Dairy Industry, 1949

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					Dairy Industry, 1949
          progress report of research conducted by members of the
          staff of the Division of Dairy Industry at Davis
  The following report was prepared by the staff members of the Division of Dairy Industry under the direction of Professor E. L. Jack, Chairman of
the Division of Dairy Industry and Dairy Technologist in the Experiment Station, Davis.

Bread containing milk is superior to             ing angle, whereas those of poor baking                  Cottage cheese of excellent quality can
bread without milk.                              quality will have a small weakening angle.            be made by these procedures. The addi-
   An experiment was conducted wherein              The same instrument is being used to               tion of non-fat milk solids to liquid skim
a group of 320 boys between the ages of          test the dater absorption property of                 milk can be used as a method of increas-
eight and 16 were fed breads containing          non-fat dry milk solids when used in                  ing plant capacity, of centralizing cottage
different amounts of non-fat dry milk            bread dough. In this test a dough contain-            cheese manufacture in one plant by con-
solids. The non-fat dry milk solids were         ing 50% non-fat dry milk solids is used               densing the skim in others and transport-
incorporated in the standard bread in the        and the absorption value is measured by               ing the condensed skim economically,
following amounts: O%, 6%, 10% and               the dough strength.                                   and of increasing the food value of the
14% of the quantity of flour. Each of                                                                  cottage cheese along with securing in-
these breads was fed during an eight-week                                                              creased yields.
period, after which time the experiment          Cottage Cheese
was repeated with a different order of             The addition of milk solids to skim milk
feeding the breads.                              for the manufacture of cottage cheese im-             Evaporated Milk
   The diets were liberal in all respects        proves the nutritive value of the cottage                Evaporated milk with improved flavor
for which analyses could be made. The            cheese and increases the yield.                       and color can be produced if the oxygen
daily caloric intake was approximately             Experiments were conducted in which                 is removed from the milk before steriliza-
2,900 calories, and the daily protein in-        non-fat milk solids both in the form of               tion, and if the sterilization is of the high
take exceeded 110 grams. The calcium             low-heat dry milk solids and low-heat con-            temperature short-time variety. These
and phosphorus leavels were at or above          densed skim were added to liquid skim                 facts have been determined by examina-
the recommended amounts.                         milk to increase the solids content to                tion of variously processed milks imme-
   The daily food consumption ranged             12%, 15% and 18%. The following                       diately upon processing. Commercial
from 2,200 to 2,400 grams of which the           shows the recovery of solids in the cheese            adoption of these processes is retarded
bread made up 200 to 259 grams.                  and the percentage in the curd.                       by the reversion of flavor and the appear-
   In both trials the bread consumption                                                                ance of gelation and fat separation on
                                                      Solids                                Solids
increased as the amount of milk in the               in milk          Recovered
                                                                                          in cheese    storage. Studies are under way to deter-
bread was increased. The following is                                                                  mine the fundamental causes of these
                                                      9yo             32%                 21.5%        defect developments.
the average percentage of consumption              (no solids
for the two trials:                                 added)
  Percentage non-fat dry milk solids in bread        12%              34%                 23.0%
                                                                                                       Ice Cream Shrinkage
                                                     15%              35%                 24.5%
    0Yo         6Yo        10%           14%                                                              The tendency of certain ice creams to
                                                     18%              37.5%               2 7.2 5 Yo
          Percentage bread consumption                                                                 lose volume on storage or transportation
 100%       104.4%      107.1%      112.6%                                                             is called shrinkage and has been desig-
                                                    It is necessary to make some changes               nated the most important unsolved tech-
  A Micro-Mixograph test was devel-              in the processing procedures to obtain                nical problem in the ice cream industry
oped to determine the baking quality of          best results when adding non-fat milk                 today. Experiments have contributed in
non-fat dry milk solids when used in             solids.                                               two ways to possible means of combating
bread. Bakers are inclined to reduce the           The following table shows the recom-                this defect.
amount of non-fat dry milk solids used           mended processing procedures:                            The structural strength of ice cream as
in their bread unless they can be sure the                                                             indicative of the resistance of the air cell
milk solids possess high baking quality
and will not reduce the volume of the loaf.
