• TABLE OF CONTENTS
HIDE
 Copyright
 Front Cover
 Table of Contents
 Experimental procedure and...
 General discussion
 Practical recommendations
 Conclusions
 Literature cited






Group Title: Bulletin - University of Florida. Agricultural Experiment Station - no. 402
Title: Manufacture of ice cream with limited milk solids
CITATION PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027533/00001
 Material Information
Title: Manufacture of ice cream with limited milk solids
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 30 p. : ; 23 cm.
Language: English
Creator: Freeman, T. R ( Theodore Russell ), 1906-
Fouts, E. L ( Everett Lincoln ), b. 1890
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1944
 Subjects
Subject: Ice cream, ices, etc   ( lcsh )
Food substitutes   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 30.
Statement of Responsibility: T.R. Freeman and E.L. Fouts.
General Note: Cover title.
Funding: Bulletin (University of Florida. Agricultural Experiment Station) ;
 Record Information
Bibliographic ID: UF00027533
Volume ID: VID00001
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: aleph - 000925210
oclc - 18232143
notis - AEN5857

Table of Contents
    Copyright
        Copyright
    Front Cover
        Page 1
        Page 2
        Page 3
    Table of Contents
        Page 4
    Experimental procedure and results
        Page 5
        Preliminary studies with various products
            Page 5
            Page 6
            Page 7
            Page 8
        Oat flour studies
            Page 9
        Preliminary studies with general purpose (blended) wheat flour
            Page 10
            Effect of varying flour content at different serum solids levels
                Page 10
                Page 11
                Page 12
                Page 13
            Wheat flour as a stabilizer
                Page 14
            Addition of salt to flour mixes
                Page 14
                Page 15
        Studies with different grades of wheat flour
            Page 16
            Acidity and viscosity of mix
                Page 16
            Whipping properties of mix and melting resistance of ice cream
                Page 17
                Page 18
            Relationship of grade of wheat used to palatability of ice cream
                Page 19
        Processing methods for wheat flour mixes
            Page 19
            Page 20
            Method of adding flour
                Page 21
            Pasteurization temperature
                Page 22
                Page 23
        The testing of mixes containing flour
            Page 24
            Page 25
        Flour in sherbets
            Page 26
    General discussion
        Page 26
        Page 27
    Practical recommendations
        Page 28
    Conclusions
        Page 29
    Literature cited
        Page 30
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida






October, 1944


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
HAROLD MOWRY, Director
GAINESVILLE, FLORIDA











MANUFACTURE OF ICE

CREAM WITH LIMITED

MILK SOLIDS


T. R. FREEMAN and E. L. FOUTS









Single copies free to Florida residents upon request to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA


Bulletin 402










BOARD OF CONTROL
H. P. Adair. Chairman, Jacksonville
N. B. Jordan, Quincy
T. T. Scott, Live Oak
Thos. W. Bryant, Lakeland
M. L. Mershon, Miami
J. T. Diamond, Secretary, Tallahassee

EXECUTIVE STAFF
John J. Tigert, M.A., LL.D., President of the
University'
I. Harold Hume, D.Se., Provost for Agricul-
ture
Harold Mowry, M.S.A., Director
L. O. Gratz, Ph.D., Asst. Dir., Research
W. M. Fifield. M.S., Asst. Dir., Admin.4
J. Francis Cooper, M.S.A., Editor*
Clyde Beale, A.B.J., Assistant Editors
Jefferson Thomas, Assistant Editor'
Ida Keeling Cresap, Librarian
Ruby Newhall. Administrative Managers
K. H. Graham, LL.D., Business Managers
Claranelle Alderman, Accountants

MAIN STATION. GAINESVILLE
AGRONOMY
W. E. Stokes, M.S., Agronomist1
Fred H. Iull, Ph.D., Agronomist
G. E. Ritchey, M.S., Agronomist'
W. A. Carver, Ph.D., Associate
Roy E. Blaser, M.S., Associate
G. B. Killinger, Ph.D., Agronomist
H. C. Harris, Ph.D., Associate
R. W. Bledsoe, Ph.D., Assistant
Fred A. Clark, B.S.. Assistant

ANIMAL INDUSTRY
A. L. Shealy, D.V.M., An. Industrialist' s
R. B. Becker, Ph.D., Dairy Husbandman'
E. L. Fonts, Ph.D., Dairy Technologist"
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian'
L. E. Swanson, D.V.M., Parasitologist'
N. R. Mehrhof, M.Agr., Poultry Hush.s
T. R. Freeman, Ph.D., Asso, in Dairy Mfg.
. S. Glasscock, Ph.D., An. Husbandman
D. J. Smith. B.S.A., Asst. An. Hush.'
P. T. Dix Arnold, M.S.A., Asst. Dairy Hush.'
G. K. Davis, Ph.D., Animal Nutritionist
C. L. Comar, Ph.D., Asso. Biochemist
L. E. Mull, M.S., Asst. in Dairy Tech.'
O. K. Moore, M.S., Asst. Poultry Hush.'
J. E. Pace, B.S., Asst. An. Husbandman4
S. P. Marshall, M.S., Asst. in An. Nutrition

ECONOMICS, AGRICULTURAL

C. V. Noble, Ph.D., Agr. Economistx
Zach Savage, M.S.A., Associate'
A. H. Spurlock, M.S.A., Associate
Max E. Brunk, M.S.. Assistant


ECONOMICS, HOME

Ouida D. Abbott, Ph.D., Home Econ.'
Ruth O. Townsend, R.N., Assistant
R. B. French, Ph.D., Biochemist


ENTOMOLOGY

J. R. Watson, A.M., Entomologist1
A. N. Tissot, Ph.D., Associates
H. E. Bratley, M.S.A., Assistant


HORTICULTURE

G. H. Blackmon, M.S.A., Horticulturist'
A. L. Stahl, Ph.D., Asso. Horticulturist
F. S. Jamison, Ph.D., Truck Hort.
R. J. Wilmot, M.S.A., Asst. Hort.
R. D. Dickey, M.S.A., Asst. Hort.'
J. Carlton Cain, B.S.A., Asst. Hort.'
Victor F. Nettles, M.S.A., Asst. Hort.'
Byron E. Janes, Ph.D., Asst. Hort.
F. S. Lagasse, Ph.D., Asso. Hort.'
H. M. Sell, Ph.D., Asso. Horticulturist'


PLANT PATHOLOGY

W. B. Tisdale, Ph.D., Plant Pathologisti
Phares Decker, Ph.D., Asso. Plant Path.
Erdman West, M.S., Mycologist
Lillian E. Arnold, M.S., Asst. Botanist



SOILS

F. B. Smith, Ph.D., Chemistl '
Gaylord M. Volk, M.S., Chemist
L. E. Ensminger, Ph.D., Soils Chemist
J. R. Henderson, M.S.A., Soil Technologist
J. R. Neller, Ph.D., Soils Chemist
C. E. Bell, Ph.D., Associate Chemist
L. H. Rogers, Ph.D., Associate Biochemist'
R. A. Carrigan, B.S., Asso. Biochemist'
G. T. Sims, M.S.A., Associate Chemist
T. C. Erwin, Assistant Chemist
H. W. Winsor, B.S.A., Assistant Chemist
Geo. D. Thornton, M.S., Asst. Microbiologist
R. E. Caldwell, M.S.A., Asst. Soil Surveyor'
Olaf C. Olson, B.S., Asst. Soil Surveyor



x Head of Department.
2 In cooperation with U. S.
a Cooperative, other divisions, U. of F.
4 In Military Service.
SOn leave.















BRANCH STATIONS
NORTH FLORIDA STATION, QUINCY

J. D. Warner, M.S., Vice-Director in Charge
R. R. Kincaid, Ph.D., Plant Pathologist
V. E. Whitehurst, Jr., B.S.A., Asst. An. Hush.4
W. C. McCormick, B.S.A., Asst An. Hush.
Jesse Reeves, Asst. Agron., Tobacco
W. H. Chapman, M.S., Asst. Agron.'
R. C. Bond, M.S.A., Asst. Agronomist

Mobile Unit, Monticello
R. W. Wallace, B.S., Associate Agronomist

Mobile Unit, Milton
Ralph L. Smith, M.S., Associate Agronomist

Mobile Unit, Marianna
R. W. Lipscomb, M.S., Associate Agronomist


CITRUS STATION, LAKE ALFRED

A. F. Camp, Ph.D., Vice-Director in Charge
V. C. Jamison, Ph.D., Soils Chemist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Entomologist
W. W. Lawless, B.S., Asst. Horticulturist4
C. R. Stearns, Jr., B.S.A., Asso. Chemist
H. O. Sterling, B.S., Asst. Horticulturist
T. W. Young, Ph.D., Asso. Horticulturist
J. W. Sites, M.S.A., Asso. Horticulturist


EVERGLADES STA., BELLE GLADE

R. V. Allison, Ph.D., Vice-Director in Charge
J. W. Wilson, Sc.D., Entomologist'
F. D. Stevens, B.S., Sugarcane Agron.
Thomas Bregger, Ph.D., Sugarcane
Physiologist
G. R. Townsend, Ph.D., Plant Pathologist
R. W. Kidder, M.S., Asst. An. Hush.
W. T. Forsee, Jr., Ph.D., Asso. Chemist
B. S. Clayton, B.S.C.E., Drainage Eng.'
F. S. Andrews, Ph.D., Asso. Truck Hort.'
R. A. Bair, Ph.D., Asst. Agronomist
E. C. Minnum. M.S., Asst. Truck Hort.
N. C. Hayslip, B.S.A., Asst. Entomologist


SUB-TROPICAL STA., HOMESTEAD

Geo. D. Ruehle, Ph.D., Vice-Director in
Charge
P. J. Westgate, Ph.D., Asso. Horticulturist
H. I. Borders, M.S., Asso. Plant Path.


