NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
STUDIES ON SOME FACTORS AFFECTING THE
PHYSICAL AND CHEMICAL CONSTANTS
OF GHEE
BY
N. S. DOCTOR, M.Sc., A.I.I.Sc., AND B. N. BANERJEE, M.SC.
(Department of Biochemistry, Indian Institute of Science, Bangalore)
AND
ZAL R. KOTHAVALLA, B. AG. ANI. HUS. (BOM.), B.SC. AGRI. (EDIN.),
N.D.D. (SCOT.)
(Imperial Dairy Institute, Bangalore)
(Received for publication on 27 November 1939)
G HEE forms one of the main items of our Indian dietary and the importance
of this product can be judged from the fact that about 55 per cent of the
total milk produced in India (690 million pounds) is used for making ghee
[Wright, 1937]. Generally, the solidity, grain structure, colour, taste and
aroma form the criteria of quality in ghee. But the introduction of the present
day oil and fat refining and hydrogenation processes in preparing artificially
blended ghee substitutes has greatly discounted the value of these properties.
This, together with the wide natural variation of the physical and chemical
constants of ghee, has brought the food analyst into the uncomfortable and
unscientific position of having to fix limits of variation in dealing with ghee.
The interpretation of results of analysis in such cases is unsatisfactory and
in the absence of reliable evidence for distinguishing genuine from adulterated
ghee by means of physical and chemical constants, this state of affairs will
continue. Accordingly, in 1937 the Central Government of India (Rept.
Ghee Conference, Agriculture and Marketing in India, Sept. 1937, p. 5) fixed
certain specific standards for the grading of cow and buffalo ghee, to check
the malpractice of adulteration of ghee and the sale of artificially blended
products under the name of genuine ghee.
Strong objections were raised from various quarters against the above
standards of grading as an all-India standard since analytical constants for
ghee are variable and depend on such factors as food, breed, lactation period,
care and treatment of the animal, seasonal variations and methods of prepa-
ration of ghee. The analytical constants of ghee are variable. They,
however, vary only within certain limits except in some abnormal cases.
It was therefore necessary to study the effect of various factors on the range
of variation of the physical and chemical constants of ghee.
In the present investigation the effect of the method of preparation of
ghee, the breed and the food of the animal on the physical and chemical
constants of ghee have been investigated with the view to studying the range
of variation of these constants,
63
N. S. DOCTOR, B. N. BANERJEE AND Z. R. KOTHAVALLA 65
The sample of butter prepared after 24 hours' souring was stored in an
open glass vessel just as is done in practice. Samples were taken out at the
end of 11 and 15 days' storage and melted into ghee and analysed (samples
5 and 6). The butter progressively lost flavour, developed patches of mould
and acquired an undesirable flavour during storage. Butter which had
been stored for 15 days was melted into ghee by the boiling-off method and
analysed (sample 7). The results are given in Table I.
TABLE I
The cream process butter fat
Sample No.
1
2
3
4
5
6
7
Reicliert value
33.0
31.3
31.2
31.2
31.0
31.1
31.0
Polensko value
1.9
1.9
1.8
1.8
1.8
1.7
1.8
Saponification value
238
239
239
238
238
239
239
The indigenous process curd after 24 hours' souring was churned into
butter (paddle churn) and analysed. Butter prepared by the curd process
was deeper in colour than that from the cream process and possessed a richer
and characteristic flavour. Immediately after preparation a portion of
butter was melted into ghee (decantation process) and analysed (A). This
sample was also stored in the same manner as the cream process butter and
samples were taken at the end of 2, 4, 7 and 15 days (B, C, D and F). Samples
of butter after 7 (E) and 15 (G) days' storage were clarified into ghee by the
boiling off method and analysed. This butter on storage deteriorated in
flavour much quicker than the creamery butter. The results are given in
Table II.
TABLE II
The curd process butter fat
Sample No.
A
B
C
D
E
F
G
Reicliert value
31.7
31.1
30.6
31.1
31.1
30.8
30.6
Polensko value
1.8
2.0
1.9
1.7
1.7
1.7
1.7
Saponification value
238
239
239
238
239
239
239
66 Factors affecting Physical & Chemical Constants of Ghee
The results show that there is no appreciable change in Reichert, Polenske
and saponification values of ghee prepared by different methods and condi-
tions. The Reichert value of fresh milk ghee is slightly higher than that of
sour-cream or curd-process ghee.
