NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
December, 1953 ]
M.L.
MATHUR
AND
S.
V.
DESAI
241
This mixture may be fed at the rate of one ounce per day in case of growing
animals and two ounces per day or one to two per cent of the dairy mixture in case
of lactating animals.
SUMMARY
1. The calcium and phosphorus composition of the milk in high, medium and
low milking cows from the pre-calving period to the end of lactation, with reference
to any possible effect of the various feeds on it has been studied.
2. The curves for CaO and P 2 O 5 percentage for thirteen cows from pre-calving
period to the end of lactation have been shown on photographs. These indicated
that the composition of the milk was determined by the age, breed, individuality
and state of health and the time in the period of lactation of the cow. The mineral
contents of the ration did not directly effect the composition of the milk in a definite
way though it may effect the retention of the minerals by the cows. Similarly
fresh green fodder as compared to silage or hay prepared out of them, may effect
the assimilation of the minerals from them, but not the composition of milk.
3. The calcium and phosphorus contents of the milk were lower during the
flush period than in other period of lactation after calving.
4. Negative calcium and phosphorus balances in high milking cows were indicated
after two weeks of calving and were maintained for twenty to thirty weeks of lacata-
tion. The storage of calcium and phosphorus was possible as soon as the milk
production decreased to less than fifteen pounds per day.
5. The group of cows of low milking capacities giving about 4,500 pounds for
the whole lactation also lost calcium and phosphorus during the flush period when
the daily milk yield was about 25 pounds.
6. Seventy-five grams of CaO and 80 gm. P 2 O 5 were the minimum amounts
necessary in the feed of average milking cows giving about 20 pounds milk per day
to avoid losses of these minerals.
ACKNOWLEDGMENT
The authors are grateful to Mr. C. H. Parr, then Imperial Agriculturist and
Mr. N. P. Fernendez, Cattle Superintendent, for giving facilities to conduct the
experiments in his Division and for taking keen interest in the work.
REFERENCES
Desai, S. V. and Mathur, M. L. (1945). Indian J. vet. Sci. 3, 199
Mathur, M. L. and Desai, S. V. (1953). Indian J. vet. Sci. 23, 143-172
ASSIMILATION OF PHYTIN PHOSPHORUS BY DAIRY
COWS
By M. L. MATHUR, Indian Agricultural Research Institute, New Delhi
(Received for publication on 14 January, 1951)
I t has long been known that a large part of organic phosphorus of cereals and cakes
which are the principal constituents of concentrate mixtures usually fed to cows,
occurs in the form of phytic acid (inositolhexaphosphoric acid) or phytin which is
calcium magnesium salt of phytic acid. Starkenstein [1910] and Plimmer [1913]
were the earliest workers, who provided evidence, that phytin when fed to animals,
was not directly absorbed from the alimentary canal, but was simply hydrolysed
by bacterial action. Rather [1918] found that almost all phytin phosphorus fed to
pigs was hydrolysed and excreted in the form of orthophosphoric acid. Bruce and
Callow [1934] found that phytin phosphorus which was about 50 per cent in the diet
of rats was not available to them. McCance and Widdowson [1935] found that 20
to 60 per cent of the phytin fed to human beings was excreted unchanged in the faeces.
They suggested that the rest may also have been unabsorbed and present in other
forms in the faeces. Young, Gregory and Vere Jones [1935] found that part of
phytic acid phosphorus was hydrolysed in the stomach of rabbits and excreted as
inorganic phosphorus. Low and Steenbook [1936] also found that phytic acid was
partially available to rats on a low calcium ration but the addition of calcium
carbonate makes it almost completely unavailable. Kreigher and Steenbook [1940]
also confirmed that increase of Ca/P ratio from 1:1 to 2:1 decreased the availability
of phytic acid phosphorus.