W. CENT. FLA. STA., BROOKSVILLE

Clement D. Gordon, Ph.D., Asso. Poultry
Geneticist in Charge2

RANGE CATTLE STA., ONA

W. G. Kirk, Ph.D., Vice-Director in Charge
E. M. Hodges, Ph.D., Asso. Agron., Wauchula
Gilbert A. Tucker, B.S.A., Asst. An. Hush.'


FIELD STATIONS

Leesburg
M. N. Walker, Ph.D., Plant Path. in Charge'

Plant City
A. N. Brooks, Ph.D., Plant Pathologist

Hastings
A. H. Eddins, Ph.D., Plant Pathologist
E. N. McCubbin, Ph.D., Truck Horticulturist

Monticello
S. O. Hill, B.S., Asst. Entomologists
A. M. Phillips, B.S., Asst. Entomologists

Bradenton

J. R. Beckenbach, Ph.D., Horticulturist in
Charge
E. G. Kelsheimer, Ph.D., Entomologist
D. B. Creager, Ph.D., Plant Path., Gladiolus
A. L. Harrison, Ph.D., Plant Pathologist
David G. Kelbert, Asst. Plant Pathologist
E. L. Spencer, Ph.D., Soils Chemist

Sanford

R. W. Ruprecht, Ph.D., Chemist in Charge
J. C. Russell, M.S., Asst. Entomologists

Lakeland

E. S. Ellison, Meteorologist's
Warren O. Johnson, Meteorologists

Head of Department.
2In cooperation with U. S.
s Cooperative, other divisions, U. of F.
SIn Military Service.
5 On leave















CONTENTS
Page
EXPERIMENTAL PROCEDURE AND RESULTS-----....................... -------------- 5

I. Preliminary Studies with Various Products----................................----.... 5

II. Oat Flour Studies .................... ............. -.... .. 9

III. Preliminary Studies with General Purpose (Blended)
Wheat Flour .... ------............... ---... -- --- .......................... ... 10
1. Effect of Varying Flour Content at Different Serum
Solids Levels ........................... ... ................. 10
2. W heat Flour as a Stabilizer .............................. .............. 14
3. Addition of Salt to Flour M ixes ............................................ 14

IV. Studies with Different Grades of Wheat Flour ............................ 16
1. Acidity and Viscosity of Mix ..........................-............ .. 16
2. Whipping Properties of Mix and Melting Resistance
of Ice Cream .............. ..... ...................................... 17
3. Relationship of Grade of Wheat Flour Used to
Palatability of Ice Cream ........................................................ 19

V. Processing Methods for Wheat Flour Mixes ..............................-. 19
1. Method of Adding Flour --..................... .................... -21
2. Pasteurization Temperature .......................-.......... .. -------22

VI. The Testing of Mixes Containing Flour ........................................ 24

VII. Flour in Sherbets ................ -------------------........ 26

GENERAL DISCUSSION ...................................... ----- -------..-- 26

PRACTICAL RECOMMENDATIONS ............ ....... ........- .-------------. 28

CONCLUSIONS ........ ............. ................ --- --.............. 29

LITERATURE CITED ............................---- ..----------- ------------------ 30








MANUFACTURE OF ICE CREAM

WITH LIMITED MILK SOLIDS
T. R. FREEMAN and E. L. FOUTS

Ice cream manufacturers, like individuals in all other indus-
tries, have been handicapped by shortages of raw materials
since the entrance of this nation into active participation in
World War II. Sugar, vanilla and chocolate were among the
first ice cream ingredients of major importance to be curtailed.
A year later milk solids became scarce, resulting in government
regulations concerning the use of such solids in ice cream. Pre-
vious publications from this laboratory have dealt with the
problem of sweeteners (3, 4)1. This bulletin is a report on
experiments dealing with the problem of manufacturing ice
cream with limited supplies of milk solids.
In 1942 the impending shortage of milk solids became appar-
ent, although the probability of government restrictions on the
use of such solids in ice cream had not yet been intimated.
However, in the latter part of 1942 the situation became acute,
and it was obvious that less milk-solids-not-fat would be avail-
able for use in ice cream. Accordingly, investigations were
begun in December of that year, to search for pure food materials
that could be used for improving the body and texture of ice
cream containing reduced quantities of milk solids.

EXPERIMENTAL PROCEDURES AND RESULTS
I.-PRELIMINARY STUDIES WITH VARIOUS PRODUCTS
Having in mind the factors of availability, cost and probable
suitability for use in ice cream, it was decided that cereal
products should be the subject of preliminary trials. Of the
many cereal products available, it was believed that a number
would be definitely unsuitable for 1 or more reasons. Such fac-
tors as solubility, flavor, color, effect on viscosity and effect on pH
might be involved. To eliminate those substitutes which were
obviously unsatisfactory, preliminary "weeding out" trials were
conducted.
For this purpose small laboratory mixes were prepared. The
method of processing followed closely that used commercially,

1Italic figures in parentheses refer to Literature Cited in the back of
this bulletin.








MANUFACTURE OF ICE CREAM

WITH LIMITED MILK SOLIDS
T. R. FREEMAN and E. L. FOUTS

Ice cream manufacturers, like individuals in all other indus-
tries, have been handicapped by shortages of raw materials
since the entrance of this nation into active participation in
World War II. Sugar, vanilla and chocolate were among the
first ice cream ingredients of major importance to be curtailed.
A year later milk solids became scarce, resulting in government
regulations concerning the use of such solids in ice cream. Pre-
vious publications from this laboratory have dealt with the
problem of sweeteners (3, 4)1. This bulletin is a report on
experiments dealing with the problem of manufacturing ice
cream with limited supplies of milk solids.
In 1942 the impending shortage of milk solids became appar-
ent, although the probability of government restrictions on the
use of such solids in ice cream had not yet been intimated.
However, in the latter part of 1942 the situation became acute,
and it was obvious that less milk-solids-not-fat would be avail-
able for use in ice cream. Accordingly, investigations were
begun in December of that year, to search for pure food materials
that could be used for improving the body and texture of ice
cream containing reduced quantities of milk solids.

EXPERIMENTAL PROCEDURES AND RESULTS
I.-PRELIMINARY STUDIES WITH VARIOUS PRODUCTS
Having in mind the factors of availability, cost and probable
suitability for use in ice cream, it was decided that cereal
products should be the subject of preliminary trials. Of the
many cereal products available, it was believed that a number
would be definitely unsuitable for 1 or more reasons. Such fac-
tors as solubility, flavor, color, effect on viscosity and effect on pH
might be involved. To eliminate those substitutes which were
obviously unsatisfactory, preliminary "weeding out" trials were
conducted.
For this purpose small laboratory mixes were prepared. The
method of processing followed closely that used commercially,

1Italic figures in parentheses refer to Literature Cited in the back of
this bulletin.






Florida Agricultural Experiment Station


except that the mixes were not subjected to commercial
homogenization; instead, the mixes were passed through a
small hand-operated homogenizer. Pressures obtained were
not known, but were undoubtedly much lower than would be
obtained in a commercial machine. Vanilla flavoring was added
in the proportion regularly used in vanilla ice cream.
Although no attempt was made to score the mixes numerically,
they were examined for flavor and were' observed for sediment
and color. Comments of the judges concerning these character-
istics were recorded. The products examined, together with
results obtained, are summarized in Table 1.
The corn starch, farina, and wheat flour used in this series
of experiments were standard commercial products obtainable
from any grocery store. The peanut flour, cottonseed flour, and
soyflours were commercially manufactured products obtained
directly from the miller. The peanut proteins were especially
prepared for these trials by the Oil, Fat, and Protein Division
of the Southern Regional Research Laboratory, New Orleans,
Louisiana.
As a result of these observations on small laboratory mixes,
corn starch, farina, and peanut proteins were eliminated from
further study. Although the remaining materials were not con-
sidered ideal, their potentialities appeared to justify further
experimentation. A series of 50-pound mixes then was pre-
pared, using each of the following in a separate mix: general
purpose wheat flour, peanut flour, cottonseed flour, soyflour No.
1, and soyflour No. 3. All mixes contained 10.5% fat, 14%
sugar, 8.4% serum solids, 2% flour, and 0.1% stabilizer (dari-
loid).
The mixes were prepared in 10-gallon milk cans. Dry in-
gredients, except stabilizer and part of the sugar, were added
to the liquid ingredients when the latter reached a temperature
of approximately 120 F. The stabilizer-sugar mixture was
added when the remainder of the mix reached pasteurizing tem-
perature. The mixes were pasteurized at 1600 F. for 30 minutes.
Two-stage homogenization was employed, using 2500 pounds
pressure on the first valve and 1000 pounds on the second. The
mixes were cooled on a surface cooler. All mixes were frozen
in a 40-quart triple dash direct expansion freezer.
The results obtained with these mixes are indicated in Table
2. Scores were not recorded because in the case of all products
except wheat flour the characteristic flavor contributed to the






MILK SOLIDS SUBSTITUTES USED IN EXPERIMENTAL LABORATORY MIXES.


