odor de-
pending on the heat treatment. Soyprotein isolate mixtures
appeared cream colored as described in commercial literature.
The undissolved soyprotein isolate formed a layer of the top
of the mixture, and would aggregate and sink to the bottom
during heat treatment. A beany odor was very apparent,
especially after heat treatments. The various mixtures
exhibited the characteristics of both casein and soyprotein
isolate, and as the increments of soyprotein isolate in-
creased and the casein decreased, the properties of the soy-
protein isolate predominated.

The whey protein concentrate (Wpc) mixtures were
similar visually to the soyprotein isolate mixtures. Both
exhibited approximately the same color. However, all the
Wpc appeared to dissolve while the soyprotein isolates again
floated to the top. Wpc mixtures had a cooked milk odor and
the soyprotein isolates had a less intense beany odor than
in higher concentrations. Increasing replacement of Wpc by
soyprotein isolate did not noticeably change the color, but
the floating layer increased and the odor changed from cook—
ed milk to beany. These mixtures also had a pronounced odor.

To date, the objectional flavor of soyprotein isolates
has prevented their use and acceptance in milk substitutes.
Normal milk flavor can be described as very slightly sweet
and salty, not bitter or sour. It has little flavor and_is
not easily characterized. However, off flavors and odors

are easily identified in milk and have been attributed to

21
oxidation, rancidity, sunlight, microbiological deterioration
and absorption of foreign flavors. The distinct cooked
flavor exhibited by the Wpc develops at approximately 74°C
due to the activation of -SH groups from.@-lactoglobulin and
the milk fat membrane proteins to form HZS and other sulfides
(Jenness and Patton, 1959). Wingerd (1971) characterizes
this as a "bland" flavor. Ramshaw and Dunstone (1969)
attributed the gluey off flavor of the casein to non-en-
zymatic browning which develops during storage. The low
level of lactose in the Hammarsten casein reduced browning
to a minimum, thus preventing a very strong flavor and odor
develOpment.

According to Kirimura et al. (1969), the amino acids
and peptides present in a food contribute to its flavor.
Individual amino acids can be characterized as being sweet,
salty, sour, bitter, or MSG-like. Cowan et al. (1973) have
listed the flavor components which they feel are responsible
for the beany and bitter flavors in soyprotein isolates.
Maga (1973) reviewed current work with the flavor of soybean
products, and concluded that while the flavor problem of
soybeans is complex, technological.advances and new instru—
mentation will stimulate research in this area . Badenhop
and Hackler (1970) suggested soaking in NaOH as a pretreat-
ment to improve flavor and mouthfeel. This product must
then be supplemented with methionine to replace nutrients
lost during soaking (Badenhop and Hackler, 1973). Central

Soya Chemurgy Division (a and b) reports a mild alkaline

22
pretreatment of the soybeans before being processed into
isolates. It is this off flavor that will have to be either
removed or masked before the flavor and odor of soyprotein

isolates is acceptable in a bland milk system.

Viscosity

The data in Figure 1 are a plot of the viscosity of
casein and soya sols in Koops' buffer. The protein content
of the solutions was maintained at 2.5% and varied from all
casein to all soya protein. Temperature of heating varied
from none to 175°F/ 15 minutes. In general, the viscosity
of the suspensions decreased with increasing replacement of
the casein by soya protein. The data in Figure 2 show that
the initial viscosity of Wpc and soya protein sols is lower
than observed with casein. A slight increase is noted as
both soyprotein isolate replacements increase. Table 2
presents a statistical analysis of variance of the individual
data points and indicates that the changes are all significant.
However, several factors must be considered when evaluating
these results. Viscosity is defined as the resistance of
liquids to flow or pour. Viscosity is important in milk
because of its relation to milk's "richness". While the
viscosity of milk is a complex property, its normal range
is between 1.5 and 2.0 centipoise at 20°C. Lactose, whey
proteins, and milk salts contribute very little to this,

with the main contribution coming from casein (Jenness and

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Table 2.

25

An analysis of variance for individual data points.