It seemed desirable, therefore, to study the metabolism of phytin phosphorus
in milch cows. Generally about 80 per cent of the P 2 O 5 in the rations of dairy
cows, is present in the concentrated feed ; and more than 50 per cent of this is phytin
phosphorus. It would therefore be of great advantage to know (a) how far this
amount of phosphorus present in the concentrated feed met the requirements of
the animal, (b) whether it was necessary to add more phosphorus in the form of
mineral salts in the diet or improve the fodder by manuring it and (c) the influence of
calcium carbonate on the assimilation of phytin phosphorus.
EXPERIMENTAL
Four high milking Sahiwal cows of about the same age and at the same stage of
lactation were selected. All the cows received the same concentrated feed in different
quantities according to its requirements and fodders ad lib. according to the latin
square as shown in Table 1. Small amounts of wheat straw (2 to 4 lb.) were also
given to avoid loose faeces by the animals.
Out of the 12 days of each period, the first six days were non-experimental and
remaining six days experimental, when accurate account of feed consumed and
7 AR/53
243
5
244
ASSIMILATION
OF
PHYTIN
PHOSPHORUS
[ Vol. XXIII, Part IV,
faeces voided was kept. Each experimental day began at 8 a.m. and ended at 8 a.m.
on the next day. The animals were fed four times in 24 hours at the time of milking.
Each morning, the faeces were weighed, thoroughly mixed and samples taken for
analysis.
TABLE I
Feeding scheme of fodders
Name of the cow
Lenjurki
Larajbani
Haskila
Yulamati
Period I
28-3-46
to 8-4-46
A
B
C
D
Period II
9-4-46
to 20-4-46
B
C
D
A
Period III
21-4-46
to 2-5-46
C
D
A
B
Period IV
3-5-46
to 14-5-46
D
A
B
C
A=Unmanured berseem
B=Manured berseem—(4 maunds of (NH 4 ) 2 PO 4 per acre)
C=Lucerne
D=Jowar silage plus lucerne hay
The grain mixture which was the principal source of phytin phosphorus consisted
of the following:
Barley
Cowpeas
Wheat bran
Groundnut cake
Linseed cake
Salt
Chalk (CaCO 3 )
30 per cent
25 per cent
20 per cent
15 per cent
10 per cent
1.5 per cent
1.0 per cent
The average amount of grain mixture in pounds per day consumed by the cows
during the various periods is given in Table II.
TABLE II
Average consumption of grain mixture in pounds per day
Name of the cow
Lenjurki
Larajbani
Haskila
Yulamati
A
10
11
14
14
B
13
13
16
13.5
C
13
12
16
14
D
13
13
16
14
For the estimation of phytin, the method of Heubner and Stadler [1914] is
generally used. Rather [1917] used it for the estimation of phytic acid in plant
246
ASSIMILATION
OF
PHYTIN
PHOSPHORUS
[ Vol. XXIII, Part IV,
Knowles and Watkin [1932] recommended that sodium salicylate gave sharper
end points when used as an indicator, but ammonium thiocyanate was found better.
TABLE III
The distribution of phosphorus in the grain mixture and its components
Feed
Bran
Barley
Cowpeas
Linseed cake
Groundnut cake
Grain mixture
Phytin
phosphorus
per cent
0.893
0.116
0.063
0.304
0.411
0.321
Total
phosphorus
per cent
1.281
0.331
0.371
0.741
0.593
0.611
Total phos-
phorus as
P 2 O 5 per cent
2.934
0.757
0.849
1.698
1.359
1.399
It shows that 52.54 per cent of the total phosphorus in the grain mixture was
present in the form of phytic phosphorus.
While studying the mineral balances, it was observed that negative phosphorus
balances occurred in all animals during almost all periods, hence the distribution of
phytin was likely to throw some light on the unavailability of such large amount of
phosphorus.
The average daily amounts of phytic phosphorus present in the concentrate
mixture* and that excreted unchanged in the faeces during the various periods are
given in Table IV.