                                                  p : ~ l ~ ~ ~ t Rennet
                                                  in milk
                                                                per 1000
                                                               br. milk
                                                                              Per cent
                                                                                                       wall to rupture has been determined. An
                                                                                                       ice cream of standard composition was
Each batch of non-fat dry milk solids             (no solids
                                                                                                       subjected to progressively lower pres-
should be tested by some reliable method           added)                                              sures at constant temperatures, and a
before it is offered to the baker.                  9yo           1.oo             4 yo         6      similar ice cream to progressively lower
   In the Micro-Mixograph test a dough             (non-fat
                                                   dry milk
                                                                                                       temperatures at constant pressures. The
containing 6% non-fat dry milk solids is             solids                                            pressure and temperature at which the
made in the Micro-Mixer. A recording                                                                   structure became weakened and broke
                                                   12%            1.oo             4 yo         6%
device shows the strength of the dough                                                                 were determined.
as indicated by the height on the chart            15%             .75             7%           6         Other studies have pointed the way to
and the resistance of the dough to break-          18%             .75            12%           6      increasing the resistance of the cell wall
down under continuous mixing. This               (condensed
                                                  skim milk
                                                                                                       to fracture. It has been shown that the
breakdown shows up as a receding slope             added)                                              state of the milk proteins is a limiting
on the chart, the measurement of which             12%           1.90             5 %%       5-5%      factor in the cell wall strength. Incipient
is called the weakening angle. Doughs              15%           2.10             5 ?h
                                                                                     o'         6      breakdown in the protein structure as
containing non-fat dry milk solids of good         18%           3.00             6Yo           6      measured by the tyrosine value is suffi-
baking quality will have a large weaken-                                                                          Continued on next page

C A L I F O R N I A A G R I C U L T U R E , MAY, 1950                                                                                             3
Fruit Size and leaf Composition
         concentration of potassium in orange leaves
         found to be associated with fruit 'sizes
                                                                                                                    E R. Parker and Winston W. Jones
Evidence of the effect of potassium-           of the December, 1948, leaf samples. In                                    fruit of relatively large size. The leaves
supplying fertilizers on citrus fruit size     the crops of the individual years, maxi-                                   of the trees which received this fertilizcr
in the long-term experimental orchard at       mum fruit size occurred at leaf concen-                                    contained 1.22% of potassium. About
Riverside was obtained by determining          trations which differed somewhat from                                      three pounds of potash per tree were ap-
the concentrations of this and other ele-      this figure.                                                               plied each year in the manure. Supple-
ments in the leaves.                              Large increases in the potassium con-                                   menting this treatment with applications
   The concentrations were studied in          tent of the leaves resulted from the ap-                                   of sulfate of potash fertilizer did not in-
relation to the sizes of the fruit harvested   plication of bulky organic materials. For                                  crease the size of the fruit, although the
in 1946 to 1949.                               example, a treatment which annually re-                                    extra potash considerably increased the
   A group of 30 fertilizer treatments was     ceived 1.5 pounds of nitrogen per tree                                     potassium in the leaves.
used for this study. A number of the           from dairy or feed-lot manure produced                                        The potassium in the December leaf
treatments received applications of ma-                   A
                                                                                                                          samples ranged from 0.75% to 1.59% of
nure or other bulky organic materials.                                I   I       I       I   I       I   I    I    I     their dry weights. All of the values are
Others differed in respect to the use of       W
                                                    TO                                                                    greater than those which have been re-
covercrops, phosphate or potash fertiliz-      j                                                                          ported by several investigators to be suf-
                                                                                                                          ficient to prevent yield reductions and
ers, agricultural minerals, sources and
 amounts of nitrogen.                               60-                                                                   visible deficiency symptoms.
    Composite samples of spring-cycle          r
                                                                                                                             Other factors than potassium supply
leaves were harvested in December, 1948,       " SO-                                                                      also influence fruit sizes. In these experi-
                                               E                                                                          ments, this is shown by the fluctuations
 for the analyses. The size of the fruits      z
 was highly correlated with the concen-        Y
                                                                                                                          from year to year in the size of the fruit
                                               8 40-
 tration of potassium in the dry weights                                                                                  from trees which have been consistently
 of the leaves.                                0                                                                          fertilized with the same materials. In any
    The relation of fruit size to potassium    5    SO-                                                                   one year differences in fruit size also oc-
 concentration was not at first clear. The
                                                                                                                          curred when trees were fertilized with the
 sizes tended to be larger also when phos-                                                                                same quantity of potassium.
 phorus was more abundant but smaller                                                                                        Inadequate availability of irrigation
 when nitrogen or calcium was high. The                                                                                    water is also one factor which reduces
 concentration of each element was found                                                                                   the size of oranges. Orchard management
 to be affected by the concentrations of                                                                                   practices which affect the penetration of
 the others but the concentrations of po-                                                                                  water into the soil may therefore affect
                                                              A   1   1       1       I   I       I   I   I     I   I
 tassium were the only ones which were                                                                                     fruit sizes.
 firmly associated with the fruit sizes.                                                                                    E. R . Parker is Horticulturist in the Experi-
    The increases in fruit size due to                                                                                    ment Station, Riverside.
 greater potassium absorption were lim-                                                                                      Winston W . Jones is Associate Horticulturist
 ited. Maximum fruit sizes in the 1946-                                                                                   in the Experiment Station, Riverside.