Curd-process butter and ghee were found to be richer in colour and
flavour than cream-process butter and ghee. Again curd-process ghee was
firmer in texture than cream-process ghee. Ghee prepared by the decantation
method compared with the boiling-off method of clarification of butter into
ghee, was firmer in texture. The flavour of curd butter disappeared more
quickly than that of creamery butter. Taken as a whole, however, curd
(desi) process ghee was better in flavour, colour and texture than cream
(dairy) process ghee. Soured milk or soured cream ghee is better than un¬
soured milk or cream ghee.
In the clarification of butter into ghee, when the moisture is removed
either by the decantation method or by the boiling-off method, the Reichert
value is not affected. There is no significant decrease in Reichert value on
storage for 15 days in the form of butter before clarification. Prepared
in a clean and proper way, very little lipolytic changes take place in the
souring process during storage as butter in both the cream and curd processes
of ghee manufacture. However, it cannot be said to apply in all cases as
Imperial Dairy Institute milk is very rich in carotenes, vitamins and other
natural anti-oxidants ; the average temperature at Bangalore is also only
22°C.
It may be concluded, therefore, that if the ghee be prepared hygienically
from the milk, the method of preparation has no appreciable effect on its
chemical constants.
EFFECT OF BREED ON CHEMICAL AND PHYSICAL CONSTANTS OF GHEE
This investigation was conducted under controlled conditions with the
milk of four breeds of cows, viz. Ayrshire, Cross-bred, Sindhi and Gir, and
with that of the Murrah buffalo. The animals were maintained at the Imperial
Dairy Institute Farm, Bangalore, under similar conditions of feeding manage-
ment. As the Ayrshire stock available at the Farm was limited, two animals of
each breed only were selected for the experiment. All animals were kept
on the same ration for four weeks before the experimental samples were
collected.
Six lots of butter from the milk of each breed were prepared under con-
trolled conditions at intervals of a week and the butterfats were immediately
analysed.
Sampling of butterfat.—All butter samples were melted in an air oven
at 105°C until the aqueous layer settled under a clear uniform layer of fat.
The aqueous layer was removed with a pipette and the liquid fat filtered
while still hot through cotton wool to remove scum. The fat was heated
carefully (temperature not exceeding 110°C), for about 5 to 10 minutes to
remove the last traces of moisture. All samples were bottled in brown glass
stoppered bottles and stored at — 4°C.
These samples of butter and butterfat were examined for melting point,
refractive index, and vitamin A and carotene contents. The melting point
68 Factors affecting Physical & Chemical Constants of Ghee
TABLE III
Breed Variation and Constants of Ghee
Ayrshire
Sample 1
2
3
4
5
6
Cross-bred
Sample 1
2
3
4
5
6
Moisture per cent
15.1
15.3
14.0
18.3
17.6
14.1
15.2
14.8
15.3
14.9
15.1
14.7
Butter
Fat per cent
84.5
84.3
85.4
81.2
82.0
85.6
84.5
84.8
84.3
84.7
84.6
85.0
Curd per cent
0.4
0.4
0.6
0.5
0.4
0.3
0.3
0.4
0.4
0.4
0.3
0.3
M. P. 0°C.
36.2
36.0
35.8
36.2
36.0
36.0
36.2
36.6
36.4
36.4
36.2
36.2
R.
Index at 40°C.
1.4558
1.4558
1.4558
1.4558
1.4558
1.4558
1.4555
1.4555
1.4555
1.4555
1.4555
1.4555
B. R. reading at
40°C.
45.0
44.5
Reichert value
23.6
23.2
23.0
23.3
23.4
23.2
26.0
26.0
26.2
26.5
26.2
26.1
Butter Fat
Polenske value
2.0
1.9
2.0
2.0
2.0
1.9
2.0
2.0
2.0
2.2
2.0
2.1
Kirscliner value
19.2
19.0
19.0
19.1
19.1
19.2
21.5
21.2
20.0
21.6
21.0
21.0
Saponification
value.