TABLE IV
Phytic phosphorus in concentrate mixture and faeces
Name of the cow
Lenjurki
Larajbani
Haskila
Yulamati
Mean
Phytic phosphorus (in
gm. per day) present in
concentrate mixture
A
14.5
18.9
23.3
19.7
19.2
B
18.9
16.0
23.3
20.4
19.6
C
18.9
18.9
20.4
20.4
19.6
D
18.9
17.2
23.3
19.8
19.8
Phytic phosphorus (in
gm. per day) excreted un-
changed in faeces (per-
centage of the intake
in brackets)
A
6.3
(43.0)
8.0
(42.4)
11.0
(47.2)
8.3
(40.9)
8.4
(43.4)
B
7.8
(41.4)
8.2
(51.1)
10.0
(43.1)
7.4
(36.3)
8.4
(43.0)
C
7.6
(39.9)
7.8
(41.1)
9.9
(48.7)
7.9
(38.6)
8.3
(42.0)
D
7.1
(37.5)
7.2
(41.6)
10.2
(43.8)
7.1
(34.8)
7.9
(39.4)
*The amount of phytin phosphorus present in the fodders consumed by the cows was between
0.23 to 0.29 gm. per day and hence it has not been taken into consideration.
December, 1953 ]
M.
L.
MATHUR
247
It will be seen from Table IV that 35 to 51 per cent of phytic phosphorus
was recovered unchanged and rest was hydrolysed. The grain mixture contained
30 per cent barley, and hence the enzymic cleavage of phytic acid by the enzyme
phytase, may have taken place in the intestine of the animals. It is assumed that
after hydrolysis or enzymic cleavage of phytic acid, the products are similar to other
inorganic forms found in green fodder and absorbed as such.
The reason, why such large amounts of phytic acid is withdrawn from metabolism
and not available to the cows, can also be explained. The diet of the animals contain-
ed large amount of calcium in chalk and it may be assumed that this calcium prevents
the splitting of phytic acid by precipitating it as calcium phytate in the small intes-
tine. Even if the enzyme is present in the food, the phytic acid which is precipitated
as calcium phytate is rendered unavailable to the action of phytase. Thus both
calcium and phosphorus are rendered unavailable for absorption in the system.
It would thus appear that excess of calcium depresses the absorption of phytic
phosphorus and at the same time excess of phytic acid also renders calcium un-
available. Considering these it would suggest that a suitable calcium phosphorus
ratio in the food should be aimed at. Table V gives the CaO : P 2 O 5 ratio in the food
during the experiments.
TABLE V
The CaO: P 2 O 5 ratio in the diet during the different periods
Name of the cow
Lenjurki
Larajbani
Haskila
Yulamati
Mean
A
1.85:1
1.96:1
2.04:1
2.00:1
1.96:1
B
2.09:1
1.73:1
1.73:1
1.99:1
1.88:1
0
2.18:1
1.86:1
1.70:1
1.74:1
1.86:1
D
1.29:1
1.29:1
1.29:1
1.07:1
1.23:1
When the Ca : P ratio in the feed was judged with the percentage of phytin
phosphorus metabolised it was found that the mean CaO : P 2 O 5 ratio during the
periods A, B, C, D, were 1.96, 1.88, 1.86, 1.23 and the phytin phosphorus metabolise
during the corresponding period were 56.6, 57.0, 58.0 and 60.6 per cent. It appeared
therefore that with the CaO : P 2 O 5 ratio approaching 1 : 1, more and more phytin
phosphorus was metabolised in the system of the cows.
TABLE VI
Phytin phosphorus calculated as P 2 O 5 in gm. per day in the grain mixture
Name of the cow
Lenjurki
Larajbani
Haskila
Yulamati
A
33.31
43.33
53.33
45.00
B
43.33
36.66
53.33
46.67
C
43.33
43.33
46.67
46.67
D
43.33
39.21
53.33
45.27
7 AR/53
6
248
ASSIMILATION OF PHYTIN PHOSPHORUS [ Vol. XXIII, Part IV,
TABLE VII
Phytin phosphorus calculated as P 2 O 5 in gm. assimilated or used per day
Name of the cow
Lenjurki
Larajbani
Haskila
Yulamati
Total for fodder
A
19.01
24.96
28.14
26.00
98.11
B
25.37
17.93
30.37
29.70
103.37
C
26.04
25.53
23.95
28.65
104.17
D
27.07
23.04
29.98
26.75
106.84
Total for
cows
97.49
91.46
112.44
111.10
Preliminary statistical analyses showed that there was strong variation in the
utilization of phytin phosphorus amongst the animals, but the differential effect
of fodders in inducing assimilation of phytin was small.
