NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
THE INFLUENCE OF DIETARY CAROTENE UPON THE
CAROTENE AND VITAMIN-A CONTENTS AND THE
REICHERT AND IODINE VALUE OF BUTTER-
FAT, WITH SPECIAL REFERENCE TO
SEASONAL VARIATIONS
BY
SAILENDRA MOHAN DAS GUPTA, M. Sc., Ph.D.
Department of Chemistry, Medical College, Calcutta
(Received for publication on 18th February 1939)
IN a previous paper [Wilson, Das Gupta and Ahmad, 1937] studies were
made on the absorption of carotene in the human subject. In this paper, at-
tempts have been made to study the absorption of the hydrocarbon in animals,
particularly the cow, which is the main live-stock in India, under typical In-
dian conditions. The absorption of carotene by the cow is dependent to a
large extent on carotene content of the feed. This can be seen from a study
of the carotene and vitamin-A contents of milk or milk-fats which increase or
decrease according as their contents in the feed are high or low. It was, there-
fore, thought advisable to study the problem by assaying the milk-fats for their
carotene and vitamin-A contents. This will no doubt give an approximate
idea of the problem, for except for the colostrum which gives abnormal values
for carotene and vitamin-A, the values are not appreciably affected either by
the stage of lactation of the cow or temperature differences. Studies in the
absorption by such methods are also important from the view-point of human
nutrition, for milk-fat or ghee is the chief source of vitamin-A which is so essen-
tial for the health of the population in India. Much work has been done in
foreign laboratories in this direction, but unfortunately in India, no systematic
work has yet been attempted on this important aspect of nutrition. In this
paper, the experiments have been confined to the typical dietary conditions
prevalent in Bengal. During the autumn, the cows mainly live upon paddy
straw as the main roughage, which the cows eat readily without any discom-
fort. Small amounts of concentrate like rape-seed cake are also given. The
diet, therefore, contains a very small amount of carotene. The method of
storing the paddy straw further destroys the carotene content of the straw.
During the winter, the cows get a good supply of grass and other leafy vegeta-
bles of high carotene content. This is apparently unlike what happens in
western countries where the cows get the minimum amount of carotene during
the winter. It will thus be seen that the cows in Bengal either live upon grass
or paddy straw or mixtures of these two in different proportions according to
the availability of the two roughages during the different parts of the year,
( 249 )
250 Carotene and Vitamin-A Contents of butter-fat in cows
During recent years, attempts are being made in India to improve the quality
of ghee or clarified butter-fats which undergo marked seasonal variations parti-
cularly during the autumn and the winter seasons. Thus it is stated that the
best ghee is produced during the winter (from November to early part of March)
and that ghee produced during the monsoon (July to October) is of definitely
inferior quality [Wright, 1937]. It is in the quality of the ghee and not the
quantity that the real improvement of it lies. In this paper, the changes due
to seasonal variations and the effects of feeding cows with different mixtures
of grass and straw and red palm oil on the carotene and vitamin-A contents
of butter-fat have been studied. The Reichert values and Iodine number of
butter-fats are two important characteristics of butter-fats which determine
their quality. It was, therefore, thought advisable to determine these two
values also along with the carotene and vitamin-A contents of butter-fats.
I—EXPERIMENTAL
Effect of feeding cows with varying mixtures of grass and straw on the
various characteristics of butter-fats. For this purpose, two healthy cows were
used. They were of the same breed (the common humped domestic cattle of
Bengal), almost of the same age (four years), same period of lactation (three
months). Their body-weights were approximately 500 lb. and milk-yield
about 4 lb. per day (morning and evening). During the experimental period,
which lasted for two months, the animals were kept in a stall. The stall
arrangements and metabolic procedures were broadly similar to what are ordi-
narily used in such experiments.
The feeding experiment was divided into four periods.
Period I.—(2 weeks) Basal diet consisting of a mixture of grass and straw
in the proportion 1 : 1 by weight.
Period II.—(3 weeks) only grass as the roughage in the case of cow D 2
and only straw in the. case of cow D 1 .