220
220
221
220
220
222
224
225
225
225
224
225
Iodine value
39.0
39.2
39.6
39.4
39.2
39.2
38.6
38.5
38.0
38.2
38.4
38.3
Percentage of free
fatty acids cal-
culated as oleic
acid.
0.50
0.60
0.36
0.60
0.50
0.54
0.62
0.67
0.82
0.71
0.60
0.72
Carotene mg. per
100 gm.
0.83
0.80
0.76
0.73
0.75
0.76
0.66
0.62
0.68
0.70
0.60
0.64
Vitamin A. B.V.
per gm.
19.8
19.6
18.8
19.0
18.7
19.5
18.8
18.2
18.0
18.8
17.8
17.6
N. S. DOCTOR, B. N. BANERJEE AND Z. R. KOTHAVALLA 69
Sindhi
Sample 1
2
3
4
5
6
Gir
Sample 1
2
3
4
5
6
Murrah buffalo
Sample 1
2
3
4
5
6
15.6
14.9
15.1
16.7
14.0
13.2
15.8
14.9
14.2
18.3
16.4
15.1
14.3
13.9
14.7
13.5
13.2
12.6
84.0
84.8
84.6
82.8
85.6
86.4
83.9
84.7
85.3
81.2
83.4
84.6
85.4
85.9
85.0
86.2
86.8
87.1
0.4
0.3
0.3
0.5
0.4
0.4
0.3
0.4
0.5
0.5
0.2
0.3
0.3
0.2
0.3
0.3
0.2
0.3
37.0
37.2
37.2
37.4
37.2
37.0
36.0
36.2
36.4
36.2
36.2
36.2
36.8
37.0
370
36.8
37.0
37.0
1.4556
1.4556
1.4556
1.4556
1.4556
1.4556
1.4553
1.4553
1.4553
1.4553
1.4553
1.4553
1.4549
1.4549
1.4549
1.4549
1.4549
1.4549
44.6
44.1
43.6
25.6
26.0
26.4
25.8
25.6
26.0
26.8
27.0
27.4
28.0
27.8
28.2
30.4
30.6
30.8
31.0
30.2
30.4
2.3
2.2
2.2
2.3
2.3
2.3
2.2
2.2
2.3
2.3
2.3
2.3
1.5
1.5
1.5
1.5
1.5
1.5
20.0
20.2
20.3
20.0
20.0
20.0
21.6
22.0
22.0
22.2
22.0
22.4
26.7
26.7
26.7
26.8
26.6
26.6
225
223
225
223
223
224
227
227
227
227
227
226
231
232
232
232
231
231
39.0
39.1
39.0
39.0
38.8
38.8
39.3
38.9
39.0
39.2
39.2
39.0
31.5
30.8
31.0
31.4
31.2
31.4
0.91
0.90
0.83
0.85
0.83
0.92
0.35
0.40
0.42
0.37
0.34
0.48
0.80
0.70
0.65
0.52
0.67
0.50
0.52
0.50
0.48
0.52
0.46
0.48
0.48
0.40
0.38
0.48
0.38
0.33
0.05
005
0.05
0.05
0.05
0.05
16.4
15.0
15.8
16.0
15.6
15.2
16.0
15.4
150
15.2
14.8
14.6
14.0
14.8
14.2
14.0
14.6
14.2
K
70 Factors affecting Physical & Chemical Constants of Ghee
Mixture before commencing the experimental feeding :—
Wheat bran . . .
Groundnut cake . . .
Gingili cake . . .
Bengal gram crushed
.
.
.
Gram husk . . .
per cent
36
18
18
10
18
100
One pound of the mixture was allowed for every two pounds of milk
produced. During the experimental period this mixture was replaced by
wheat bran and oil cake only.
The five groups were fed on groundnut cake, gingili cake, linseed cake,
cotton seed and coconut cake respectively in addition to wheat bran, ragi
straw, and Rhodes and guinea grass. The concentrate mixture was made up
by adding the respective oil cakes and wheat bran in equal quantities and
one pound of the mixture was allowed for every two pounds of milk produced.