Product


Corn starch .............

Farina ..................

General purpose
wheat flour .........

Peanut flour ........

Cottonseed flour ...

Soyflour No. 1 ......


Soyflour No. 2 .......

Soyflour No. 3 .......


Peanut protein
15G* ....................

Peanut protein
17G* .......-......


Flavor

Starchy, flat

S Clean, flat

Clean, slightly
flat

. Very slight peanut
-not unpleasant

SSimilar to molass-
es-not unpleasant

S Foreign-not
particularly
objectionable

Similar to
Soyflour No. 1

. Similar to Soy-
flour No. 1 but
more pronounced

Pronounced "raw
peanut" flavor

Similar to 15G


Color

Normal

Normal

Normal

Normal

Greenish-
yellow

Normal


Normal

Normal


Normal

Normal


Results
Body and Texture I


Slightly viscous

Viscous

Normal to slightly
viscous

Viscous

Normal

Normal


Normal

Normal


Viscous, slightly
sandy texture

Slightly sandy
texture


Sediment


None

Slight

None

Noticeable

Noticeable

Slight


Slightly more than
Soyflour No. 1

Noticeable


Very Slight

Very Slight


Remarks


Viscosity in proportion
to amount used

Gelatinous "grains"
visible in mix

Viscosity depends on
amount used
















Curdles mix unless acid-
ity partially neutralized


* Obtained from Southern Regional Research Laboratory, New Orleans, La.


I


TABLE 1.-RESULTS WITH


0










I
c-

Iv
"-m








t-
<




o





T


















TABLE 2.-PRELIMINARY TRIALS WITH 50-POUND MIXES.

Body and
Product Employed Flavor of Ice Cream Texture of Ice Color of I
Cream

Wheat flour ............................ Excellent Good Nor

Peanut flour ............................ Typical of product Good Nor

Cottonseed flour...... ............. Typical of product Good Caramel, w
greenish


Soyflour No. 1 ......................

Soyflour No. 3 .....................


Typical of product

Slightly more pronounced
than No. 1


Good

Good


Nor

Nor


ce Cream


mal

mal

ith slightly
sh cast

mal

mal


Whipping Prop-
erties of Mix

Excellent

Excellent

Excellent


Excellent

Excellent







Manufacture of Ice Cream with Limited Milk Solids 9

ice cream by the product was such that it seemed impractical
to attempt to use the standard ice cream score card.
The ice cream containing wheat flour was considered by many
individuals who examined it as being equally as good in flavor as
commercial vanilla ice creams made according to conventional
formulas. The other 4 materials contributed distinct flavors
which, in each case, were characteristic of the particular flour
involved. While none of these flavors was considered to be
definitely unpleasant, it was generally agreed among the ma-
jority of those who tasted the ice creams that such products
would not be suitable to use in vanilla ice cream. Undoubtedly,
some of these flours could be used with success in highly flavored
creams such as chocolate, fruits, toffees, bisques, etc. No such
trials have been included in our studies, since it was felt that
the ice cream manufacturer would be interested primarily in an
ingredient which could be used in all mixes.

II.-OAT FLOUR STUDIES
For several years oat flour has been used in ice cream, pri-
marily as an antioxidant. Also, it has been shown to possess
stabilizing properties. Consequently, it was not considered
necessary to include oat flour in the preliminary trials, for it
was already known that it could be used in small quantities.
However, this product has not been used commonly in ice
cream in excess of 0.5%o of the mix. To ascertain the feasibility
of using larger amounts of oat flour, mixes were prepared con-
taining varying increments of this material. The amounts of
oat flour and stabilizer used are indicated in Table 3. All mixes
contained 10.5% butterfat, 14% sugar, and 8.4% serum solids.
Ingredients used consisted of cream containing 40% fat, con-
densed skimmilk, sugar, flour, dariloid and water. Dry ingredi-
ents were mixed together and added to the liquid ingredients

TABLE 3.-COMPOSITION OF MIXES IN OAT FLOUR SERIES.
Mix Number Flour Stabilizer
percent percent
1 ................... .... ...........I.. 3.0 wheat None
2 .................. .............-.. ...........- 0.5 oat 0.2
3 ..................-. ........ ....... ..... I 1.0 oat 0.1
4 ................ ..... .................. ...... 1.5 oat 0.1
5 .................... ....... .............. ... ... 2.0 oat None
6 ......... ---.................... ....... ..... 2.5 oat None
7 ........... .......................I... ...... 3.0 oat None
I







Florida Agricultural Experiment Station


when the latter had reached pasteurization temperature. The
mixes were pasteurized at 1600 F. for 30 minutes. The only
difficulty encountered in processing these mixes was the in-
ability to obtain complete dispersion of the oat flour. The
amount of sediment remaining in the container at the end of
the pasteurization period was in direct proportion to the amount
of oat flour added at the beginning. Mixes number 4 to 7,
inclusive, were decidedly ropy, but only No. 7 was sufficiently
so to cause difficulty in cooling. Speed of whipping decreased
slightly with increase in oat flour content. It is not known
whether this decrease in whipping was due to the higher oat
flour content or to the decreased amount of stabilizer, or to a
combination of the 2 variables.
,The scores for the ice creams frozen from this series of
mixes are shown in Table 4. The values recorded are based
upon the American Dairy Science Association revised score
card. When more than 1 judge recorded the same criticism,
this fact is indicated by an appropriate number in parentheses
following the criticism. There is little choice among the first
5 ice creams of this series, from the standpoint of flavor or
body and texture. The samples containing 2.5 and 3 % oat flour,
however, were slightly inferior in flavor, as the scores indicate.

III.-PRELIMINARY STUDIES WITH GENERAL PURPOSE
(BLENDED) WHEAT FLOUR
To be suitable for use in commercial ice cream, any material
under consideration should be readily available, reasonable in
cost, have no deleterious effect on the flavor of the finished
product, be beneficial to the body and texture of the ice cream,
and be incorporated easily in the mix by the usual processing
methods. In complying with these specifications wheat flour
appeared to offer the best possibility of the products thus far
investigated. Therefore it seemed advisable to make a more
extensive study of this material so that definite recommenda-
tions could be formulated to serve as a guide for ice cream
manufacturers.
1. Effect of Varying Flour Content at Different Serum Solids
Levels.-It was thought that the extent to which flour might
replace serum solids satisfactorily would depend upon the con-
centration of serum solids prior to substitution. This was studied
by preparing a series of mixes at serum solids levels of 11, 10,







Florida Agricultural Experiment Station


when the latter had reached pasteurization temperature. The
mixes were pasteurized at 1600 F. for 30 minutes. The only
difficulty encountered in processing these mixes was the in-
ability to obtain complete dispersion of the oat flour. The
amount of sediment remaining in the container at the end of
the pasteurization period was in direct proportion to the amount
of oat flour added at the beginning. Mixes number 4 to 7,
inclusive, were decidedly ropy, but only No. 7 was sufficiently
so to cause difficulty in cooling. Speed of whipping decreased
slightly with increase in oat flour content. It is not known
whether this decrease in whipping was due to the higher oat
flour content or to the decreased amount of stabilizer, or to a
combination of the 2 variables.
,The scores for the ice creams frozen from this series of
mixes are shown in Table 4. The values recorded are based
upon the American Dairy Science Association revised score
card. When more than 1 judge recorded the same criticism,
this fact is indicated by an appropriate number in parentheses
following the criticism. There is little choice among the first
5 ice creams of this series, from the standpoint of flavor or
body and texture. The samples containing 2.5 and 3 % oat flour,
however, were slightly inferior in flavor, as the scores indicate.

III.-PRELIMINARY STUDIES WITH GENERAL PURPOSE
(BLENDED) WHEAT FLOUR
To be suitable for use in commercial ice cream, any material
under consideration should be readily available, reasonable in
cost, have no deleterious effect on the flavor of the finished
product, be beneficial to the body and texture of the ice cream,
and be incorporated easily in the mix by the usual processing
methods. In complying with these specifications wheat flour
appeared to offer the best possibility of the products thus far
investigated. Therefore it seemed advisable to make a more
extensive study of this material so that definite recommenda-
tions could be formulated to serve as a guide for ice cream
manufacturers.
1. Effect of Varying Flour Content at Different Serum Solids
Levels.-It was thought that the extent to which flour might
replace serum solids satisfactorily would depend upon the con-
centration of serum solids prior to substitution. This was studied
by preparing a series of mixes at serum solids levels of 11, 10,










TABLE 4.-ICE CREAM SCORES FOR THE OAT FLOUR SERIES.