SUMMARY
1. The methods of the estimation of phytin have been discussed.
2. Balance experiment of phytin phosphorus in high milking cows has been
described.
3. Of the total phosphorus in the grain mixture 52.54 per cent was present in
the form of phytin phosphorus.
4. Of the total phytin phosphorus present in the feed of the cows, 35 to 51
per cent was recovered unchanged, while the rest was either metabolised,
or hydrolysed.
ACKNOWLEDGMENT
The author is grateful to Dr. S. V. Desai, I/C Division of Chemistry, Indian
Agricultural Research Institute, for his valuable suggestions and guidance during
the progress of the work. His thanks are also due to Mr. C. H. Parr, Imperial Agri-
culturist and Mr. N. P. Fernandez for providing facilities for conducting the experi-
ment at the, Dairy Farm.
REFERENCES
Andrews, J. S. and Bailey, C. H. (1932). Industr. Eng. Chem., 24, 80
Bruce, H. M. and Callow, R. K. (1934). Biochem. J., 28, 517
Harris, R. S. and Mosher, L. M. (1932). Industr. Eng. Chem. Anal Ed. 6, 320
Heubner, W. and Staddler, H. (1914). Biochem. Z. 64, 42
Knowles, F. and Watkins, J. E. (1932). J. Agric. Sci. 22, 755
Kreigher, C. H. and Steenbock, H. (1940). J. Nutrition, 20, 125
Low, J. T. and Steenbock, H. (1936). Biochem. J. 30, 1120
McCance, R. A. and Widdowson, E. M. (1935). Biochem. J. 29, 2694
Plimmor, R. H. A. (1913). Biochem. J. 7, 23
Rather, J. B. (1918). Ark. Agric. Exp. Sta. Bull. 147
Starkenstein (1910). Biochem. Z. 30, 56
Young, L. (1936). Biochem. J. 30, 252
Young, L., Gregory, R. A. and Vere Jones, N. W. (1935). Chem. Industr. 54, 270
FREEZING POINT OF COW AND BUFFALO MILK
IV. EFFECT OF SOME FACTORS ON THE FREEZING POINT OF MILK
By C. S. DHARMARAJAN, R. VENKATESWARA RAO and NOSHIR N. DASTUR, Indian
Dairy Research Institute, Bangalore
(Received for publication on 12 May 1953)
(With two text-figures)
T HE freezing point of milk is recognised to be the most reliable test for detect-
ing adulteration of milk with water. It is, therefore, desirable to study how
the value of freezing point varies due to natural causes, due to the addition of
adulterants and due to processing, and to see how these factors influence the inter-
pretation of the results. Some of these factors have been examined with milk of
western breeds [Elsdon and Walker, 1942 ; Department of Health, Scotland, 1943].
In a previous communication of the present series, Dharmarajan and co-workers
[1950] found the average value of the freezing point of cross-bred, Gir, Sahiwal,
Red Sindhi and Tharparkar cows' milk collected at Bangalore to vary from —0.546°
to —0.549°C. ; that of Murrah buffalo milk was —0.549°C. Thus there was no
appreciable difference in the average values of freezing point of milk from animals
of different breeds. In a further study [Venkateswara Rao, Dastur and Dharma-
rajan, 1950] it was shown that milk of cows and buffaloes collected from different
farms in India had a similar average value for freezing point, namely, —0.548°C.
In the present study the effect of some factors like stage of lactation, season, acidity
development; addition of common adulterants and the effect of processing on
the freezing point has been examined.