The change to the new food was made gradually. The quantities of concen-
trates fed to each animal are given in Table IV. The cakes and cotton seed
were crushed and soaked in water with wheat bran and salt for about eight
hours before feeding. Milking was done by hand and twice daily. The
following time table gives more detailed information of the treatment of the
cows :—
(1) 3-30 a.m. to 4 a.m.
(2) 4 a.m. to 5 a.m. .
(3) 5 a.m. to 6 a.m. .
(4) 6 a.m. to 10 a.m.
(5) 10 a.m. to 2-30 p.m. .
(6) 3-30 p.m. to 4 p.m.
(7) 4 p.m. to 5 p.m.
(8) 5 p.m. to 3-30 a.m.
. Feeding half concentrates.
. Milking.
. Rest.
. Grazing.
. Rest and feeding half roughages.
. Feeding half concentrates.
. Milking.
. Rest and feeding half roughages.
TABLE IV
Quantities in pounds of concentrates fed daily
Cow No.*
Wheat bran . .
Oil feed . .
TOTAL lb.
Group I
251
7.5
7.5
275
5.50
5.5
Groundnut cake .
15.0
11.0
Group II
279
5.5
5.5
291
5.75
5.75
Gingili cake
110
11.50
Group III
280
5.0
5.0
290
4.75
4.75
Linsced cake
10.0
9.50
Group IV
265
4.50
4.50
270
5.75
5.75
Cottonseed
9.0
11.50
Group V
289
4.75
4.75
294
4.25
4.25
Cocoanut cake
9.50
8.50
Preparation of samples of butter.—Samples of uncoloured and unsalted
butter were made from the milk produced by each group under experiment
on three occasions, viz. (1) before commencing the experimental feeding
to represent controls, (2) at the end of 10-day feeding period and (3) at
the end of 20-day feeding period. Milk was separated immediately after pro-
duction and the fresh cream converted into butter. Ghee samples were pre-
pared by the decantation method and analysed.
*Cows calved between 14-9-38 and 1-1-39. Condition good.
N. S. DOCTOR, B. N. BANERJEE AND Z. R. KOTHAVALLA 71
The milk of each animal at eack milking was weighed and recorded but
for the purpose of simplicity daily average milk yields for each period are
given in Table V(a). Composite samples of milk were taken for determination
of butter fat and the data collected are given in Table V (b). The body
weight of each animal before and at the end of each period, are recorded in
Table V (c).
The cows took readily to the changed feed. They maintained their live
weight but they did not appear as lively and active during the experimental
period as before the experiment. Although the milk yields in all cases fell
considerably, there was no increase in fat percentage.
TABLE V (a)
Milk yield
Groups
Herd No. of cow
Control Daily yield
average
After 10 days oil feed-
ing Daily average
(1st period)
After 20 days Daily
average (2nd period)
I
251
lb. oz.
29 0
24 0
23 0
275
lb. oz.
21 0
18 4
18 6
II
279
lb. oz.
21 0
19 12
19 13
291
lb. oz.
23 0
22 12
22 0
III
280
lb. oz.
20 0
16 15
13 7
290
lb. oz.
19 0
16 8
10 8
IV
265
lb. oz.
16 0
15 3
14 3
270
lb. oz.
23 0
19 9
17 15
V
289
lb. oz.
18 0
14 3
13 10
294
lb. oz
16 0
13 10
13
TABLE V (b)
Average percentage of fat
Groups
Herd No. of cow
Control
1st period
2nd period
I
251
4.80
4.80
4.30
275
4.90
4.80
4.80
II
279
4.80
4.70
4.30
291
4.40
4.50
4.10
III
280
4.70
4.40
4.20
290
4.85
4.90
4.90
IV
265
4.90
5.00
4.60
270
4.90
5.00
5.10
V
289
4.60
4.70
4.20
294
5.00
5.50
5.70
TABLE V (c)
Body weight
Herd No. of cow
Control
1st period
2nd period
251
lb.
724
699
723
275
lb.
740
723
737
279
lb.
666
683
685
291
lb.
780
735
751
280
lb.
592
572
603
290
lb.
698
700
702
265
lb.
773
776
800
270
lb.
650
651
652
289
lb.
713
702
710
294
lb.