Period III.—(one week) same as period I.
Period IV.—(2 weeks) only grass in the case of cow D 1 and straw-chops in
the case of cow D 2 . The details are given in the following scheme :—
Period
I
II
III
IV
No. of weeks
1st and 2nd weeks .
3rd, 4th and 5th weeks .
6th week . . .
7th and 8th weeks . .
Nature of feed
In these weeks, both the cows (D 1 and D 2 ) were
fed ad lib. with a mixture of grass (Cynodon
dactylon) and paddy straw (Aman variety) in
the morning and evening. As concentrate,
1 lb. of linseed cake was also given along with
the roughage to each cow.
In these weeks, cow D 1 was fed ad lib. with straw
alone and cow D 2 on grass alone as the roughage
during the morning and evening. The con-
centrate was similar to period I.
Same as period I.
In these weeks, Cow D 1 was fed ad lib. with grass
alone and cow D 2 with straw alone as the
roughage. The concentrate was similar to
period 1.
Ind. Jour. Vety. Sci. & Anim. Husb., Vol. IX, Part II ]
PLATE VIII
Ventral view of Waretrema piscicola
Key to Lettering.
D. h.
Eg.
G.p.
H.s.
I.c.
Mt.
O.
. . Ductus hermaphroditicus.
. . Egg.
. . Genital pore.
. . Hermaphroditic sac.
. . Intestinal caecum.
. . Metraterm.
. . Ovary.
P. gl.
P. p.
R. s.
T.
V. s. e.
V. s. i.
Vt.
.. Prostate gland.
.. Pars prostatica.
. . Receptaculum seminis.
.. Testis.
.. Vesicula seminalis externa.
.. Vesicula seminalis interna.
.. Vitellaria.
Ind. Jour. Vety. Sci. & Anim. Husb., Vol. IX, Part II ]
PLATE IX
Magnified view of hermaphroditic sac and vesicula seminalis externa of
Waretrema piscicola
(for key to lettering see plate VIII )
Ind. Jour. Vety. Sci. & Anim. Husb., Vol. XI, Part II ]
PLATE X
'Deg-Nala' disease. Lesions of posterior limbs
S. M. DAS GUPTA 251
The butter from the composite milk was churned out on the last day of
each week, clarified as described below, and sealed with paraffin.
The morning and evening milks (about 4 lb. per cow) were collected on the
last day of each week and the cream separated in a small cream separator.
The butter was churned from the sweet cream in a glass experimental churn
by hand. The butter thus obtained was washed with distilled water and then
taken on a muslin cloth and the excess water (butter-milk) pressed out, It-
was melted at 50°C, the curd skimmed off and the middle layer taken off by a
pipette. It was further filtered through a layer of cotton wool when the yellow
colour of the butter was prominent. It was then kept in bottles sealed with
paraffin in the dark. The results are given in Table I. It may be noted
here that in common with other fat-soluble vitamins, carotene and vitamin-A
are separated completely from milk or cream by churning out the fat and they
are not in the least affected by ordinary heating [Davies, 1936].
METHODS OF ESTIMATION
Determination of Reichert and Iodine values. Samples of butter-fats
analysed were pure and fresh and kept in bottles sealed with paraffin in the
dark until required for analysis. The Reichert-Wollny values were determined
by standard American A. O. A. C. methods with all the necessary precautions.
The Iodine number was determined by the Wijs' method. Before determina-
tion of these values, a portion of the sample of butter was heated to 55°C in a
bottle until the fat separated from the water and curd. The fatty layer was
filtered through coarse cotton-wool. The fat was liquefied before use and ex-
posure of the melted fat to the air was as short as possible.
The results given in the tables indicate the mean of 2 values. In the case
of the blank experiments, the values varied from 0.2 c.c. to 0.4 c.c. which were
deducted from the actual experimental values. Acid values of some of the
butter-fats were also determined and were found to lie between 0.062 c.c. to
0.086 c.c. (in oleic acid per cent), which showed that the butter-fats analysed
were free from any rancidity.