 

 

Source of

Approximate Significant Probability

 

 

Variance
Viscosity Whipping Whipping Emulsification
ability stability

Casginl <0.0005 <o.0005 <0.0005 (0.0005
Soy 3 <0.0005 '<0.0005 0.012 ‘<0.0005
Temperature <0.0005 0.007 0.002 0.015
Casein-Soy <0.0005 0.001 ((0.0005 0.006
Casein-Temp. (0.0005 0.001 1(0.0005 0.676
Soy-Temp. (0.0005 0.072 ' 0.012 0.376
Cas.—Soy-Temp. <0.0005 0.017 0.093 0.299
Wheyl <0.0005 (0.0005 * < 0.0005
Soy 3 <0.0005 < 0.0005 0.130
Temperature <0. 0005 <0. 0005 < 0.0005
Whey-Soy <0. 0005 < 0. 0005 0. 001
Whey-Temp. < 0. 0005 < O. 0005 < 0. 0005
Soy-Temp. (0.0005 4 0.0005 0.033
Whey-Soy-Temp. 4<O.OOO5 140.0005 0.001

 

* Data obtained could not be analyzed.

1 Change in percent

2 Promine-F or Promine-D

3 Change in heat treatment

26
Patton, 1959). As in milk, a very small proportion of
the viscosity was due to the solvent. The Koops' buffer
alone measured a viscosity of 1.04 centipoise. Jenness and
Koops (1962) made no mention of viscosity when describing
it as a milk ultrafiltrate. Nonetheless, the data show
that the viscosities were significantly higher for casein
than for whey protein. Jenness et al. (1965) state that
viscosity depends on temperature, and amount and state of
dispersion of solid constituents. This was evident when
measuring the viscosity of the sols because casein mixtures,
with more dissolved particles in solution had a greater
viscosity than soyprotein isolate mixtures. The soyprotein-
isolate aggregates made the viscosity reading higher for

whey mixtures.
Soluble Protein

The concentration of soyprotein isolate in the buffer
system had a substantial effect on the soluble protein pre-
sent in the mixture. Figure 3 shows that casein was almost
completely soluble in K00ps' buffer while both soyprotein
isolates were much more dispersible than soluble. An almost
linear relationship exists in the decline of the amount of
casein and decrease in the amount of soluble protein present.
In the case of the Wpc-soya mixtures in which total protein
content was lower, there was very little decrease in the

amount of soluble protein present with increasing soyprotein

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27

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28
isolate replacement of Wpc, as seen in Figure 4. No sta-
tistical analysis was available for these data because
there was no variance among observations for individual data
points.

A protein is considered soluble when the attraction of
individual molecules for the solvent is greater than that
between the protein molecules. Since solubility depends
on both pH and salt concentration, minimum solubility is
at the isoelectric point of the protein with no salts present.
Here there is a maximum attraction of the positive and
negative forces of adjacent protein molecules. As the pH
increases or decreased from the isoelectric point, a net
positive or negative charge deve10ps on the protein molecules
and they are attracted to the water m01ecules, causing the
protein to dissolve. At low concentrations of neutral salts
there is an increased net charge and increased protein
solubility. However, at very high salt concentrations the
ions compete with the protein for attraction with the water
molecules, and protein solubility decreases. Casein binds

Ca++

and other bivalent cations very tenaciously at pH values
alkaline to the isoelectric point which causes aggregation
and decreased solubility. Whey proteins are solublized by
a small concentration of neutral salts or small changes in
pH (Jenness and Patton, 1959). Gordon and Whittier (1965)
point out that the amount of casein dissolved by many sol—

vents varies with the quantity of casein added to a definite

quantity of solvent, so that many available data on casein

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29

 

 

 

 

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solubility have limited uses. This results from the fact
that most casein preparations consist of more than one
molecular species. However, casein can be dissolved in
aqueous solutions of acids, alkalies, and alkaline salts
such as the potassium, calcium, and magnesium chlorides
which are present in Koops' buffer. Since this solvent
has the same pH, salt content and ionic strength as milk
ultrafiltrate, the casein is almost completely soluble in it.