686
690
696
72 Factors affecting Physical & Chemical Constants of Ghee
Quality of butter and ghee after 20 days oil feeding :—
TABLE VI (a)
Judging of the butter samples
Herd No. of
Cow
251
275
GROUP I
279
291
GROUP II
280
290
GROUP III
265
270
GROUP IV
289
294
GROUP V
Oil cake
Groundnut cake
Gingili cake
Linseed cake
Cotton seed
Coconut oil cake
Outward appearance
Satisfactory rather light in
colour
Not very attractive, colour
lighter than in Group I
Very satisfactory colour and
shade darker than No. I
Quite satisfactory,
shade
approaching ideal butter
colour
Quite attractive, colour same
as No. IV
Body
Medium hard
Soft and soggy
Hard
Quite firm (harder than
No. III)
Hard, same as No. III
Texture
Good
Butter drawing into pin
heads when broken
Good grain showing sepa-
rately
Very satisfactory grains
small and prominent
Satisfactory grains rather
small but well set and
prominent
Flavour
Appetizing with slight oily
smell
Foreign to normal butter
Not so marked with little
indication of linseed oil
Appetizing and nutty, absence
of cotton seed smell
Very attractive, perhaps the
best sample.
Remarks
Place
IV
V
III
II
I
N. S. DOCTOR, B. N. BANERJEE AND Z. R. KOTHAVALLA 73
TABLE VI (b)
Judging of ghee samples
Group I
Group II
Group III
Group IV
Group V
Body
Satisfactory, medium hard
soft and leaky
Very soft and leaky
Quite firm
Quite attractive and hard
Texture
Good
Oily
Oily
Very satisfac-
tory grains
Satisfactory
grains smaller
than in IV
Colour
Fair yellow
Same as in I
Lighter than in
II
Fair yellow
Ditto
Flavour
Satisfactory ghee flavour
Ditto
Giving out indication of
linseed oil
Good ghee flavour
Giving out indication of
coconut oil
Re-
marks
Place
II
III
V
I
IV
The grading order of the butters was not retained when they were melted
into ghee. Group No. V was placed first in butter judging but, when melted,
gave a coconut oil flavour. The marked effect of feeding oil cakes can be
observed in Group III. The melting point was the lowest in the case of
Group III. Groups IV and V showed remarkable firmness in body and texture.
The average of the results of various determinations for each sample
of butterfat are given in Table VII.
TABLE VII
Dil cakes feeding and constants of ghee
I. Groundnut Cake
Control
1st period
2nd period
II. Gingili Cake
Control
1st period
2nd period
III. Linseed cake
Control
1st period
2nd period
IV.. Cotton seed
Control
1st period
2nd period
V. Coconut cake
Control
1st period
2nd period
R. Index at 40°C
1.4540
1.4540
1.4559
1.4540
1.4550
1.4556
1.4542
1.4552
1.4560
1.4550
1.4550
1.4550
1.4550
1.4532
1.4531
B. R. reading at 40°C.
42.3
43.7
45.0
42.3
43.7
44.6
42.6
44.0
45.2
43.7
43.7
43.7
43.7
41.1
41.0
Reichert value
30.0
25.2
25.8
26.0
26.9
26.1
29.1
24.9
24.6
25.9
25.1
23.6
26.9
26.5
26.5
Polenske value
2.3
2.0
2.1
2.5
2.4
2.2
2.4
2.4
2.1
2.3
2.0
2.1
2.5
2.9
3.0
Kirschner value
23.3
17.0
17.2
21.1
20.5
20.6
22.9
18.4
18.2
21.0
20.0
18.1
22.0
22.0
22.0
Saponification value
229
223
224
224
224
224
227
220
217
224
221
219
225
230
230
Iodine value (Wij's)
36.0
42.2
37.0
36.1
42.3
40.1
37.7
39.0
42.1
34.0
37.2
37.3
36.3
28.3
26.8
Percentage of free fatty
acids
calculated as
oleic acid
0.14
0.28
0.30
0.42
0.24
0.32
0.50
0.30
0.41
0 . 44
0.28
0.35
0.24
0.50
0.42
Percentage of moisture
less than
0.1%
„
„ „
„
„
„
„
„
„
„
„
„
„
Carotene in mg. per 100
gm.