Determination of carotene content of butter-fats. The carotene content of
butter was determined by the following way :—The fat was melted at 55°C
and then filtered through cotton-wool. One c.c. of the melted fat was dis-
solved in 3 c.c. of light petroleum ether (B. P. below 40° C). The carotene
was then estimated colorimetrically with the help of a Lovibond tintometer.
Example.—To 1 c.c. of melted butter was added 3 c.c. of petroleum
ether. The solution was found to be equivalent to 2.2. Y. U. 0.2 R. U.
(neglected). The specific gravity of the fat being taken as 0.9, the yellow
unit per grm. of the fat will be given by 4 × 2.2 / 0.9 = 9.8 Lovibond
Yellow Unit (Y. U.) per grm. of butter, corresponding to a 1 cm. thickness
252 Carotene and Vitamin-A Contents of butter-fat in cows
of the fat. As Xanthophyll only constitutes 1/15th of the total yellow colour
of butter-fats, no attempt was made for its estimation [Ferguson and Bishop,
1936].
Determination of Vitamin-A content of butter.—By carrying out some
preliminary experiments, it has been found that the blue-value on the un¬
saponifiable fraction gives higher and more concordant results than the value
without saponification, probably because of the removal of colour inhibitors.
After a number of trials the following method has been found to give satisfac-
tory results.
Procedure.—About 10 grm. of the clear and filtered fat was weighed into
an Erlenmeyer flask and then saponified with an equal amount of 66 per cent
alcoholic KOH solution and 20 c.c. of alcohol. The process was carried out
electrically for half an hour carefully. The flask was then cooled and 75 c.c.
of the distilled water added. The contents were poured into a separating fun-
nel and the flask washed with 100 c.c. of ether (peroxide free) and then poured
into the funnel. On carefully shaking the funnel the fatty residue, carotene
and vitamin-A present in the digest passed into the ether layer. Sometimes
it happened that the ether layer did not separate well and the whole mass
formed an emulsion. This was prevented by adding a little alcohol when
the ether layer separated out quickly. This was then separated, washed
twice with distilled water, 3 per cent KOH solution, 1 : 10 HC1 and finally
two times with water and it was then dried by filtering through a layer of
anhydrous sodium sulphate (B. D. H.) and evaporated, in an atmosphere of
carbon dioxide. The resultant fatty residue was at once dissolved in 1 c.c. of
chloroform. To 0. 2 c.c. of the solution was added 2 c.c. of SbCl 3 solution (30
per cent solution of SbCl 3 in dry CHCl 3 ) and the blue colour matched quickly
in a Lovibond tintometer. Results were then calculated in Moore's units
as follows :—
Example.—10 grm. (nearest to 0.1 grm.) of butter were digested and the
extracted residue was dissolved in 1 c.c. of CHCL 3 . 0.2 c.c. of this solution
was treated with 2 c.c. of SbCl 3 reagent, which gave a reading of 3.8 B. U.,
0.6 Y. U. and 0.7 R. U. Then the blue unit per grm. of the butter-fat is given
by 3. 8 × 2. 2 / 0. 2 × 10 = 4.10 Lovibond Blue Units (B. U.) per grm. of the butter-fat
corresponding to a 1 cm. thickness of the fat.
The estimation of carotene in milk, grass and fodders was carried out by
the method of Ferguson & Bishop [1936].
All the vitamin-A contents of butter-fats set out in the tables are given in
Lovibond Blue Units (B. U.) and carotene contents in Lovibond Yellow Units
(Y. U.) per grm. of the fat corresponding to a 1 cm. thickness of the fat. The
determinations of carotene and vitamin-A in butter were always carried out
in duplicate. The results given in following tables represent the mean of 2
readings which did not differ by more than 0.2 Y. U. or B. U.
S. M. DAS GUPTA 253
TABLE I
Results of analyses of melted butter-fats of two cows on rations containing different
amounts of grass and straw
(Cow No. D 1 .)
Week
1st week . . .
2nd „ . . . .
3rd „ . . . .
4th „ . . . .
5th „ . . . .