EXPERIMENTAL
Milk samples were obtained from animals maintained at the Indian Dairy
Research Institute Farm at Bangalore. Herd milk samples from cross-bred (Red
Sindhi × Ayrshire), Gir, Sahiwal, Red Sindhi and Tharparkar cows and Murrah
buffaloes, and individual samples from three Red Sindhi cows and two Murrah
buffaloes, were collected simultaneously as per details given by Dharmarajan, et
al. [1950]. In the same paper the methods followed for the determination of the
freezing point and titratable acidity of milk have also been given.
The variations in the freezing point of milk with the stage of lactation and
seasons are shown in Fig. 1 and 2 respectively. Some of the data illustrating the
change in the freezing point with the development of acidity in milk stored at 32°C.
are given in Tables I and II. Along with acidity determination, the samples were
tested by the boiling test. These results are also shown in these tables. Altogether
24 trials were carried out, each with cow and buffalo milk ; the results are summarised
in Table III.
249
7 AR/53
7
250
FREEZING POINT OF COW AND BUFFALO MILK
[Vol. XXIII, Part IV,
Fig. 1. Effect of stage of lactation on the freezing point of milk.
December, 1953] C. S. DHARMARAJAN, R. V. RAO AND N. N. DASTUR 251
Fig. 2. Variation in the freezing point of milk season
252
FREEZING POINT OF COW AND BUFFALO MILK
[ Vol. XXIII, Part IV,
TABLE I
Effect of development of acidity in cow milk on the freezing point
Sample number
Time interval (in hours)
Initial
4
5
6
7
8
Sample number
Time interval (in hours)
Initial
4
5
6
7
F. P.
0.544
0.544
0.552
0.560
0.567
0.590
F. P.
0.553
0.552
0.560
0.578
1
Aci-
dity
0.15
0.15
0.16
0.18
0.23
0.30
7
Aci-
dity
0.10
0.12
0.15
0.20
B. T.
—
—
—
—
+
+
B. T.
—
—
—
+
F. P.
0.550
0.550
0.552
0.573
0.605
F. P.
0.524
0.548
0.555
0.570
2
Aci-
dity
0.13
0.14
0.14
0.22
0.30
8
Aci-
dity
0.12
0.14
0.15
0.21
B. T.
—
—
—
+
+
B. T.
—
—
—
+
F. P.
0.542
0.547
0.558
0.568
0.610
0.660
F. P.
0.535
0.554
0.570
0.588
3
Aci-
dity
0.14
0.14
0.18
0.22
0.27
0.36
9
Aci-
dity
0.10
0.15
0.20
0.26
B. T.
—
—
—
+
+
+
B. T.
—
—
+
+
P. P.
0.535
0.543
0.543
0.570
0.575
P. P.
0.540
0.545
0.560
0.582
0.595
4
Aci-
dity
0.12
0.13
0.14
0.22
0.25
10
Aci-
dity
0.11
0.13
0.17
0.25
0.32
B. T.
—
—
—
+
+
B. T.
—
—
+
+
+
F. P.
0.550
0.550
0.564
0.587
0.605
F. P.
0.544
0.548
0.550
0.572
0.595
5
Aci-
dity
0.14
0.16
0.18
0.28
0.35
11
Aci-
dity
0.10
0.12
0.13
0.18
0.26
B. T.
—
—
+
+
+
B. T.
—
—
—
+
+
F. P.
0.540
0.540
0.550
0.559
0.590
F. P.
0.545
0.548
0.550
0.555
0.585
6
Aci-
dity
0.13
0.13
0.15
0.22
0.32
12
Aci-
dity
0.12
0.13
0.13
0.15
0.21
B. T.
—
—
—
+
+
B. T.
—
—
—
—
+
F. P.=Freezing point in—degrees C
B. T. = Boiling test
Acidity=Percentage lactic acid
December, 1953 ] C. S. DHARMARAJAN, R. V. RAO AND N. N. DASTUR 253
TABLE II
Effect of development of acidity in buffalo milk on the freezing point
Sample number
Time interval (in hours)
Initial
4
5
6
7
8
Sample number
Time interval (in hours)