Both soyprotein isolates used are considered water dis-
persible (Central Soya Chemurgy Division, a and b) with 65%
of Promine-F and 75% of Promine-D water soluble. Williams
(1972) and Wolf (1972) state that soyprotein isolates are
fairly insoluble, but that solubility can be increased by
adding 0.01 mercaptoethanol to the solvent. This breaks
most of the disulfide cress-links which cause polymerization
and thus insolubility during isoelectric precipitation. A
portion of the isolate still remains insoluble after adding
mercaptoethanol. Wolf (1972) cautions that commercial
isolates vary in solubility due to processing variations.
Chakraborty and Hansen (1969) and Sugimoto and Van Buren (1971)
suggested that carbohydrates be added to milk—soy systems
not to increase solubility, but to stabilize the dispersions.

Data from Stauffer Chemical Company and Morr et al. (1973)
agree that Wpc is almost totally soluble in the pH and ionic

strength range of Koops' buffer.

31
Whipping Pronerties

The replacement of casein with soyprotein isolate appear-
ed to have very little effect on whipping ability except for
a slight decrease in the case of pure soy mixtures, as seen
in Figure 5.. Whey mixtures also appeared to maintain their
whipping ability, except for 0.2% Wpc, 0.6% soyprotein iso—
late, which has the least amount of protein present and
formed the least amount of foam (Figure 6). All of these
values appear to be statistically significant (Tableaz). In
spite if their fairly stable whipping ability, the whip-
ping stability of the casein-soy mixtures was greatly af-
fected by the introduction of soya pr0tein. Even though the
same amount of foam was formed, the foam stability-decreased
with increasing concentration of soya isolate, as can be
seen in Figure 7. Table 2 shows this is also statistically
sound. The Wpc and soyprptein isolate mixtures were so un-
stable that drip could not be measured, and they could not be
evaluated statistically. Table 3 shows the amount of time
it took for the foam to completely collapse. The pure soy-
protein isolate mixtures were stable enough to measure drip,
showing increasing foam stability with increasing soyprotein
isolate replacement of this low level of protein.

According to Morr et al. (1973) nonfat dried milk, with
casein as its main protein, appears superior to whey proteins

for formulating a whipped topping mix. Tamsa et al. (1969)

32

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35

 

 

Table 3. The whipping stability of Promine—F and Promine—D
replacements of Wpc in K00ps' buffer.
Percent Composition Heat Whipping Stability

 

 

(g/100 ml Koops') Treatment (min. or ml) (min. or ml)

Wpc Soybean Promine-F Promine-D
isolate

0.8 0.0 none 5 3

0.6 0.2 5 3-4

0.4 0.4 5 3-4

0.2 0.6 5 3-4

0.0 0.8 5.2 9.3

0.8 0.0 145°F/30min. 5-10 5-10

0.6 0.2 5-10 10-15

0.4 0.4 15-20 10-15

0.2 0.6 10.7 35-40

0.0 0.8 6.4 6.9

0.8 0.0 165°F/flash 15-20 15-20

0.6 0.2 5-10 5-10

0.4 0.4 10-15 50-55

0.2 0.6 12.9 60-65

0.0 0.8 6.5 10.1

0.8 0.0 175°E/15min. 5-10 5-10

0.6 0.2 10-15 15-20

0.4 0.4 40-45 30-35

0.2 0.6 12.7 65-70

0.0 0.8 '5.3

 

36
also agreed that nonfat dried milk can be whipped into a
stable foam. Hansen and Black (1972) found that whey protein
whipped best when mixed with nonfat dried milk. However,
the lower cost of whey proteins and soyprotein isolate has
led toward their use in food products, but in mixtures with
a much higher percent than tested here. Eldridge et al.
(1963) found that soybean protein can form stable whips both
above and below the isoelectric point. Both heating and in-
creasing protein concentration enhance foam stability. '
Yasumatsu et al. (1972 b) found that soy proteins exhibit
poor foam stability in spite of their high foam expansion
because of their denaturation during processing. Central
Soya Chemurgy Division (b) suggests Promine-F has excellent
overrun qualities and good stability comparable to sodium
caseinate, but this was shown not to be the case at a level
of 2.5%.