6th „ . . . .
7th „ . . . .
8th „ . . . .
1st week . . .
2nd „ . . . .
3rd „ . . . .
4th „ . . . .
5th „ . . . .
6th „ . . . .
7th „ . . . .
8th „ . . . .
Date on
which the
milk was
collected
12-2-37
19-2-37
25-2-37
1-3-37
7-3-37
13-3-37
19-3-37
25-3-37
R. W.
(Mean for
2 values)
26.4
26.2
25.2
24.8
24.8
24.1
25.6
26.8
(Cow No. D 2 )
12-2-37
19-2-37
25-2-37
1-3-37
7-3-37
13-3-37
19-3-37
25-3-37
26.6
26.4
27.0
27.8
29.4
29.2
27.8
26.6
I. N.
(Mean for
2 values)
35.8
36.2
36.4
35.8
35.9
37.8
35.6
34.8
34.7
35.8
35.6
34.4
33.8
33.6
33.8
34.2
Carotene
(Y. U.).
per grm.
3.8
3.2
3.3
3.8
3.4
4.8
5.4
5.2
3.6
4.2
5.8
6.6
7.4
7.5
6.6
5.6
Vitamin.
A (B. U.)
per grm.
6.8
6.6
6.8
6.1
7.8
8.3
8.4
8.6
7.2
8.8
9.6
10.8
11.4
12.2
11.8
9.8
II—SEASONAL VARIATIONS IN THE CAROTENE AND VITAMIN-A CON
OF BUTTER-FAT
Selection of butter—For the present study the author selected Vikrampur
(an important commercial centre for butter-fats in Bengal) as a suitable
place for the present investigation for the following reasons :—
1. The cows are of the same breed (the common domestic humped cattle
of Bengal) and are usually kept under good conditions. Moreover, there are
no buffaloes in Vikrampur so that adulteration with buffalo-butter is not
probable.
2. The cows usually live upon grass and stored paddy straw throughout
the year and only small amount of concentrate like oil-cakes, rice kura, etc.,
are given.
3. The cows are milked twice, in the morning and in the evening, by
the same dairyman and the times of milking are quite uniform (6-7 A.M. in
the morning and 4-5 P.M. in the evening).
254 Carotene and Vitamin-A Contents of butter-fat in cows
4. There is no definite period for calving in Vikrampur. Enquiries show
that the cows are calved in such a way that the total milk output of the dairy
remains practically the same. This might minimise the effect of the period of
lactation on the composition of the milk to some extent.
5. During the rains, most of the grazing fields of Vikrampur are under
water and the cows live upon mainly stored paddy straw, small amount of grass
and sometimes green leaves of the water-hyacinth. Only small quantities of
oil-cakes, middlings, husk, etc., are given which do not influence the characteris-
tics of the butter-fat to any appreciable extent especially of the Reichert¬
values (Report No. 66 of the University of Leeds and Yorkshire Council for
Agricultural Education). But during the winter (from November), the cows
are put out to grass during the day time. The fields are especially rich in
green vegetables e.g., Kalaisak rich in carotene (6.6 mg. per 100 grm. of
fresh sak) from November to February as the rice harvest is then over. Quite
reverse is the case with European countries where the cows are stabled during
the winter and are fed with rations of low carotene content. It may be noted
here, that the carotene content of grass as well as the stored paddy-straw
undergo marked variations throughout the year. During the autumn, the
carotene content of the paddy straw which has been stored during the winter
is negligible. The results of analyses of fresh samples of cow's butter
from mixed milk of several cows collected from dairies in different parts of
Vikrampur (Dacca) are given in Table II.
TABLE II
Results of analyses of butter-fats from mixed milk (morning and evening) of a
large herd
(The samples were collected from dairies in different parts of Vikrampur during
the year 1937-1938. The average temperature during July, August, September and
October was about 86° F. and that during November, December, January and
February was about 72° F.)
Month of preparation
July . . . .