Flavor
Score* Criticism

39.5 Lacks fine flavor


1
1..........


2..........


3... --





5..........


6...........



7...........


...-....--.-....-------------


.---- --------------


....................


....---------..--------......-..-.


..-.. ...---------------.



...........- ...-..... -


Mix Number


Body and Texture
| Score* Criticism

28.8 Coarse
Slightly coarse

28.5 Coarse


28.2 Coarse
Slightly coarse

28.5 Coarse
Slightly coarse

28.5 Coarse
Slightly coarse (2

28.0 Coarse
Weak
Slightly Coarse

28.0 Slightly coarse
Weak
Coarse


I Melting Qualities
| Score* Criticism

5


5 |
5

5 ......


4.5 Very slightly cu


4.5 Very slightly cu


5 I


melting qualities, 5. These values apply to scores subsequently reported in thi


rd3


cdy


Lacks flavor
Cereal flavor




Lacks fine flavor


Slight off flavor


Slight cereal
Off flavor


Cereal flavor
Cereal flavor


Perfect scores are as follows: Flavor 45; body and texture, 30;
bulletin.


Cs
-5

y

5-.

C_
o














5 3.






Co
*-.
>-
r







Florida Agricultural Experiment Station


and 9%, with flour substitutions of 0, 1, and 2% at each serum
solids level. The serum solids and flour contents of the mixes
of this series are shown in Table 5.

TABLE 5.-COMPOSITION OF MIXES HAVING DIFFERENT SERUM SOLIDS
CONTENTS.
Mix Number I Serum Solids Wheat Flour 1 Total Solids*
percent percent percent
1 ........-......... ..................... 11 0 35.85
2 ..--.......................... ......... 10 1.0 35.73
3 ....... ---..... ...............- ... 9 2.0 35.61
4 -----.........- ..-- ......-.........-- 10 0 34.85
5 ....-...... .....-............ 9 1.0 34.73
6 ....................................... 8 2.0 34.61
7 ........................ ............ 9 0 33.85
8 ........................................ 8 1.0 33.73
9 ..................--.................. -7 2.0 33.61
10** ................................. 8 2.0 34.61

*The wheat flour was assumed to be 88% dry matter (2).
** Processed differently, as described in text.

A base mixture was prepared using cream containing 40%
fat, skimmilk, sugar, and gelatin in such proportions that, upon
the addition of the proper amounts of dry skimmilk and flour,
the processed mixes would have the following composition:
10.5% fat, 14% sugar and 0.35% gelatin. From this base
mixture individual 50-pound mixes were prepared by adding
the dry mixture of powdered skimmilk and wheat flour at a
temperature of approximately 1100 F. The mixes were pas-
teurized at 1500 F. for 30 minutes, and homogenized at 2,500
pounds plus 1,000 pounds.
The composition of No. 10 mix was identical with that of
No. 6 but the method of processing was different. In processing
mix No. 10 the dry skimmilk and flour were added to 11/2 gallons
of the base mix. The resulting mixture was heated to 1720 F.
for 5 minutes, after which it was added to the remainder of
the base mixture and the entire mix was then pasteurized in
the usual manner.
Scores and criticisms of the ice creams frozen from mixes
in this series are given in Table 6. The data indicate a slight
tendency toward a decrease in flavor score as the amount of
substitution is increased. It is questionable, however, that this
trend is noticeable enough to be significant. Substitution of
flour for serum solids apparently had no effect on body and
texture. In this series melting qualities in the ice creams





TABLE 6.-EFFECT OF PARTIALLY SUBSTITUTING WHEAT FLOUR FOR SERUM SOLIDS ON QUALITY OF THE RESULTING ICE CREAM.*


Mix Number Score
______________Score I


1...................... .............

2....... .................... .........

3....... .............. ............


4.................... ................


5.....................................

6...............................-..


7.....................................


8...................... ....... .......

9................... ............ ..


10..........


39.7

39.0

38.7


38.7


39.2

39.0


39.5

39.0


38.8


38.2


Flavor
Criticism

Slight cooked

Slight cooked
Lacks freshness

Cooked
Lacks flavor
Lacks fine flavor

Lacks flavor (2)
Lacks fine flavor
Cooked

Cooked (2)
Slight cooked

Cooked
Lacks flavor
Lacks fine flavor

Cooked

Lacks flavor (2)
Lacks fine flavor

Lacks flavor (3)
Lacks fine flavor
Slight "flour"

Cooked
Lacks flavor (2)
Lacks fine flavor
Slight "flour"


Body and Texture


SScore

29.0

27.5

28.0


28.75


28.75

28.5


28.25

28.25

28.5


28.25


Criticism

Slightly coarse

Coarse (2)
Weak

Slightly weak
Icy

Slightly weak
Slightly coarse

Weak
Icy

Slightly weak
Slightly coarse

Weak
Slightly coarse

Weak
Slightly weak

Icy


Slightly weak
Icy


Score


* For explanation of numbers in parentheses. see discussion in text.


Melting Quality


Criticism


Curdy

Curdy (2)






Slightly curdy


Slightly curdy





Curdy
Whey

Curdy (2)
Whey

Curdy
Slightly curdy


- -------- ----- ----------







Florida Agricultural Experiment Station


seemed to be improved with higher total solids contents. It
also appears that there was a more pronounced tendency toward
curdiness and wheying off in the flour mixes than in those
mixes containing no flour.
2. Wheat Flour as a Stabilizer.-It was observed in process-
ing the mixes thus far reported that their viscosity increased
as the flour content was increased. This suggested that the
amount of stabilizer used should be reduced in mixes containing
flour. The extent to which flour might serve as a stabilizer was
not known, but it was thought that it possessed some stabilizing
properties. To obtain information on this point 4 mixes were
prepared using the following ingredients: cream containing
40% fat, condensed skimmilk, sugar, flour, dariloid and water.
The flour was mixed dry with part of the sugar, this mixture
being added to the liquid ingredients when the latter had reached
a temperature of approximately 1100 F. The stabilizer was
mixed dry with the remaining portion of the sugar, and this
dry mixture was added when the remainder of the mix reached
pasteurization temperature. The mix was pasteurized at 1600
F. for 30 minutes. The mixes were aged approximately 1 hour
before freezing.
Table 7 shows the composition of the mixes in this series and
the scores of the resulting ice creams. All mixes in this series
were satisfactory from the standpoint of viscosity on the cooler
except No. 3, which was slightly too viscous to flow over the
cooler readily. It should be noted that there is no significant
difference in the body and texture or melt-down scores of the
4 ice creams in this series. Sample No. 4, containing 3% flour
and no stabilizer, was fully as satisfactory in every respect as
the other 3 ice creams. Further studies dealing with the stabiliz-
ing properties of flour are reported in a subsequent portion of
this bulletin.
3. Addition of Salt to Flour Mixes.-It was observed early
in the course of the experiments that those mixes which were
low in serum solids and relatively high in wheat flour possessed
a decidedly flat taste. It was also found that this could be over-
come largely by the addition of a small amount of table salt.
Mixes containing not more than 8.5 % serum solids and as much
as 2% wheat flour will be improved by the addition of salt. The
amount used should be just slightly less than that which pro-
duces a definite salty taste in the ice cream. It has been de-
termined through numerous trials that for ice cream contain-







Florida Agricultural Experiment Station


seemed to be improved with higher total solids contents. It
also appears that there was a more pronounced tendency toward
curdiness and wheying off in the flour mixes than in those
mixes containing no flour.
2. Wheat Flour as a Stabilizer.-It was observed in process-
ing the mixes thus far reported that their viscosity increased
as the flour content was increased. This suggested that the
amount of stabilizer used should be reduced in mixes containing
flour. The extent to which flour might serve as a stabilizer was
not known, but it was thought that it possessed some stabilizing
properties. To obtain information on this point 4 mixes were
prepared using the following ingredients: cream containing
40% fat, condensed skimmilk, sugar, flour, dariloid and water.
The flour was mixed dry with part of the sugar, this mixture
being added to the liquid ingredients when the latter had reached
a temperature of approximately 1100 F. The stabilizer was
mixed dry with the remaining portion of the sugar, and this
dry mixture was added when the remainder of the mix reached
pasteurization temperature. The mix was pasteurized at 1600
F. for 30 minutes. The mixes were aged approximately 1 hour
before freezing.
Table 7 shows the composition of the mixes in this series and
the scores of the resulting ice creams. All mixes in this series
were satisfactory from the standpoint of viscosity on the cooler
except No. 3, which was slightly too viscous to flow over the
cooler readily. It should be noted that there is no significant
difference in the body and texture or melt-down scores of the
4 ice creams in this series. Sample No. 4, containing 3% flour
and no stabilizer, was fully as satisfactory in every respect as
the other 3 ice creams. Further studies dealing with the stabiliz-
ing properties of flour are reported in a subsequent portion of
this bulletin.
3. Addition of Salt to Flour Mixes.-It was observed early
in the course of the experiments that those mixes which were
low in serum solids and relatively high in wheat flour possessed
a decidedly flat taste. It was also found that this could be over-
come largely by the addition of a small amount of table salt.
Mixes containing not more than 8.5 % serum solids and as much
as 2% wheat flour will be improved by the addition of salt. The
amount used should be just slightly less than that which pro-
duces a definite salty taste in the ice cream. It has been de-
termined through numerous trials that for ice cream contain-















TABLE 7.-WHEAT FLOUR AS AN ICE CREAM STABILIZER.