Apparently the amount of Wpc used was much too low for
good whipping properties. Kuehler and Stine (1974) found
good whipping ability and stability on 4% Wpc sols. Morr
et al. (1973) made toppings with 27% total solids. Richert
et al. (1974) also used 4% protein solutions. They found
that severe heat treatment required longer whipping times
and produced lower overrun foams with highly variable sta-
bility. Whey Utilization Conference Proceedings (1970) also

recommended 38% whey solids to produce 200 to 300% Overrun.

37

Emulsification

The emulsifying capacity of casein-soy protein mixtures
also decreases as soy protein increases in the mixture. As
seen in Figure 8, there is an increase in emulsion ability
for Promine-F which maximizes at 1.5% casein, 1.0% soy-
protein isolate, and then it decreases sharply. However,
from the analysis of variance of the data, Table 2, an
extremely wide variance is found among the data, and their
validity is in doubt. It was extremely difficult to control
the amount of undissolved material that went into the al-
iqout being tested, and more of this material would result
in a higher amount of oil being used. The emulsions used
were also extremely thick, and it was difficult to judge
exactly when complete emulsification was achieved. The data
for Promine-D and the Wpc mixtures are much more reliable.
The ability of Wpc mixtures to emulsify decreased significant-
ly as soyprotein increased. An additional test with coconut
oil, which is a saturated fat, was tried with casein and Wpc
mixtures with Promine-F with no heat treatment. Figure 10
shows a significant decrease in the amount of oil emulsified,
but it is difficult to determine if this is due to the
saturation of the fat or to the necessity to use this oil
at 92°F to keep it melted, and its consequent hardening upon
mixing with the room temperature sample.

Casein is not a widely used emulsifying agent. Both

 

 

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41
pure casein and nonfat dried milk show a lower emulsifying
capacity than whey protein (Kuehler and Stine, 197k). This
would be seen of casein and whey had been teated at the same
concentrations. However, the replacement of both with soy-
protein isolate resulted in thinner emulsions. Central Soya
Chemurgy Division (a and b) recommends both Promine—F and
Promine—D as emulsifying agents, but it appears that a
mixture of casein and these isolates would form a better

product.

SUMMARY AND CONCLUSION

1. Sensory evaluation revealed a significant change
in flavor as casein sols were replaced with increasing
amounts of soyprotein isolate. The color changed from opaque
white to a cream white with noticeable aggregation. The odor
changed from gluey to beany. No color change was evident
on replacing Wpc with soyprotein isolate, but aggregation
was apparent. The odor changed from cooked milk to beany.
No new color or odor, signifying protein interactions,
appeared.

2. Viscosity decreased with replacement of casein by
soyprotein isolate, and increased slightly with replacement
of Wpc. No significant deviation appeared to indicate
interaction of proteins.

3. The amount of soluble protein present greatly de-
creased as soyprotein isolate replaced casein, but remained
fairly constant as Wpc was replaced. An almost linear rela-
tionship indicated no protein interaction.

#. Whipping ability appeared to change very little
with either replacement. Whipping stability decreased
greatly for soyprotein isolate replacement of casein, but
improved for replacement of Wpc. No protein interactions
were apparent.

5. Emulsification ability of both casein and Wpc

42

43
decreased with increasing replacement by soyprotein isolate.
The increase noted in Promine-F and soyprotein isolate is
apparently due more to difficulty in procedure than any

protein interactions.

The apparent lack of interaction between the casein,
Wpc, and soyprotein isolates suggests that these proteins
are compatible in a fluid system. However, such problems as
color, odor, flavor, viscosity, etc. will have to be over-
come before their use as a milk-type product could gain

consumer acceptance.

LITERATURE C ITED

LITERATURE CITED

Altschul, A. M. 1967. Food proteins: new sources from seeds.
SCiO ’ 128, 2210

Anonymous. 1963. Appraisal of nutritional adequacy of infant
formulas used as cow milk substitutes, report for the
committee on nutrition. Pediatrics, 3;, 329.

Anonymous. 1968. Milk substitues gaining wide acceptance.
Food Proc., 22, 21.

Anonymous. 1970 a. Soy beverage process. Food Eng., 3;, 92.

Anonymous. 1970 b. Cost reducing whey solids are high in
nutritional value. Food Prod. Devel., 3, 100.

Anonymous. 1971. IFT Industrial Award. Food Tech., 25, 59h.