No. of
samples
1
2
3
4
5
6
7
8
9
R. W.
(Mean of
2 values)
25.0
24.2
23.8
22.6
22.8
23.6
24.8
24.8
25.2
I. N.
(Mean of
2 values)
36.7
37.7
37.8
38.2
38.1
37.8
35.4
36.3
36.8
Carotene
(Y. U.)
per grm.
2.8
2.6
1.1
2.8
2.2
2.4
2.8
2.9
2.9
Vitamin-A
(B. U.)
per grm.
4.7
3.3
3.2
4.4
4.4
4.8
3.8
3.6
3.9
S. M. DAS GUPTA 255
TABLE II—contd.
Month of preparation
August . . . .
September . .
October . .
No. of
samples
10
11
12
13
1
2
3
4
5
6
7
8
9
10
11
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
10
11
12
13
14
R. W.
(Mean of
2 values)
22.0
25.4
23.6
24.8
22.2
23.8
26.6
22.2
25.2
21.4
24.6
23.2
23.8
22.5
21.6
23.8
23.4
22.3
23.8
28.2
23.8
22.8
23.6
22.2
22.8
21.8
23.6
27.4
22.2
21.8
28.8
21.4
23.8
28.2
23.2
22.8
22.2
21.6
24.6
23.8
21.2
22.3
23.4
22.8
23.8
I.N.
(Mean of
2 values)
38.8
35.6
37.7
36.2
38.7
37.2
34.8
38.9
36.4
39.8
36.4
37.8
38.0
38.3
38.8
37.8
37.9
38.5
37.8
35.2
37.8
..
37.1
38.0
38.0
40.4
38.8
34.6
38.3
39.7
33.6
39.2
27.8
33.6
37.4
37.7
38.6
38.8
36.6
37.0
39.8
38.5
37.2
37.2
37.9
Carotene
(Y. U.)
per grm.
2.8
2.8
1.0
2.5
2.6
2.8
3.8
2.2
2.6
0.6
1.4
2.8
1.4
2.8
1.6
2.2
1.2
0.8
1.2
3.2
1.3
0.6
0.0
1.1
1.2
0.4
1.4
2.8
1.8
1.6
3.2
1.2
0.2
1.6
1.8
2.6
1.6
1.8
1.4
1.6
1.2
0.0
2.6
2.8
1.4
Vitamin-A
(B. U.)
per grm.
2.8
2.6
1.8
2.6
2.8
1.8
2.8
4.2
4.6
2.2
4.6
3.2
2.2
3.6
2.2
2.6
2.8
1.2
2.9
5.6
2.4
3.0
1.2
3.5
2.2
3.6
2.8
4.6
3.6
2.8
4.5
2.3
2.8
3.8
2.8
2.8
2.1
2.2
1.4
1.4
1.3
2.0
2.3
2.2
2.6
B
256 Carotene and Vitamin-A Contents of butter-fat in cows
TABLE II—contd.
Month of preparation
November . . .
December . . .
January
.
.
.
.
February
.
.
.
.
No. of
samples
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
2
3
4
5
R.W.
(Mean of
2 values)
28.2
23.6
26.8
25.6
27.6
26.8
27.4
26.8
27.4
25.8
28.6
28.8
27.6
27.8
28.6
27.4
27.8
26.2
29.8
27.2
30.2
27.8
28.8
30.2
27.7
25.8
26.3
26.5
29.6
27.8
26.5
29.4
26.7
28.8
26.8
27.9
26.4
29.0
28.8
27.6
26.5
25.8
29.2
I.N.
(Mean of
2 values)
33.2
37.2
24.5
35.8
34.4
34.8
34.7
34.9
34.0
35.2
32.6
32.4
33.7
34.6
33.2
34.8
33.4
35.2
31.3
34.8
31.6
33.9
32.2
31.1
33.8
35.6
35.2
34.6
33.2
33.1
34.6
32.7
34.8
32.4
34.2
32.2
34.8
32.2
34.2
34.8
36.2
36.6
33.6
Carotene
(Y. U.)
per grm.