Mix Number




1..........................

2..............-.........

3..........................

4........................


Composition*


Flour I Stabilizer


percent

2

2

3


3


percent


Flavor


Score I


39.95

39.75

39.25


39.75


Body and Texture


Criticisms Score Criticisms


Lacks fine flavor

Lacks fine flavor

Slight "floury"

Lacks fine flavor


28.5

28.0

28.5

28.5


Coarse, weak

Coarse, weak

Slightly coarse
Slightly weak

Slightly coarse


1


* All mixes contained 10.5% fat, 14% sugar, and 8.4% serum solids.


Cb
Melting o
Quality
Score

$
5

5
5


5 ci
0-




8
S


--


I


* All mixes contained 10.5% fat, 14% sugar, and 8,4% serum solids.






Florida Agricultural Experiment Station


ing approximately 8.5% serum solids and 2% flour, the addition
of 0.1% salt produced best results. It is extremely essential
that the salt be included, as it materially improves the flavor
of ice cream containing flour.

IV.-STUDIES WITH DIFFERENT GRADES OF WHEAT FLOUR
Through correspondence with the research staff of a large
flour milling organization the authors received the suggestion
that the protein content of the flour might influence its utility
as an ice cream ingredient. To examine this angle of the use
of wheat flour in ice cream, 3 grades of flour were obtained for
experimental purposes, ranging from soft to hard wheat, and
containing approximately 9%, 10.5% and 12% protein.
Three ice cream mixes were prepared, using each of the 3
grades of flour in a separate mix. A fourth mix (control) con-
tained no flour. The flour mixes were of the following composi-
tion: 10% butterfat, 8% serum solids, 14% sugar, 2.5% flour,
and 0.1% salt. The control mix was similar in composition ex-
cept that it contained neither flour nor salt, but did contain
0.35 % gelatin. Milk solids were obtained from cream containing
40% fat, and plain condensed skimmilk containing 36% solids.
In the processing of these mixes all dry ingredients were mixed
together and this dry mixture was added to the liquid ingredients
after the latter had reached a temperature of approximately
110 to 1200 F. Pasteurization was accomplished by holding
the mixes at 1500 F. for 30 minutes. The mixes were homogen-
ized at 2,500 pounds plus 1,000 pounds, and were cooled over a
surface cooler. After aging 24 hours at 350 to 400 F. the mixes
were frozen in a 21/2-gallon counter freezer.
1. Acidity and Viscosity of Mix.-Titratable acidity and rela-
tive viscosity determinations were made on the 4 mixes of this
series. In making the acidity test a 9-gram sample of mix was
used. The sample was diluted with an equal volume of distilled
water before titrating. Five drops of phenolphthalein were
used. Viscosity determinations were made by timing the flow
of the mix from a pipet, and comparing with the time required
for water to flow from the same pipet at the same temperature.
Measurements were made at 750 F. The relative viscosity
values were calculated by the following formula:
Time of flow of mix
Relative viscosity Time of flow of water






Florida Agricultural Experiment Station


ing approximately 8.5% serum solids and 2% flour, the addition
of 0.1% salt produced best results. It is extremely essential
that the salt be included, as it materially improves the flavor
of ice cream containing flour.

IV.-STUDIES WITH DIFFERENT GRADES OF WHEAT FLOUR
Through correspondence with the research staff of a large
flour milling organization the authors received the suggestion
that the protein content of the flour might influence its utility
as an ice cream ingredient. To examine this angle of the use
of wheat flour in ice cream, 3 grades of flour were obtained for
experimental purposes, ranging from soft to hard wheat, and
containing approximately 9%, 10.5% and 12% protein.
Three ice cream mixes were prepared, using each of the 3
grades of flour in a separate mix. A fourth mix (control) con-
tained no flour. The flour mixes were of the following composi-
tion: 10% butterfat, 8% serum solids, 14% sugar, 2.5% flour,
and 0.1% salt. The control mix was similar in composition ex-
cept that it contained neither flour nor salt, but did contain
0.35 % gelatin. Milk solids were obtained from cream containing
40% fat, and plain condensed skimmilk containing 36% solids.
In the processing of these mixes all dry ingredients were mixed
together and this dry mixture was added to the liquid ingredients
after the latter had reached a temperature of approximately
110 to 1200 F. Pasteurization was accomplished by holding
the mixes at 1500 F. for 30 minutes. The mixes were homogen-
ized at 2,500 pounds plus 1,000 pounds, and were cooled over a
surface cooler. After aging 24 hours at 350 to 400 F. the mixes
were frozen in a 21/2-gallon counter freezer.
1. Acidity and Viscosity of Mix.-Titratable acidity and rela-
tive viscosity determinations were made on the 4 mixes of this
series. In making the acidity test a 9-gram sample of mix was
used. The sample was diluted with an equal volume of distilled
water before titrating. Five drops of phenolphthalein were
used. Viscosity determinations were made by timing the flow
of the mix from a pipet, and comparing with the time required
for water to flow from the same pipet at the same temperature.
Measurements were made at 750 F. The relative viscosity
values were calculated by the following formula:
Time of flow of mix
Relative viscosity Time of flow of water







Manufacture of Ice Cream with Limited Milk Solids 17

Acidity and viscosity data are indicated in Table 8. The
slight increase in the titratable acidity of those mixes to which
flour was added apparently was due to the titratable acidity of
the flour. This acidity varies considerably among different
brands of flour. To demonstrate this, a 2.5% solution was pre-
pared from each of 7 brands of wheat flour by heating in a
water bath to 1500 F., which temperature was maintained for
30 minutes. After the solutions were cooled, 100 ml. quantities
of each solution were titrated with N/10 NaOH, using phenolph-
thalein as indicator. The milliliters of tenth normal alkali re-
quired for the 7 flour solutions were 0.73, 0.88, 0.62, 1.81, 0.77,
1.20, and 1.45.
The flour mixes, containing no gelatin, changed very little in
viscosity as they aged, although there was a slight tendency
toward a decrease at the end of 26 hours. The flour mixes were
noticeably more viscous than the control. There seemed to be
no significant differences in viscosity among the 3 flour mixes,
which suggests that the increased viscosity of ice cream mixes
resulting from the addition of flour must have been due to flour
constituents other than protein-probably starch.

TABLE 8.-TITRATABLE ACIDITY AND RELATIVE VISCOSITY OF ICE CREAM
MIXES AS AFFECTED BY WHEAT FLOUR OF DIFFERENT GRADES.

Mix Containing Titratable Relative Viscosity After Aging
Acidity 1 Hour 1 5 Hours I 26 Hours
percent*
No flour .............----............. 0.13 1.25 1.29 1.44
Low-protein flour ........ 0.145 1.97 2.00 1.93
Medium-protein flour -... 0.15 1.82 1.80 1.78
High-protein flour ........ 0.15 2.19 2.21 2.06

Calculated as lactic acid.

2. Whipping Properties of Mix and Melting Resistance of
Ice Cream.-The total time required to reach 100% overrun
with this series of mixes was as follows:
Mix containing no flour, 11.0 minutes
Mix containing low-protein flour, 11.0 minutes
Mix containing medium-protein flour, 10.33 minutes
Mix containing high-protein flour, 10.38 minutes
In each case the whipping time is the average for 2 batches.
These results indicate that flour has very little effect on the
whipping ability of an aged mix.







Florida Agricultural Experiment Station


The chief reason for adding any cereal product to ice cream
low in milk solids is to impart smoothness and give more body
to the finished product. This function is also performed to a
certain degree by stabilizers which, in addition, contribute melt-
ing resistance to the ice cream. In fact, resistance to melting
and desirable body and texture characteristics often are related
directly. Consequently, it was thought that melt-down tests
might supply information that would be of value in supplement-
ing body and texture scores.
For these trials ice cream was hardened in 7-ounce paper cups.
At the time the test was made the ice cream was removed
quickly from the cup and placed on 1/-inch mesh hardware
cloth, which in turn was supported by a glass funnel. The melt-
ing ice cream was collected by the funnel, which emptied into
a graduated cylinder. The room temperature was approximately
84 to 860 F. during all the melting trials herein reported. The
time required for the first drop of melted ice cream to leave
the funnel was observed, and the volume of melted ice cream
was noted after definite time intervals. Each of the values
given in Table 9 is the average of results of 2 trials.

TABLE 9.-EFFECT OF WHEAT FLOUR ON MELTING RESISTANCE OF
ICE CREAM.