  1949 crops occurred when the potassium                                                                                     The above progress report is based on Re-
 content was about 1.3% in the dry weight                                                                                 search Project No. 594.

                 DAIRY                         that milk pasteurized by the holding                                        The findings of the last few months in-
                                               method shall not be heated above 145" F.                                    dicate that bacteriophage is of greater
        Continued from preceding page                                                                                      importance in California than has previ-
                                               In order not to exceed this temperature
 cient change to weaken the cell walls and     it has been found that the milk should                                      ously been suspected in causing slow cul-
 results in shrinkage under the right con-     not enter the homogenizer warmer than                                       ture development in dairy products. In
 ditions. The heat denaturation of the         137" F if this temperature of 145" F is                                     nine cases of slow acid production during
 whey proteins and particularly of the         not to be exceeded, using a homogeniz-                                      the past winter, bacteriophage was found
 globulin fraction is another underlying       ing pressure of 2,000 lbs. per square inch.                                 to be the cause in each one. Studies of
 factor in shrinkage. Addition to a stand-     If higher pressures are used, lower tem-                                    bacteria-bacteriophage relationships and
 ard mix of less than 0.05% of unde-           peratures must be employed.                                                 of bacteriophage control are under way.
 natured globulin markedly reduced the
 tendency to shrinkage.                            Bacteriophage Studies                                                   Quaternary Ammonium
                                                      Dairy plant operators in California                                     The action of quaternary ammonium
 Homogenized Milk                                  suffer from considerable loss at certain                                compounds on bacteria is sometimes con-
    The temperature of milk increases as           times because of the failure of bacterial                               sidered temporary in effect and possible
 it is passed through a homogenizer. The           cultures to coagulate milk satisfactorily                               of reversal allowing organisms to grow
 Agricultural Code of California specifies         for use in making several dairy products.                                           Continued on page 16

 4                                                                                                            C A L I F O R N I A A G R I C U L T U R E , MAY, 1950
                DAIRY                         content-which is about the average for
                                              the state-will have 7.62 + (0.31 x 3.8),
           Continued from page 4
                                              equals 8.80% solids-not-fat.
again. Since over three million pounds of       Some of the studies reported here were sup-
                                                                                                                             NEW PU                                                            PIS
these agents are now used annually i n        ported in part by funds from the California
sanitizing procedures, it is important to     Dairy Industry Advisory Board. The study on                                      Single copies of these publications or a cata-
test whether or not they are bacterioci-      Milk-Solids-Not-Fat was supported in part by                                   logue of Agricultural Publications may be ob-
dal-will kill the bacteria-or merely bac-     funds from the California Department of Agri-                                  tained without charge from the local ofice of
                                              culture, Bureau of Milk Control. The study on                                  the Farm Advisor or by addressing a request to:
teriostatic-preventing increase.              Dry Milk in Bread was made possible by the                                     Publications Ofice, 22 Giannini Hall, Uni-
   Quaternary compounds, I-alkyl-di-          cooperation of the California Youth Authority.                                 versity of California, College of Agriculture,
methyl-benzyl ammonium chloride-and                                                                                          Berkeley 4, Californie.
11-N-pyridinium chloride-were used on                                                                                        CALIFORNIA RICE PRODUCTION, by
the test organisms Escherichia coli and                         CATERPILLAR                                                  Loren Davis, Ext. Cir. 163 April 1950.
Micrococcus pyogenes var. Aureus. After                        Continued from page 8                                         General discussion of subject amply illus-
use of the quaternary a neutralizing                                                                                         trated and featuring 16 full-page pictures
agent, Congo Red, was applied to attempt      plication of a chemical insecticide. The                                       o worst weeds found in California rice
to reverse the action of the quaternary.      cost of material plus application cost by                                      fields.