5.4
1.4
4.4
5.6
6.4
4.6
6.6
4.4
6.6
4.8
7.8
7.9
5.6
6.8
6.7
6.1
5.6
4.8
7.8
6.1
8.8
6.3
7.8
7.8
5.6
6.1
4.8
5.6
6.8
7.2
5.1
7.4
6.8
..
5.9
6.1
4.1
7.2
4.8
6.2
6.7
5.2
5.8
Vitamin-A
(B.U.).
per grm.
5.6
4.4
7.6
8.2
5.2
8.8
8.2
8.6
8.8
9.8
7.4
8.4
8.4
9.9
6.8
8.4
8.4
5.6
9.2
8.3
12.2
9.6
8.2
8.8
8.2
8.6
7.2
5.8
8.8
9.2
8.2
10.4
7.8
8.9
9.8
6.8
7.3
9.8
8.3
7.7
6.8
6.2
9.4
S. M. DAS GUPTA 257
TABLE II—contd.
Month of preparation
February—contd.
No. of
samples
6
7
8
9
10
11
12
13
14
15
R. W.
(Mean of
2 values)
28.2
27.6
27.2
29.2
26.9
27.0
30.8
26.2
27.2
27.1
I.N.
(Mean of
2 values)
34.6
34.7
35.5
33.4
35.8
35.3
31.2
35.2
36.8
35.8
Carotene
(Y. U.)
per grm.
5.9
4.8
4.6
5.2
5.6
5.8
8.6
6.3
6.4
5.2
Vitamin-A
(B. U.)
per grm.
8.6
8.8
7.6
6.3
6.8
7.2
8.2
8.5
8.8
7.8
In order to be sure of the results obtained in this paper, the butter from a
a single cow (Sundari) during September to January had been analysed. These
were clarified at 50° C. in an air oven in the laboratory. During September
and October, the cow mainly lived upon straw-chops whereas during November
to January she had been on pasturage during the day time.
TABLE III
Results of analyses of samples of cow's butter-fats made from the composite
milk of a single cow, aged 4 years 6 months and having its last calving in
June 1937.
(The milks were collected after a week. During September and October 1937, the
Cow mainly lived on paddy-straw. From November, the cow was put out to grass
till January, 1938.)
Month
September . . .
October
.
.
.
.
November . . .
December . . .
January
.
.
.
.
No. of
samples
1
2
3
4
1
2
3
1
2
3
1
2
1
2
R.W.
(Mean of
2 values)
24.2
25.7
23.8
24.7
22.6
21.8
21.4
29.8
28.6
27.2
26.6
26.8
25.2
24.2
I.N.
(Mean of
2 values)
35.6
34.4
36.1
26.3
38.8
39.6
38.8
33.1
32.1
35.4
36.0
36.2
36.6
36.8
Carotene
(Y. U.)
per grm.
1.2
1.6
0.8
1.8
2.4
2.6
1.0
4.8
5.6
5.8
5.4
4.4
4.8
2.6
Vitamin-A
(B. U.)
per grm.
3.2
3.6
3.8
2.6
4.8
5.2
2.8
8.6
8.2
8.8
6.4
6.8
5.8
4.6
258 Carotene and Vitamin-A Contents of butter-fat in cows
Effect of clarification, storage, etc. on the various characteristics of butter-fats
Clarification affects the carotene and vitamin-A contents of butter-fats
only to a small extent. Continuous heating (e.g., indigenous method of
preparing butter from curdled boiled milk or dahi) might lead to a serious
destruction of them. Storage for a short time (up to one month) does not
impair the contents to any appreciable extent but if preserved for longer
periods, a considerable loss might occur. In one or two cases the carotene
and vitamin-A contents were found to be destroyed within a few days. It
may be noted here that the carotene and vitamin-A do not appear to be
affected by pasteurisation and whatever has been found by some is insignifi-
cant [ Davies, 1936 ].
In some of the butter-fats giving low and high Reichert-Wollny values,
the Polenske values and Refractive index by the Butyro-Refractometer were
determined. The values, however, found to be perfectly normal as will be
seen from Table IV. The increase in the Iodine values with storage in Table
VIII appears to be rather unusual.