Mix Containing Time to Volume of Melted Ice Cream
first drop 30 minutes 1 45 minutes
minutes milliliters milliliters
No flour ...........--.......----------- 4.8 70 92
Low-protein flour .................. 4.6 90 108
Medium-protein flour ......... 4.55 89 106
High-protein flour ............... 5.6 86 104


The total time required for the entire sample of ice cream
to melt completely was not recorded, but was about the same
for all 4 ice creams, the volume differences being due primarily
to differences in the foaminess of the melted ice cream. Judging
from the data in Table 9, it seems that there is little choice
among the 3 grades of flour so far as stabilizing properties are
concerned. Although the volume of melted ice cream was ap-
preciably larger in the flour samples, this was due primarily
to the larger amount of foam in the latter. The time to the
first drop and the total melting time were approximately the
same for the non-flour sample and the average of the 3 flour







Manufacture of Ice Cream with Limited Milk Solids 19

samples. It would seem, therefore, that the flour samples were
about as well stabilized as the sample containing gelatin.
Subsequent to the completion of this particular phase of the
experimental work, many commercial ice cream mixes have been
processed in the Dairy Products Laboratory. Through many
trials in the making and freezing of such mixes it has been
learned that all of the stabilizer may be eliminated from mixes
containing 2% wheat flour, with quite satisfactory results.
Following this repeatedly confirmed observation, the use of
stabilizer was discontinued in the manufacture of ice cream in
the Dairy Products Laboratory. This represents a material
saving in the cost of the mix, inasmuch as the cost of the flour
is about half that of the stabilizer replaced.
3. Relationship of Grade of Wheat Flour Used to Palatability
of Ice Cream.-In Table 6 and 7 data have been given showing
the effect of flour on the flavor and body and texture of ice
cream. Further evidence on this point is presented in Table 10.
All scores in this table are averages of the independent scores
of 2 judges. Although the scores indicate a slight superiority
as the protein content of the flour decreases, the difference
would seem too small to be of significance. The 3 ice creams
containing flour were slightly superior in flavor to the control,
and definitely superior in body and texture.

V.-PROCESSING METHODS FOR WHEAT FLOUR MIXES
Certain ingredients commonly used in ice cream, as well as
some of the recently advertised milk solids substitutes, require
special treatment or methods of handling to incorporate them
satisfactorily in the ice cream mix or to obtain their full effect.
In some instances, even when the manufacturer's directions are
followed, it is impossible to get complete dispersion of the ma-
terial during the pasteurization period. This makes it necessary
to give special attention to the agitation of the mix during
homogenization, particularly if the mix is drawn off and stored in
cans. In some cases it may even cause trouble in homogenizing.
Observations made in the course of conducting numerous ex-
periments and preparing many commercial size mixes, together
with the experience of a number of ice cream manufacturers in
Florida, indicate that few difficulties are encountered in the use
of wheat flour in ice cream. To obtain definite information on
certain phases of the process a series of 5 mixes was prepared,
using a slightly different method for processing each mix in the
series.







Manufacture of Ice Cream with Limited Milk Solids 19

samples. It would seem, therefore, that the flour samples were
about as well stabilized as the sample containing gelatin.
Subsequent to the completion of this particular phase of the
experimental work, many commercial ice cream mixes have been
processed in the Dairy Products Laboratory. Through many
trials in the making and freezing of such mixes it has been
learned that all of the stabilizer may be eliminated from mixes
containing 2% wheat flour, with quite satisfactory results.
Following this repeatedly confirmed observation, the use of
stabilizer was discontinued in the manufacture of ice cream in
the Dairy Products Laboratory. This represents a material
saving in the cost of the mix, inasmuch as the cost of the flour
is about half that of the stabilizer replaced.
3. Relationship of Grade of Wheat Flour Used to Palatability
of Ice Cream.-In Table 6 and 7 data have been given showing
the effect of flour on the flavor and body and texture of ice
cream. Further evidence on this point is presented in Table 10.
All scores in this table are averages of the independent scores
of 2 judges. Although the scores indicate a slight superiority
as the protein content of the flour decreases, the difference
would seem too small to be of significance. The 3 ice creams
containing flour were slightly superior in flavor to the control,
and definitely superior in body and texture.

V.-PROCESSING METHODS FOR WHEAT FLOUR MIXES
Certain ingredients commonly used in ice cream, as well as
some of the recently advertised milk solids substitutes, require
special treatment or methods of handling to incorporate them
satisfactorily in the ice cream mix or to obtain their full effect.
In some instances, even when the manufacturer's directions are
followed, it is impossible to get complete dispersion of the ma-
terial during the pasteurization period. This makes it necessary
to give special attention to the agitation of the mix during
homogenization, particularly if the mix is drawn off and stored in
cans. In some cases it may even cause trouble in homogenizing.
Observations made in the course of conducting numerous ex-
periments and preparing many commercial size mixes, together
with the experience of a number of ice cream manufacturers in
Florida, indicate that few difficulties are encountered in the use
of wheat flour in ice cream. To obtain definite information on
certain phases of the process a series of 5 mixes was prepared,
using a slightly different method for processing each mix in the
series.


















TABLE 10.-EFFECT OF WHEAT FLOUR ON PALATABILITY


Ice Cream Containing Flavor


N o flour ......................... ......... .. .......

Low-protein flour ..................--.....................

Medium-protein flour ............... ...-.... ........

High-protein flour ............... ........... .......


I Score

38.5

39.25

39.0

38.75


Criticisms


Slightly lacking fine flavor
Flat

Lacks fine flavor

Lacks fine flavor

Slightly lacking flavor
Lacks fine flavor
Flat


OF ICE CREAM.

Body and Texture
Score I Criticisms


26.25

27.75

27.50

27.50


Coarse; weak
Very weak; icy

Coarse

Coarse
Weak

Coarse
Weak


I







Manufacture of Ice Cream with Limited Milk Solids 21

1. Method of Adding Flour.-The usual method of adding
the flour consists of mixing it with a portion of the sugar and
sprinkling this dry mixture onto the surface of the liquid in-
gredients as they are being heated in the mixing vat. This
procedure gives excellent results and is to be recommended as
the standard method. It is possible, however, that conditions
occasionally might be such as to necessitate the addition of the
flour alone. To test the feasibility of this procedure, 2 batches
of mix identical in composition with the medium-protein flour
mix of the preceding series were made.
In 1 mix the flour was added when the liquid ingredients at-
tained a temperature of 1100 F., while in the second mix the
flour was not added until the rest of the mix had reached pas-
teurization temperature. In each case the flour was sprinkled
in slowly while the mix was being agitated with a hand agitator
("stirring rod"). Both mixes were pasteurized at 1500 F. for
30 minutes, homogenized at 2,500 pounds plus 1,000 pounds, and
cooled over a surface cooler.
Relative viscosities of these 2 mixes at different ages are
given in Table 11. This again shows the decrease in viscosity
as the mix ages. The mix was noticeably more viscous when
the flour was added at the pasteurizing temperature. Although
a small amount of flour remained undissolved at the end of the
pasteurization period in both mixes, this characteristic was
more apparent in the mix to which the flour was added at the
lower temperature. Evidently the more complete solution and
greater viscosity are related phenomena. This behavior may
be due to the fact that when flour alone is added to a relatively
cool mix it tends to form small lumps or balls of doughy material
which are never completely penetrated by the liquid, even by
the end of the pasteurization period. This is similar to the dif-
ficulty encountered with milk powder when improper methods
are used.

TABLE 11.-EFFECT OF TEMPERATURE OF ADDING FLOUR ON VISCOSITY
OF Mix.

Mix Temperature Relative Viscosity After
When Flour Added 2 Hours I 6 Hours | 24 Hours
110" F. ........................ .........I 2.30 2.18 2.12
1500 F. ..................................... 3.83 3.41 2.99
II







Florida Agricultural Experiment Station


The mix to which the flour was added at the lower tempera-
ture possessed somewhat better whipping properties, reaching
100% overrun in the freezer in 10.75 minutes, whereas the other
mix required 12 minutes to reach 100% overrun.
Results of the melting tests on the ice cream frozen from
these 2 mixes are shown in Table 12. In this table the total
melting time is given, as well as the time when the first drop
of melted ice cream appeared. These values indicate that slightly
greater stabilizing power is achieved when the flour is added at
the higher temperature. However, the ice cream scores in
Table 13 show no significant difference in the quality of the 2
ice creams.
TABLE 12.-EFFECT OF TEMPERATURE OF ADDING FLOUR ON MELTING
RESISTANCE OF THE ICE CREAM.


Mix Temper- Time to
ature When
Flour Added First Drop
Minutes seconds
110 F. ...... .... 5 40
150 F. ...... .. 8 45


SVolume of Melted Ice Cream
Melt I 15 30 45
Entirely IMinutes Minutes Minutes


minutes
60
61


cc
74
76


TABLE 13.-EFFECT OF TEMPERATURE OF ADDING FLOUR ON QUALITY OF
THE ICE CREAM.