Anonymous. 1972. 'Good tasting' soy products, foods of
tomorrow. Food Proc., summer 1972, F7. .

Anonymous. 1973. Commercial production of Miltone ex-
panded. Food Tech., 22, 58.

Badenhop, A. F. and Hackler, L. R. 1970. Effects of soak-
ing soybeans in sodium hydroxide solution as pretreat-
ment fro soy milk production. Cer. Sci. Today, 15, 8h.

Badenhop, A. F. and Hackler, L. R. Methionine supplementation
of soy milk to correct cystine loss resulting from an
alkaline soaking procedure. J. Food Sci., 8, 471.

Belshaw, F. 1971. Protein isolate is stable to pH 2.0,
Food Proc., 3g, 17. ‘

Block, R. J., Bolling, D., Weiss, K. W., and Zweig, G. 1953.
Studies on bovine whey proteins. Arch. Biochem. Biophy.,

£2, 88.
Bockwalter, G. N., Moser, H. A., Black, L. T., and Griffin,

E. L., Jr. 1971. CSM: increasing fat to 6% in corn-
soy-milk blends. J. Food Sci., , 737.

an

45

Brink, M. F., Balsley, M., and Speckman, E. W. 1969.
Nutritional value of milk compared with filled and
imitation milks. Am. J. Clin. Nutr., 22, 168.

Cayen, M. N., and Baker, B. E. 1963. Some factors affecting
the flavor of sodium caseinate. J. Agr. Food Chem.,

11, 12.

Central Soya Chemurgy Division a. Promine-D, Technical Ser-
vice Manual.

Central Soya Chemurgy Division b. Promine—F, Technical Ser-
vice Manual.

Chakraborty, B. K. and Hansen, P. M. T. 1969. Stabilization
of soyprotein isolates in milk salt systems. J. Dairy
Sci., 52, 886.

Chandrasekhara, M. R. 1968. Extension of milk resources
with vegetable proteins. Indian Food Packer, 22, 1.

Chandrasekhara, M. R., Ramanna, B. R., Jaganneth, K. S. and
Ramanathan, P. K. 1971. Miltone vegetable tonned pro—
tein. Food Tech., 25, 596.

Childers, A. B. 1972. Vegetable protein foods - a review.
J. Milk Food Tech., 35, 604.

Collins-Williams, C. 1956. Clinical studies with powdered
Sobee, a new milk substitute. Can. Med. Assoc. J., 25,

934.

Council on Foods and Nutrition, AMA. 1969. Substitutes for
whole milk. J. Am. Med. Assoc., 208, 1686.

cowan’ J. C o , RaCKiS , Jo J. g and WOlf’ W. Jo 19730 soy-
bean protein flavor components - a review. J. Am. Oil
Chem. Soc., 59, 426A.

Eldridge, A. C., Hall, P. K., and Wolf, W. J. 1963. Stable
foams from unhydrolyzed soybean protein. Food Tech., 12,

1592.

Foman, S. J. ’ Gwen, G. M. p and Thomas, L. No 196“. MGthi-
onine, valine, and isoleucine. Am. J. Diseases Child.,
108, 487.

Fujimaki, M., Kato, H., Ara, S., and Tamaki, E. 1968.
Applying proteolytic enzymes on soybean. Food Tech., 22,
889.

46

Gorden, W. G. and Whittier, E. 0. 1965. Proteins of milk.
in Fundamentals of Dairnyhemistry. Webb, B. H. and
Johnson, A. H., ed. The Avi Publishing Company.
Westport, Conn.

Hansen, P. M. T. and Black, D. H. 1972. Whipping properties
of spray-dried complexes from whey protein and carboxy-
methylcellulose. J. Food Sci., 32, 452.

Hartman, A. M. and Dryden, L. P. 1965. Vitamins in Milk and
Milk Products. Am. Dairy Sci. Assoc.

Holland, R. F. 1968. How to make imitation milk. Am. Dairy
Rev., 39, 78.

Holland, R. F. 1969. Nutritional values of filled and
imitation milks. Am. Dairy Rev., 31, 60.

Holt,62. E.6 1965. The prevention of eczema. J. of Ped.,
_,22.