Initial
4
5
6
7
8
1
F. P.
0.553
0.555
0.560
0.570
0.577
F. P.
0.564
0.570
0.593
0.620
Aci-
dity
0.12
0.12
0.13
0.15
0.18
7
Aci-
dity
0.10
0.13
0.21
0.24
B. T.
—
—
—
—
+
B. T.
—
—
+
—
2
F. P.
0.542
0.542
0.544
0.554
0.584
F. P.
0.540
0.545
0.550
0.554
0.575
Aci-
dity
0.13
0.13
0.13
0.16
0.24
8
Aci-
dity
0.11
0.11
0.12
0.14
0.19
B. T.
—
—
—
+
+
B. T.
—
—
—
—
+
3
F. P.
0.555
0.555
0.566
0.570
0.590
0.635
F. P.
0.545
0.545
0.555
0.570
Aci-
dity
0.10
0.10
0.13
0.15
0.20
0.29
9
Aci-
dity
0.13
0.13
0.13
0.18
B. T.
—
—
—
+
+
+
B. T.
—
—
—
+
4
F. P.
0.544
0.544
0.543
0.543
0.553
0.570
F. P.
0.555
0.560
0.580
0.625
Aci-
dity
0.09
0.09
0.09
0.10
0.13
0.14
10
Aci-
dity
0.13
0.16
0.20
0.29
B. T.
—
—
—
—
—
+
B. T.
—
—
+
+
5
F. P.
0.545
0.545
0.557
0.570
0.620
F. P.
0.555
0.565
0.585
0.595
Aci-
dity
0.09
0.09
0.12
0.15
0.25
11
Aci-
dity
0.14
0.16
0.19
0.26
B. T.
—
—
—
+
+
B. T.
—
—
+
+
6
F. P.
0.551
0.551
0.552
0.562
0.582
F. P.
0.545
0.550
0.560
0.560
0.578
0.590
Aci-
dity
0.09
0.09
0.09
0.12
0.16
12
Aci-
dity
0.10
0.11
0.13
0.13
0.17
0.22
B. T.
—
—
—
—
+
B. T.
—
—
—
—
+
+
F. P.=Freezing point in—degrees C
B. T.=Boiling test
Acidity=Percentage lactic acid
254
FREEZING POINT OF COW AND BUFFALO MILK
[ Vol. XXIII, Part IV,
TABLE III
Changes in the freezing point of cow and buffalo milk due to natural souring
Cow milk samples
Ser i al number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Increase in
F. P. due to
developed
acidity
(°C.)
0.006
0.010
0.013
0.014
0.014
0.019
0.020
0.023
0.023
0.024
0.024
0.025
0.025
0.026
0.026
0.028
0.035
0.035
0.035
0.035
0.035
0.037
0.040
0.046
Increase in
acidity at
positive
boiling test
stage (per cent
lactic
acid)
0.02
0.06
0.06
0.04
0.02
0.09
0.06
0.08
0.09
0.10
0.04
0.10
0.09
0.08
0.07
0.08
0.10
0.09
0.10
0.10
0.06
0.12
0.09
0.09
Average
Increase in
P. P. per
0.01 per cent
increase
in acidity
0.0030
0.0017
0.0022
0.0035
0.0070
0.0021
0.0033
0.0029
0.0026
0.0024
0.0060
0.0025
0.0028
0.0033
0.0037
0.0035
0.0035
0.0039
0.0035
0.0035
0.0058
0.0031
0.0044
0.0051
0.00365
Buffalo milk samples
Increase in
F. P. due to
developed
acidity
(°C.)
0.012
0.012
0.013
0.015
0.016
0.020
0.024
0.025
0.025
0.025
0.025
0.026
0.028
0.029
0.030
0.030
0.031
0.033
0.035
0.035
0.035
0.036
0.045
0.046
Increase in
acidity at
positive
boiling test
stage (per cent
lactic
acid)
0.04
0.03
0.05
0.15
0.05
0.07
0.06
0.07
0.06
0.05
0.07
0.09
0.08
0.10
0.05
0.05
0.08
0.07
0.10
0.08
0.09
0.13
0.12
0.16
Average
Increase in
F. P. per
0.01 per cent
increase
in acidity
0.0030
0.0040
0.0026
0.0030
0.0032
0.0029
0.0040
0.0036
0.0042
0.0050
0.0036
0.0029
0.0035
0.0029
0.0060
0.0060
0.0039
0.0047
0.0035
0.0044
0.0039
0.0028
0.0038
0.0029
.00378
For study with separated milk, whole milk was separated in a cream separator.