0.52
0.36
0.41
0.38
0.41
0.41
0 .52
0.31
0.27
0.41
0.31
0.40
0.41
0.38
0.36
Vitamin A in B. V. per
gm.
16.4
11.1
11.0
15.3 12.3
11.4
16.2 9.0
8.3
15.0
12.4
12.0
15.0 11.0
10.9
74 Factors affecting Physical & Chemical Constants of Ghee
After 20 days of oil-cake feeding all animals returned to their original
ration as given before the experiment. Milk yield was found to return to the
previous figure. For comparison, another experiment was performed wherein
oil cakes from the concentrates mixture were replaced by carbohydrate foods
and green grass. The animals of the first group were selected and fifteen days
after the end of the previous experiment the following ration was given at
the rate of 1 lb. for every 2 lb. of milk produced.
Wheat bran
Wheat crashed
40 per cent
20 per cent
Oats crushed
Barley
20 per cent
20 per cent
In addition to the concentrates each cow was given 10 lb. of lucerene and
1 oz. of salt. Roughage (guinea grass) and water were allowed in ad lib.
Milking, preparation of butter and ghee, and the determination of physical and
chemical constants were done in the same manner as in the previous experi-
ment.
Milk yield
Cow No.
Control Daily average
After 10 days Daily average
After 20 days Daily average
251
25.5 lb.
24.3 „
21.9 „
275
20
lb.
17.7 „
16.2 „
Fat percentage
Control
1st period
2nd period
4.5
4.5
4.6
4.2
4.5
4.7
The cows were found to be in a healthy condition and were constant in
body weight. Although the milk yield showed a slight fall, the fat content
was constant and tending rather to increase.
Samples of butter were prepared from the composite samples of milk
of two animals at two periods. The butter was very attractive in body and
colour and was quite hard and of good texture. It was the best as compared
with those of the oil feeding experiments. The ghee was of a deep yellow
colour, good granular texture, quite firm and of satisfactory flavour. The
results of the determination of the chemical and physical constants are given
in Table VIII.
N. S. DOCTOR, B. N. BANERJEE AND Z. R. KOTHAVALLA 75
TABLE VIII
Constants of ghee—Oil cakes replaced by carbohydratefood and green grass
—
Moisture
........
Refractive index at 40°C
B. R. Reading at 40°C
Reichert value
.......
Polenske value
.......
Kirschner value
.......
Saponification value
......
Iodine value (Wij's)
......
Percentage of free fatty acid calculated as oleic acid
Carotene mg./100 gm.
......
Vitamin A in B. V. per gm.
....
Control
1st
period
2nd
period
less than 0.1 per cent
1.4540
42.3
30.0
2.5
23.3
229
30.0
0.14
0.52
16.4
1.4531
41.0
29.1
2.9
23.2
230
29.5
0.21
0.60
18.4
1.4524
40.0
29.1
2.9
23.3
230.0
29.8
0.30
0.61
18.8
DISCUSSION
In the feeding experiments, the food is arranged according to the usual
practice obtaining in the country. Thus cotton seed alone is fed as such in
crushed form, while other oil seeds are fed as cakes after the oil has been
pressed out. In the case of the Imperial Dairy Institute herd, it is not possible
to carry on such experiments for any length of time as it was found that it
upset the milk yield and other records of the animals. The animals selected
for the experiment were all healthy and receiving balanced rations except
for the oil cakes. In this experiment great care was taken to minimise the
errors due to seasonal variations and stage of lactation as the composition of
the butterfat, mostly as regards the lower fatty acids and the amount of
unsaturated acids, is influenced by the variation in breed, food, seasonal
variations, and stage of lactation.
The results obtained indicate that when liberal amounts of oil cakes
are fed to cows, the butterfat shows a definite increase in unsaturated acids
(iodine value) except in the case of feeding coconut cake. Channon, Drummond
and Golding [1924] have reported that the effect of coconut oil, which bears
some similarity in composition to butterfat, was not very marked but that the
effect due to feeding cod liver and arachis oil was more pronounced. The
feeding of arachis oil gave butterfat showing analytical values resembling