Howard, H. W., Block, R. J., Anderson, D. W., and Bauer, C.
D. 1956. The effect of longtime feeding of soybean
iggant food diet to white rats. Annals of Allergy, 14,
1 .

Inglett, G. E., Blessin, C. W., and Bockwalter, G. N. 1968.
Flavor aspects of cereal-oilseed—based food products.
Food Prod. Devel., 2, 66.

Ioanes, R. A. 1973. Soybeans: US challenge and cppurtunity.
' Foreign Agr., 3.

Jacobsen, R. E. 1969. Economics of imitation milk pro-
ducts. J. Dairy Sci., 52, 751.

Jenness, R. and Koops, J. 1962. Preparation and properties
of a salt solution which simulates milk ultrafiltrate.
Neth. Milk Dairy J., 16, 153.

Jenness, R. and Patton, S. 1959. Principles of Dairy Chem-
istry. John Wiley and Sons, Inc., New York.

Jenness, R., Shipe, W. F., and Whitnah, C. H. 1965 Physical
properties of milk in Fundamentals of Dairy Chemistry.
Webb, B. H. and Johnson, A. H., ed. The Avi Publishing
Company, Westport, Conn.

Johnson, D. W.-and Circle, S. J. 1959. Multi-purpose
qualigy protein offers ”plus factors". Food Proc.,
2.9.3.

47

Kay, J. L., Daeschner, C. W., and Desmond, M. M. 1960.
Evaluation of infants fed soybean and evaporated milk
formulae from birth to three months. Am. J. Diseases
Child., 122, 264.

Kirimura, J., Shimizu, A., Kimizuka, A. Ninomiya, T., and
Katsuya, N. 1969. The contribution of peptides and
amino acids to the taste of foodstuffs. J. Agr. Food
Chem., 12, 689.

Knightly, W. H. 1969. The role of ingredients in the for-
mulation of coffee whiteners. Food. Tech., _3, 171.

Kon, S. K. 1972. Milkfiand Milk Products in Human Nutrition.
Food and Agriculture Organization of the United Nations,
Rome.

Kosikowski, F. V. 1969. Role of imitation milk in the feed-
ing of tomorrow's population. J. Dairy Sci., 52, 756.

Koskowski, F. V. 1968. The problems of milk and imitation
milk. J. Milk Food Tech., 21, 174.

Kuehler, C. A. and Stine, C. M. 1974. Effect of enzymatic
hydrolysis on some functional propertied of whey pro-
tein. J. Food Sci., 32, 379.

Lampert, L. M. 1970. Modern Dairy Products. Chemical Pub-
lishing Co., Inc., New York.

Lowry, 0. H., Rosenbrough, N. J., Farr, A. L., and Randall,
R. J. 1951. Protein measurement with the folin phenol
reagent. J. Biol. Chem., 123, 265.

Lyster, R. L. J. 1972. Reviews of the progress of dairy
science. Section C. Chemistry of milk proteins. J.
Dairy Rev., 32, 279.

Maga, J. A. 1973. A review of flavor investigations as-
sociated with the soy products raw soybeans, defatted
flakes and flours, and isolates. J. Agr. Food Chem.,

_2_1, 864.

McKenzie, H. A. and Murphy, W. H. 1970. General methods
and elemental analysis in Milk Proteins - Chemistry and
Molecg1ar Biology, Vol. 1, McKenzie, H. A., ed.
Academic Press, New York

Modler, H. W. 1973. The isolation and characterization of
the extracellular protease penicillium roqueforti BP-13.
Ph. D. Thesis, Michigan State University.

48

Morr, C. V., Swenson, P. E., and Richter, R. L. 1973.
Functional characteristics of whey protein concentrates.
J. Food Sci., 32, 324.

Moses, W. R. 1969. Imitation dairy products - federal laws
and regulations. J. Dairy Sci., 52, 748.

Mustakas, G. C., Albrecht, W. J., Bookwalter, G. N., Sohns,
V. E., and Griffin, E. L., Jr. 1971. New process for
log-cost, high protein beverage base. Food Tech., 25,
53 -

Nelson, A. I., Wei, L. S., and Steinberg, M. P. 1971.
Food products from whole soybeans. Soybean Digest, 311

32.