TABLE IV
Relation of Reichert-value, Iodine number, Polenske value and Refractive
Index of butter-fats
Sample No.
1
2
3
4
5
Reichert¬
Wollny
value
21.6
22.8
21.4
30.2
30.8
Iodine No.
38.8
37.2
39.8
32.1
32.2
Polenske value
1.5
1.6
1.4
2.9
3.1
Butyro¬
Refractometer
reading
at
40°C.
43.8
43.6
43.8
41.1
41.4
S. M. DAS GUPTA 259
TABLE V
Relation between carotene and vitamin-A contents of milk and butter churned
therefrom
Milk
No. of sample
1
2
3
4
5
6
Carotene
(Y. U.)
per grm.
of
ether
extracted
fat
3.4
3.8
4.2
3.6
4.2
4.6
Vitamin-A
(B. U.)
per grm.
of
ether
extracted
fat
8.2
9.1
10.4
9.6
8.8
10.8
Butter-fat
No. of sample
1
2
3
4
5
6
Carotene
(Y. U.)
per grm.
3.2
3.6
3.9
3.6
3.8
4.5
Vitamin-A
(B. U.)
per grm.
7.9
8.8
9.9
9.4
8.5
10.5
TABLE VI
Effect of storage on the carotene and vitamin-A contents of butter-fat kept in a
sterilised bottle sealed with paraffin wax
R. W. value . . .
Iodine value . . .
Carotene (Y. U.) . . .
Vitamin-A (B. U.) . .
Melted butter
Fresh
sample
24.3
35.6
2.4
4.2
One
month's
storage
24.2
35.8
2.1
3.8
Three
months'
storage
24.8
36.2
1.8
3.6
Six
months'
storage
23.8
37.6
1.2
2.8
260 Carotene and Vitamin-A Contents of butter-fat in cows
TABLE VII
Effect of clarification of butter-fats on their Reichert and Iodine values. The
table shows the changes observed during the clarification of the butter-fat
by heating at 50°C and 200°F in an air oven for half an hour.
Melted butter-fat (50°C)
No. of sample
1
2
3
4
5
6
7
8
9
10
R.W.
value
(Mean
of 2
values)
26.8
25.6
26.8
27.4
26.3
27.2
26.8
26.6
26.8
27.9
I. N.
(Mean of
2 values)
34.6
35.8
34.6
34.8
35.2
34.8
34.8
34.7
34.1
33.4
Clarified butter-fat (200°F)
No. of sample
1
2
3
4
5
6
7
8
9
10
R.W.
value
(Mean
of 2
values)
26.8
25.8
26.8
27.7
26.1
27.3
26.7
26.8
26.8
27.8
I. N.
(Mean of
2 values)
34.5
35.4
34.3
34.7
35.6
34.5
34.4
34.8
34.5
33.8
TABLE VIII
Effect of storage on the Reichert and Iodine values of butter-fats. They were
kept in sterilised bottles sealed with paraffin wax.
Name of sample
1
2
3
4
5
Values for fresh
sample
R.W.
(Mean
of 2
values)
24.2
25.6
27.8
27.8
29.9
I. N.
(Mean
of 2
values)
37.6
36.2
33.8
33.9
32.5
Values for stored sample
R. W. (Months)
1
24.4
25.5
27.6
27.7
29.8
2
24.4
25.2
26.8
27.6
29.4
6
24.1
25.5
25.8
27.9
28.8
12
23.6
24.4
23.2
26.8
27.2
I. N. (Months)
1
37.8
36.2
33.8
33.3
32.4
2
37.9
36.6
35.2
33.3
32.6
6
38.2
36.2
36.6
33.2
33.2
12
39.8
38.3
37.4
34.7
34.6
III—EFFECT OF FEEDING RED PALM OIL ON THE CHARACTERISTICS OF BUTTER
For this purpose, a healthy cow of the same breed as in experiment I
was used. Its body-weight was about 600 lb. and was four years old. The
period of lactation was two months and average milk-yield at the time of the