Both quaternaries were found to be more       airplane in a virus treatment should be
active against the Micrococcus, a gram        less than that of most chemical insecti-
positive organism, than against the gram      cide applications.                                                             should be used. The most practical solu-
negative coliform organism. Quaternary           While the successful use of a poly-                                         tion of the problem appears to be through
I was more effective than Quaternary 11.      hedrosis as a means of controlling the al-                                     the use of trained entomologists as is done
Standard plate counts made with inclu-        falfa caterpillar may be expected in                                           in supervised control programs.
sion of the neutralizing agent, Congo         carefully planned and executed experi-                                            Clarence G. Thompson is Junior Insect Pathol-
Red, were slightly higher than where the      ments, its general use by the alfalfa                                          ogist in the Experiment Station, Berkeley.
qmternary alone was used, but when used       growers and commercial appliers of in-                                           Edward A. Steinhaus is Associate Professor of
on dairy equipment the total plate counts     secticides may entail some di5culties.                                         Insect Pathology and Associate Insect Patholo-
                                                                                                                             gist in the Experiment Station, Berkeley.
were all well within the limits of recom-     The timing of application may be so cri-
                                                                                                                               The above progress report is based on Re-
mended standards.                             tical that the average grower may not be                                       search Project No. 1306, being conducted by the
                                              in a position to determine when the virus                                      Division of Biological Control.
Studies on Rancidity
   Milk fat, under certain conditions, is                                        DONATIONS FOR AGRICULTURE RESEARCH
split into its component fatty acids some                        Gifts to the University of California for research by the College of Agriculture
                                                                                             accepted in March, 1950
of which have distinctive flavors and
odors. These lipolytic flavors, commonly                                                                          BERKELEY
called rancidity, are a source of much           California Spray-ChemicalCorporation. . .                  ...................... .$1,500.00
                                                                             Division of Entomology and Parasitology
financial loss to the dairy industry
                                                 Contra Costa Vegetable Oil Corp..                                   e sack (100 Ibs.) walnut meal
through loss or degrading of products.
Some of the most troublesome of these            Distillation Products Inc.            ..........................       . . . . . $5 Ih. mixed soy sterols
flavor defects occur in the winter months                                          Division of Poultry Hus
and are caused by the lipolytic enzyme           Lederle Laboratories Division American Cyanamid Co.
that has been designated as naturally ac-                                                            50 Ibs. animal protein factor feeding supplement
tive. Studies on the mode of action of this                                        Division of Poultry Husbandry
enzyme show that it is present in some           Pacific Vegetable Oil Corporation      ................................... lsackcopra meal
milks when the milk is drawn from the                                                   ion of Poultry Husbandry
cow, and that when that milk is cooled                                                                               DAVIS
the enzyme is adsorbed on the surface of         Bauer-Schweitzer Hop & Malt Co.. ...................                                             .....
the fat globule resulting in lipolysis.                                                            Division of Agronomy
These studies support the idea that this         California Committee on Relation of Electricity to Agriculture. ........                                                        . . . . .S3,12 5.00
naturally active enzyme is different from                                             Division of Agricultural Engineering
the lipolytic enzyme that is present in all      C. M. Goethe .............................................................                                                                 $100.00
                                                                                           Division of Animal Husbandry
milk which results in rancidity when raw
                                                 Kern County Land Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             $1,730.00
milk is homogenized.                                                                               Division of Agronomy
                                                 Miller Malting Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .          .$1,000.00
                                                                                                   Division of Agronomy
Solids-Not-Fat and Fat                           Pittsburgh Agricultural Chemical Corp.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .                 1 50* Drum Chlorosol A.
   Over 20,000 samples of milk have been                                                           Division of Agronomy
collected from within California and             The Union Ice Company. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .$500.00
analyzed for solids-not-fat and fat. The                                                   Division of Animal Husbandry
samples were from individual patrons             R. Volmer & Sons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     $200.00
                                                                                                   Division of Agronomy
collected at the dairy plant over a two-
year period and selected so as to be repre-                                                                     LOS ANGELES
sentative of the animals and the type of         Coast Agricultural Fertilizer Co.. .......................          150 Ihs. Better Grow Castor-Bean Meal
                                                                                  Division of Ornamental Horticulture
dairying in the region. The analyses show
that the solids-not-fat per cent of milk in      Randall Mills Corporation. . . . . . . . . . . . . . . . . . . . . . . . . . . . , 1 0 0 Ibs. of Ramco Bat Guano
                                                                                  Division of Ornamental Horticulture
California for the state as a whole can
be calculated by taking the number 7.62
                                                 E. I. du Pont de Nemours & Company. ..............................                                              ,400lbs. of “Nugreen”
and adding to it 0.31 times the per cent                                            Orchard Management
of fat in the milk. Thus, milk of 3.8% fat

16                                                                                                C A L I F O R N I A A G R I C U L T U R E , MAY, 1950