The fat in skimmed milk varied from 0.01 to 0.05 per cent. The effect of separa-
tion on the freezing point is shown in Table IV.
Milk was heated by the following methods to study the effect of heat on the
freezing point of milk : (a) Pasteurised by the holding method at 145°F. for 30
minutes and chilled to 50°F. (b) Pasteurised by the H. T. S. T. method at 165°F.
for 15 seconds and chilled to 50°F. (c) Milk brought to first boil in a covered alu-
minium vessel and cooled to room temperature by immersion in water. (d) Milk
boiled as above, allowed to simmer for five minutes and then cooled to room tempera-
ture by immersion in water. (e) Milk was heated as under (c) and (d) and the
freezing point of milk was determined soon after cooling. In another set of trials
milk after boiling and simmering for a minute was cooled to room temperature and
December, 1953 ] C. S. DHARMARAJAN, R. V. RAO AND N. N. DASTUR 255
TABLE IV
Effect of skimming on the freezing point of milk
Sample number
1
2
3
4
5
6
7
8
9
10
11
12
F. P. of whole
milk
—°C.(A)
0.540
0.548
0.541
0.548
0.544
0.543
0.533
0.542
0.545
0.550
0.550
0.550
F. P. of skim-
med milk
—°C. (B)
0.541
0.546
0.540
0.545
0.544
0.544
0.533
0.541
0.544
0.550
0.548
0.549
Difference
(A—B)
—0.001
+0.002
+0.001
+0.003
0.000
—0.001
0.000
+0.001
+0.001
0.000
+0.002
+0.001
Fat percentage
in milk
4.90
5.40
3.90
5.70
5.40
5.15
6.10
5.10
5.40
7.10
7.30
5.00
Fat percentage
in skimmed
milk
0.05
0.05
0.05
0.05
0.05
0.05
0.01
0.05
0.05
0.05
0.05
0.05
then allowed to stand for five hours. The freezing point was determined at
intervals to see whether the soluble constituents of milk attain equilibrium at once
after boiling or some time is needed to reach the equilibrium. The results of the
effect of different methods of processing are given in Tables V and VI.
TABLE V
Effect of processing on the freezing point of milk
Sample
number
1
2
3
4
5
6
7
8
Average
Cow milk
Fresh
(—°C.)
0.544
0.543
0.550
0.545
0.540
0.545
0.558
0.542
0.546
Pasteu-
rised
holding
method
(—°C. )
0.544
0.540
0.550
0.550
0.539
0.545
0.558
0.538
0.547
Pasteu-
rised
H.T.S.T.
method
(—°C.)
0.545
0.540
0.549
0.547
0.541
0.548
0.562
0.539
0.546
Boiled
(—°C.)
0.548
0.550
0.560
0.553
0.555
0.553
0.570
0.550
0.555
Boiled
and
simmered
for
5 minutes
(—°C.)
0.572
0.576
0.590
0.596
0.590
0.563
0.610
0.583
0.585
Fresh
(—°C.)
0.562
0.539
0.536
0.539
0.560
0.562
0.565
0.560
0.553
Buffalo milk
Pasteu-
rised
holding
method
(—°C.)
0.564
0.540
0.536
0.536
0.560
0.560
0.567
0.562
0.553
Pasteu-
rised
H.T.S.T.
method
(—°C.)
0.564
0.540
0.538
0.535
0.559
0.561
0.565
0.562
0.563
Boiled
(—°C.)
0.578
0.544
0.548
0.550
0.565
0.570
0.575
0.590
0.565
Boiled
and
simmered
for
5 minutes
(—°C.)
0.583
0.570
0.570
0.570
0.586
0.590
0.595
0.610
0.583