Mix Temperature
When Flour Added


Flavor Body and Texture


Score I Criticism


Score I Criticism


110 F. ................. 39.75 .....
150 F. .................. 39.75 ............


27.5 Coarse; weak
28.0 Slight coarse


Judging from the results obtained on these 2 mixes, it ap-
pears that the temperature at which the flour is added has no
practical effect on the ease of processing nor on the quality of
the finished product. It may also be said that it is possible to
add the flour alone, without previous mixing with part of the
sugar. When this is done it is necessary to sift in the flour
very slowly while the mix is being agitated vigorously.
2. Pasteurization Temperature.-It is known that the vis-
cosity of a flour-in-water suspension increases as the tempera-
ture of the mixture is raised, due to the gelatinization of the
starch granules. From this it would be suspected that the pas-







Manufacture of Ice Cream with Limited Milk Solids 23

teurization temperature employed would influence the physical
properties of the mix and of the finished ice cream.
Three mixes were prepared to study the effect of pasteuriza-
tion temperature. The composition of the mixes was identical
with that of the 2 preceding mixes. Flour and sugar were
mixed dry and added to the liquid ingredients when the latter
had reached a temperature of approximately 1100 F. Pasteuri-
zation temperatures employed were 1450 and 1600 F. for 30
minutes, and 1750 F. for 15 minutes. Each mix was homogenized
at the pasteurization temperature, using 2,500 pounds plus 1,000
pounds. The mixes were cooled on a surface cooler.
Results of the viscosity measurements on these mixes are
presented in Table 14. Here again it may be seen that viscosity
decreases as the mix ages, a phenomenon which, though perhaps
of little significance, is unusual. No explanation for this be-
havior is offered at the present time. There is also a very great
increase in viscosity as the pasteurization temperature is raised
from 145 to 1600 F., and a significant, though smaller, increase
as the temperature was further raised to 1750 F. The decrease
in viscosity of the mix during the first 24 hours of storage
was more pronounced in the mixes with high initial viscosity.

TABLE 14.-EFFECT OF PASTEURIZATION TEMPERATURE ON VISCOSITY OF
MIXES CONTAINING FLOUR.


Pasteurization Temperature


Relative Viscosity
2 Hours 1 6 Hours 1 24 Hours


145 F. ..........- ......... ....... 1.83 1.81 1.82
160 F .... -......... ........ 6.16 I 5.45 4.63
1750 F. ..... ...... ........ ............ 8.57 7.91 6.82

The influence of pasteurization temperature on whipping
properties of flour-containing mixes also is significant. The
mixes pasteurized at 1450, 1600 and 1750 F. required 11.25, 14,
and 16 minutes, respectively, to reach 100% overrun. The ice
cream frozen from the mix pasteurized at 175 F. was quite soft
at the end of the 16-minute period, and had to be refrozen be-
fore it was in suitable condition for drawing. The reduced
whipping ability of the mixes pasteurized at the higher tempera-
tures may be a direct result of the high viscosities of the mixes,
or it may be due to less evident changes in the mix resulting
from the higher temperature treatment.







Florida Agricultural Experiment Station


The relationship of mix pasteurization temperature to the
melting characteristics of the ice cream may be seen by examin-
ing the data in Table 15. In comparing the 2 extreme pasteuri-
zation temperatures it will be observed that the higher tempera-
ture slightly decreased the total melting time but increased the
volume of melted ice cream. The latter condition was due to
the large amount of foam present.
TABLE 15.-EFFECT OF PASTEURIZATION TEMPERATURE ON MELTING
RESISTANCE OF ICE CREAM CONTAINING FLOUR.

Pasteuri- Time to Volume of
zation _Melted Ice Cream
Tempera- I 15 I 30 45
ture First Drop Melt Entirely Minutes I Minutes Minutes
I minutes seconds minutes seconds cc cc cc
145 F. ....... 12 8 62 25 10 88 140
1600 F. ........ 10 25 61 30 6 57 96
1750 F. ...... 11 60 8 72 110


That the temperature at which the mix is pasteurized in-
fluences the "eating" quality of the ice cream is evidenced by
the scores given in Table 16. Although the flavor scores show
no significant differences, the body and texture scores definitely
indicate that 145 F. for 30 minutes is insufficient heat treat-
ment for mixes containing flour. The data in this table also
suggest that there is no advantage in heating above 160 F.

TABLE 16.-EFFECT OF MIX PASTEURIZATION TEMPERATURE ON THE QUALITY
OF ICE CREAM CONTAINING FLOUR.
Pasteuriza-
tion Flavor Body and Texture
Temperature Score | Criticism I Score I Criticism
145 F. ....-....-.. 39.5 Slight "floury" 27.0 Coarse; weak
160 F. ........... 39.75 ............................ 28.25 Slight coarse
1750 F. ......... 39.5 Lacks fine flavor 28.0 Slight coarse; coarse


VI.-THE TESTING OF MIXES CONTAINING FLOUR
It has been reported by 1 plant in Florida that some difficulty
was experienced in applying the Mojonnier fat test to ice cream
mixes containing wheat flour. This point has been checked
carefully at the Dairy Products Laboratory. The results are







Manufacture of Ice Cream with Limited Milk Solids 25

given here, in the event that this question might arise in other
ice cream plants.
Two experimental mixes, A and B, were prepared. They were
calculated to be identical in composition except that A contained
neither flour nor salt, whereas B contained 2% flour and 0.1%
salt. All ingredients were weighed very carefully and pre-
cautions were taken to avoid any losses during processing. Each
mix was tested in quadruplicate by the Mojonnier method, and
in duplicate by the Pennsylvania (6) and Minnesota (1) methods.
Results are shown in Table 17. It will be noted that there is
close agreement among the 4 values for the Mojonnier test on
flour-containing ice cream mix, as well as in a check test between
a mix with flour and one without flour.

TABLE 17.-EFFECT OF WHEAT FLOUR ON ACCURACY OF FAT TESTS OF
ICE CREAM MIx.

Method of Butterfat
Analysis Mix A ( Mix B I Mix C Mix D I Mix E
Percent percent percent percent percent
Mojonnier (a) .. 11.06 11.04 11.23 11.18 11.06
(b) 11.03 11.01 11.16 11.22 11.13
(c) 11.06 11.02 11.14 11.18 11.14
(d) 11.06 11.01 11.17 ...... 11.14
Ave. 11.05 11.02 11.175 11.19 11.12
Pennsyl- (a) 10.8 10.8 11.0 11.4 11.2
vania (b) 10.8 10.9 11.2 11.4 11.3
Ave. 10.8 10.85 11.1 11.4 11.25
Minnesota (a) 11.0 11.2 11.3 11.3 11.4
(b) 11.0 10.9 11.2 11.4 11.4
Ave. 11.0 11.05 11.25 11.35 11.4

To substantiate and extend the results obtained with mixes
A and B, 3 more mixes were carefully prepared and tested as
before. Mix C contained no flour; mix D, 1.5% flour; and mix
E, 3% flour. The results secured on these mixes will be found
in the second section of Table 17. These data indicate again
that wheat flour in quantities up to 3% of the weight of the
mix have no significant effect on the reliability of the Mojonnier
analysis. Although the figures in Table 17 suggest that when
the Pennsylvania and Minnesota methods are used slightly
higher results are obtained if the ice cream mix contains wheat
flour, the trend is of insufficient magnitude to be considered
significant.







Florida Agricultural Experiment Station


It should be mentioned at this point that no manipulative
difficulty was encountered when applying either of the 3 methods
to any of the samples herein reported. It was observed that
after pouring off the ether-fat mixture from the Mojonnier
extraction flask a noticeable amount of flaky material was left
adhering to the walls of the flasks containing wheat flour. This
caused no difficulty in the extraction process, however, and ap-
parently had no effect on the results.

VII.-FLOUR IN SHERBETS
A rather large number of experimental sherbet mixes have
been frozen to study the possible value of wheat flour in sher-
bets. Different quantities of flour have been tried, using sher-
bet mixes made according to various formulas and processed in
different ways. No difficulty was encountered in processing or
freezing sherbet mixes containing wheat flour. Unexpectedly,
however, the flour contributed little if any toward improving
the body and texture of the finished product. On the basis of
these experiments it is not recommended that flour be used in
sherbets, since no appreciable benefit is derived.

GENERAL DISCUSSION

Results of controlled experiments and experience of many
commercial ice cream manufacturers over a period of more than
a year point to the fact that wheat flour is well adapted to use
as an ingredient of wartime ice cream. Some prejudice against
its use has been evident, and is to be expected. In the early
history of the ice cream industry fillers, largely starchy materials,
and ice cream "improvers" were used to excess. Their function
apparently was chiefly to cheapen the ice cream. Fortunately,
the enlightened ice cream manufacturer nowadays selects and
blends his ingredients with several things in mind, such as cost,
availability, and effect on quality of the finished product. Mod-
ern stream-lined competition forces him to give each of these
factors due consideration.
In certain localities the use of wheat flour or other cereal
products in ice cream may be impossible because of legal restric-
tions. Some officials charged with the responsibility of enforc-
ing food processing laws have authorized emergency measures
allowing the incorporation of cereal products in ice cream. In
such cases it is usually specified that the legal standard re-







Florida Agricultural Experiment Station


It should be mentioned at this point that no manipulative
difficulty was encountered when applying either of the 3 methods
to any of the samples herein reported. It was observed that
after pouring off the ether-fat mixture from the Mojonnier
extraction flask a noticeable amount of flaky material was left
adhering to the walls of the flasks containing wheat flour. This
caused no difficulty in the extraction process, however, and ap-
parently had no effect on the results.