Noyes, R. 1969. 2rote1n Food Supplements, Food Processing
Review #3. Noyes Development Corp., Park Ridge, New

Jersey.

 

Osborne, T. B., and Mendel, L. B. 1924. The nutritive value
of lactalbumin. J. Biol. Chem., 52, 13.

Peter, P. N. and Bell, R. W. 1930. Normal and modified
foaming properties of whey-protein and egg-albumin
solutions. Ind. Eng. Chem., 22, 1124.

Ramshaw, E. H. and Dunstone, E. A. 1969. The flavour of
milk protein. J. Dairy Rev., 35, 203.

Richert, S. H., Morr, C. V., and Cooney, C. M. 1974.
Effect of heat and other factors upon foaming properties
of whey protein concentrates. J. Food Sci., 32, 2.

Rose, D. 1969. A proposed model of micelle structure in
bovine milk. Dairy Sci. Abs., 31, 171.

Shih, V. E. 1970. A low-methionine substitute for cow's
milk for children and adults. J. Am. Diet. Assoc., 52,
520.

Standal, B. R. and Kian, H. G. 1968. Nutritive quality-of
simulated milk mixtures prepared from tropical pro-
ducts. J. Food Sci., 33, 426.

Stauffer Chemical Co., Energy Products Department. ENRPRO
50 Modified Whey Solids, a flyer. 7506 Washington Ave.
South, Edina, Minn.

Sugimoto, H. and Van Buren, J. P. 1971. Evaluation of mono—
saccharides, disaccharides, and corn syrups as dis-
persants for heat processed dried sOy milk products.

J. Food Sci., 35, 346.

49

Swanson, E. and Ziemba, J. V. 1967. Seek more profits
from plant wastes. Food Eng., 32, 110/

Tamsa, A. , Konston, A., and Pallansch, M. J. 1969 Pro-
duction of whippable nonfat dried milk by homogenization.
J. Dairy Sci., 52, 428.

Theuer, R. C. and Sarett, H. P. 1970. Nutritional adequacy
of soy isolate infant formulas in rats: choline. J.
Agr. Food Chem., 12, 913.

Thompson, M. P., Tarassuk, N. P., Jenness,.R., Lillefiik,-H. A.,
Ashworth, V. S. , and Rose, D. 1965. Nomenclature of
the proteins of cow's milk - second revision. J. Dairy
Sci., 48,159

Tiling, W., Ehring, A. M., and Stewart, C. D. 1961. The
use of soya based foods in infant feeding. Nutritio
et Dicto, 3, 89.

USDA. 1969. Synthetic and substitutes for agricultural
products. Economics research service. Miscellaneous
publication no. 1141. US Government Printing Office,
Washington, D. C.

Webb, N. B., Ivey, F. J. Craig, H. B., Jones, V. A., and
Monroe, R. J. 1970. The measuring of emulsifying
capacity by electrical resistance. J. Food Sci., 35,
501.

Webb, B. H., and Whittier, E. O. 1970. Byproducts from Milk.
The Avi Publishing Co., Inc., Westport, Conn.

Whey Utilization Conference Proceedings. 1970. University
of Maryland and USDA, College Park, MD.

Williams, L. D. 1972. Composition, properties, and chemistry
of edible soy proteins. La Rivista Italiana Delle
Sostanze Grasse, _2, 330.

Wingerd, W. H., Saperstein, S., and Lutwak, L. 1970. Bland,
soluble whey protein concentrate has excellent nutritional
properties. Food Tech. , 24, 758. '

Wolf, W. J. 1972. What is soy protein? Food Tech., 22, 52.

Yasumatsu, K., Toda, J., Aoki, H., Wada, T., and Ishii, K.
1972 a. Studies on the functional properties of food-
grade soybean products, Part II, flavor profile. Agr.
Biol. Chem., 3_, 532.

50

Yasumatsu, K., Sawada, K., Moritaka,S., Misaki, M., Toda, J.,
Wada, T., and Ishii, K. 1972 b. Whipping and emulsi-
fying properties of soybean products. Agr. Biol. Chem.,
3a. 719.

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