VII.-FLOUR IN SHERBETS
A rather large number of experimental sherbet mixes have
been frozen to study the possible value of wheat flour in sher-
bets. Different quantities of flour have been tried, using sher-
bet mixes made according to various formulas and processed in
different ways. No difficulty was encountered in processing or
freezing sherbet mixes containing wheat flour. Unexpectedly,
however, the flour contributed little if any toward improving
the body and texture of the finished product. On the basis of
these experiments it is not recommended that flour be used in
sherbets, since no appreciable benefit is derived.

GENERAL DISCUSSION

Results of controlled experiments and experience of many
commercial ice cream manufacturers over a period of more than
a year point to the fact that wheat flour is well adapted to use
as an ingredient of wartime ice cream. Some prejudice against
its use has been evident, and is to be expected. In the early
history of the ice cream industry fillers, largely starchy materials,
and ice cream "improvers" were used to excess. Their function
apparently was chiefly to cheapen the ice cream. Fortunately,
the enlightened ice cream manufacturer nowadays selects and
blends his ingredients with several things in mind, such as cost,
availability, and effect on quality of the finished product. Mod-
ern stream-lined competition forces him to give each of these
factors due consideration.
In certain localities the use of wheat flour or other cereal
products in ice cream may be impossible because of legal restric-
tions. Some officials charged with the responsibility of enforc-
ing food processing laws have authorized emergency measures
allowing the incorporation of cereal products in ice cream. In
such cases it is usually specified that the legal standard re-






Manufacture of Ice Cream with Limited Milk Solids 27

garding minimum milk-fat and milk-solids-not-fat in ice cream
are to remain unaltered.
Many persons have raised the question of the digestibility of
uncooked flour. As a matter of fact, the flour in ice cream is
not entirely uncooked, for it has been subjected to sufficient
heat to bring about gelatinization of the starch. However, the
following information reported by Langworthy and Deuel (5)
is interesting in this connection.
To determine the digestibility of raw wheat starch, experi-
ments were conducted with 4 normal adults. The starch was
consumed in the form of a frozen pudding, which was prepared
by mixing the ingredients without heating and then freezing
as one would freeze ice cream. The pudding served as part of
a simple mixed diet. The amount of pudding consumed was
such as to furnish an average of about 6.7 ounces of raw starch
per person per day for 3 consecutive days. Values for the di-
gestibility of the raw starch were 99.8%, 98.6%, 98.4%, and
100%, averaging 99.2% for the 4 individuals. These investi-
gators concluded from their studies that the raw wheat starch
was completely assimilated, that it caused no unpleasant physio-
logical disturbances, and that the digestibility of the other con-
stituents of the diet was not affected to any great extent by
the large amounts of raw starch ingested.
This would seem to remove any doubts concerning the di-
gestibility of ice cream which contains flour, since a large indi-
vidual serving of such ice cream contains less than 1/10 ounce
of wheat starch.
One of the practical advantages to the use of wheat flour is
its availability and economy. This question might be raised:
Can the ice cream manufacturer expect uniform results with
different flours? It is not likely that general purpose (blended)
wheat flours will vary in composition a great deal. Any varia-
tion probably would be well within the extremes represented
by the 3 grades of flour used in this study. Since it has been
shown that there is no significant difference in the practical re-
sults obtained with soft, medium and hard wheat flour, it seems
that there need be little concern regarding any lack of uniformity
among flours. Thus the advantage of availability is further
strengthened.
A precaution which should be mentioned in connection with
the use of wheat flour in ice cream has to do with possible in-
festations by weevils or other insects. Flour which has been







Florida Agricultural Experiment Station


in storage long enough to become weevily will very likely have
developed a stale flavor. The presence of either the stale flavor
or the weevils makes the flour undesirable for use in ice cream.
The ice cream maker should refuse to accept delivery of flour
which contains insect larvae, as it is impractical to remove them.
Careful inspection of flour when purchased, and its utilization
within a reasonably short period, will obviate any difficulties
of this nature.
Many plants in the state of Florida are using flour to improve
the quality of their wartime ice creams. All plants contacted
have reported that the addition of flour in the recommended
amount resulted in a noticeably better ice cream. As yet no
reports have been received indicating difficulty resulting from
the use of flour, when recommended procedures were followed
strictly. Approval on an emergency basis has been granted for
the state of Florida by the State Chemist, and by the Chief Dairy
Supervisor, provided that ice cream shall continue to conform
to the legal requirements regarding minimum percentages of
milk-fat and milk-solids-not-fat.
As soon as dairy products are available again in the amounts
required, the use of all substitute materials in ice cream should
be discontinued. Manufacturers should then resume the use
of pre-war formulas containing the usual amounts of milk solids.

PRACTICAL RECOMMENDATIONS

The following recommendations are offered to plants in Flor-
ida manufacturing ice cream, as a practical summary of the
experimental work herein reported.
1. The following composition will be found satisfactory for
most conditions:
Butterfat ......--------. -------....----.-- ..-- 10.5%
Serum solids ..............----------------- 8.4%
Sugar (cane sugar basis) ..-..--------..... .14.0%
Flour .......--------..-.....------.. 2 to 2.5%
Salt ................------------------ 0.1%
2. In processing the mix, the flour should be mixed dry with
2 or 3 times its weight of sugar. This dry mixture is then
sprinkled on the surface of the liquid ingredients when the
latter reach a temperature of 1000 to 130 F.






Manufacture of Ice Cream with Limited Milk Solids 29

3. Pasteurize the mix by holding at 1550 to 1600 F. for 30
minutes.
4. Homogenize at pasteurization temperature, using 2,000
to 2,500 pounds pressure on the first valve, and 750 to 1,000
pounds on the second valve. If a single stage homogenizer is
used, set the pressure at 2,500 to 3,500 pounds.
5. The mixes are cooled, aged and frozen in the usual manner.
6. The flavor of vanilla ice cream containing flour will be
improved by using 15% to 20% more vanilla extract than would
be used ordinarily.

CONCLUSIONS
1. Corn starch, cottonseed flour, soyflour, peanut flour and
peanut proteins are unsuitable for use in commercial ice cream
because of undesirable flavor effects. Farina is impractical be-
cause of its effect on the physical properties of the mix.

2. Oat flour may be used to the extent of 2% in ice cream
without producing a noticeably adverse effect on flavor.
3. Oat flour is not completely dispersed during the process-
ing of ice cream mix. The quantity of sediment remaining in the
processed mix is roughly proportional to the amount of oat
flour used.

4. The body and texture of ice cream low in milk solids is
improved by the addition of oat flour.
5. Of the various cereal products studied, general purpose
(blended) wheat flour has been found most satisfactory in ice
cream when the comparison is based upon availability, cost,
effect on flavor and on body and texture, and ease of dispersion
in the ice cream mix.

6. The ice creams containing 9% serum solids plus 2% flour,
8% serum solids plus 2% flour, and 7% serum solids plus 2%
flour compare favorably in body and texture with ice creams
containing, 11, 10 and 9% serum solids, respectively.
7. When 2% to 2.5% flour is used in ice cream containing
approximately 10.5%o fat, 14% sugar and 8.5% serum solids, a
stabilizer is not needed.







Florida Agricultural Experiment Station


8. It is necessary to add 0.1% table salt to mixes containing
less than 10 % serum solids and as much as 2% wheat flour.

9. Soft, medium, or hard wheat flour may be used in ice
cream with equal success so far as practical results are con-
cerned.

10. To incorporate the wheat flour in the ice cream mix it
should be mixed dry with 2 or 3 times its weight of sugar, and
this dry mixture should be sprinkled into the liquid ingredients
when the latter are at a temperature of 1000 to 1300 F. If this
procedure is followed the flour will be dispersed completely and
permanently during the subsequent pasteurization period.

11. Wheat flour mixes should be pasteurized at a temperature
of 1550 to 1600 F. for 30 minutes.

12. The presence of wheat flour in ice cream mix creates no
particular difficulty in using the Mojonnier or modified Babcock
fat tests on such mixes.

LITERATURE CITED

1. BROWN, W. CARSON, and L. M. THURSTON. The Minnesota method ap-
plied to concentrated milk, chocolate milk and ice cream. Jour. Milk
Technol. 6: 136-141. 1943.
2. CHATFIELD, C., and G. ADAMS. Proximate composition of American food
materials. U. S. Dept. Agr. Circ. 549. 1940.
3. FoUTs, E. L. Sweetening ice cream with honey. Fla. Agr. Exp. Sta.
Press Bul. 582. 1943.
4. FOUTS, E. L., L. E. MULL and T. R. FREEMAN. The preparation and use
of invert sirup in the manufacture of ice cream. Fla. Agr. Exp.
Sta. (Tech.) Bul. 393. 1943.
5. LANGWORTHY, C. F., and H. J. DEUEL, JR. Digestibility of raw corn,
potato, and wheat starches. Jour. Biol. Chem. 42: 27-40. 1920.
6. SWOPE, W. D. The Pennsylvania method for determining the percentage
of fat in dairy products. Pa. Agr. Exp. Sta. Bul. 412. 1941.




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