NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
66
Methods of Preparation of Ghee
two ways, the decantation process and the boiling process. In the former process the
butter was maintained for about an hour at 100°C. in an electric oven when scum, fat and
butter-milk separated in three clear layers. The clear fat layer was separated and heated
to 110°C. for five minutes to remove the adhering moisture. In the latter process the butter
was heated on a low flame till all the moisture was driven off and filtered to remove casein
particles. Acidity, colour, flavour, peroxide value, [Wheeler, 1932], vitamin A and carotene
content of ghee were determined. The results are given in Table I.
TABLE I
Effect of time and temperature of souring on ghee
Incubation
period in hours
24°C.
8
12
18
24
36
48
30°C.
6
12
18
24
36
48
35°C.
6
12
18
24
36
48
40°C
6
12
18
24
36
48
Curd
acidity
0.65
0.97
1.00
1.00
1.3
1.64
0.75
0.98
1.1
1.2
1.6
2.6
0.76
1.6
1.7
1.9
2.0
2.7
0.94
1.3
1.7
2.3
2.4
2.8
Butter
acidity
0.11
0.17
0.17
0.18
0.12
0.22
0.13
0.14
0.19
0.19
0.19
0.21
0.11
0.11
0.14
0.16
0.20
0.22
0.16
0.19
0.14
0.23
0.23
0.28
Ghee (Boiling process—B
Decantation process—D)
Acidity
B 0.05
D 0.03
B 0.08
D 0.04
B 0.06
D 0.03
B 0.08
D 0.03
B 0.07
D 0.04
B 0.14
D 0.04
B 0.05
D 0.02
B 0.06
D 0.02
B 0.09
D 0.04
B 0.12
D 0.05
B 0.09
D 0.03
B 0.12
D 0.04
B 0.06
D 0.03
B 0.07
D 0.03
B 0.06
D 0.04
B 0.11
D 0.04
B 0.14
D 0.05
B 0.16
D 0.06
B 0.06
D 0.02
B 0.11
D 0.05
B 0.11
D 0.05
B 0.14
D 0.04
B 0.16
D 0.05
B 0.16
D 0.06
Peroxide
value*
0.16
0.20
0.13
0.28
0.14
0.16
0.16
0.17
0.05
0.13
0.07
0.15
0.17
0.23
0.18
0.28
0.16
0.20
0.17
0.21
0.15
0.24
0.16
0.29
0.15
0.20
0.17
0.21
0.16
0.23
0.14
0.19
0.15
0.22
0.16
0.21
0.14
0.21
0.18
0.20
0.17
0.20
0.18
0.37
0.17
0.21
0.13
0.20
Vitamin A
blue units
—
__
11.5
11.5
—
—
12.1
12.1
—
—
12.1
12.2
—
—
11.5
11.5
—
—
12.1
11.5
—
—
12.1
12.1
—
—
11.5
11.5
—
—
12.1
12.1
—
—
12.1
12.1
—
—
12.1
12.1
—
—
12.1
12.1
—
—
12.1
12.1
Carotene
yellow unite
—
—
2.75
2.75
—
—
3.3
3.0
—
—
2.75
2.2
—
—
2.75
2.2
—
__
3.3
3.0
—
—
2.75
2.2
—
—
—
2.75
2.2
—
—
3.3
3.3
—
—
2.75
2.75
—
—
2.2
2.2
—
—
3.3
3.3
—
__
2.75
2.2
Colour, flavour,
and texture
Fair
Mild
Fair
Mild
Good
Good
Good
Good
Fair
Fair
Fair
Fair
Fair
Mild
Fair
Mild
Good
Fair
Good
Good
Fair
Fair
Fair
Fair
Good
Fair
Good
Good
Good
Fair
Good
Good
Fair
Fair
Fair
Fair
Good
Mild
Good
Fair
Good
Good
Fair
Good
Fair
Fair
Faintly mouldy
Fair
68
Methods of Preparation of Ghee
TABLE II
Changes in ghee on storage
Storage of ghee in
months
December 1 ...
October 3 ...
July
6 ...
December 12 ...
December 1 ...
October
3 ...
July
6 ...
December 12 ...
December 1
...
October
3 ...
July
6 ...
December 12
...
December 1 ...
October
3
...
July
6 ...
December 12 ...
December 1 ...
October
3
...
July
6
...
December 12
...
Acidity (percentage of
oleic acid)
pH
Colour
Flavour
Texture
Carotene
Yellow
Red
Vi t
a mi n A
saponifiaction
Origia
Present
Allahabad Agricultural Institute (Cow and buffalo)
0.96
0.64
0.41
0.65
5.3
5.2
5.3
5.1
yellow
„
„
white
good
„
fair
off
granular
pasty
greasy
„
3.0
2.0
0.9
0.2
0.9
0.7
0.7
0.3
5.5
2.8
2.8
0.0
219
218
219
225
215
219
225
243
Shillong Government Farm (Cow)
0.31
0.16
0.55
0.77
5.3
5.2
5.3
5.2
yellow
„
light
„
fair
„
„
off
pasty
„
greasy
granular
4.5
4.5
4.5
—
0.8
2.0
2.0
—
0.9
5.5
2.8
0.0
212
215
215
214
216
223
231
212
Hosur Cattle Farm (Cow)
0.28
1.60
0.34
0.67
5.40
5.4
5.3
5.1
yellow
„
„
light
good
„
off
„
granular
„
„
pasty
3.6
3.4
3.0
1.7
1.0
0.9
0.7
0.6
6.1
5.0
3.3
0.6
—
—
225
226
229
225
229
218
Kirkee Agricultural College (Buffalo)
0.38
1.10
1.30
4.90
5.1
5.2
5.2
5.2
yellow
white
light
white
off
fair
off
off
granular
pasty
„
„
1.1
0.6
1.0
0.3
0.5
0.5
0.6
0.4
7.2
5.5
2.8
0.8
229
229
227
229
231
233
238
229
Porbunder (Buffalo)
1.50
0.50
0.30
2.30
5.2
5.4
5.1
5.2
white
„
„
„
off
„
„
„
granular
„
„
„
0.6
0.2
0.6
0.1
0.5
0.0
0.7
0.0
5.0
1.7
1.1
0.0
257
210
209
210
221
221
213
220
70
Methods
of Preparation of Ghee
TABLE III
Analytical constants of rancid ghee and free fatty acids
Sample
Ghee
Military con-
tractor
Bazaar
Military con-
tractor
Bazaar
Ghee
Military con-
tractor ...
Bazaar ...
Military con-
tractor
Bazaar
Acid value
9.9
28.4
Saponifi-
cation
value
227
229
Insoluble
acids
192
196
Soluble
acids
35
33
Lactic
acid
—
—
R. M.
24
25.3
P.V.
0.8
1.2
Free fatty acids of ghee expressed as mg. of potash in 100 gm. of ghee
...
...
...
...
...
...
6.6
22.5
3.0
6.6
1.2
2.9
2.7
3.8
0.4
0.4
Composition of the total acids of ghee and free fatty acids
...
...
84
86
16
14
0.05
0.13
12
12
0.4
0.6
Kirsohner
value
19.4
18.9
1.1
1.1
8
10
Free fatty acids expressed on the basis of total free fatty acids taken as 100
...
...
...
...
68
79
32
30
1.2
1.0
31
15
4.0
1.5
12
8
Iodine
value
25.3
26.6
2.6
5.4
24
25
58
41
An examination of Table III shows that the composition of the free fatty acids of high
acid ghee is different from that of the stock ghee of which it is a part and that lactic
and other acids produced during the souring process have passed from the water to the fat
phase in the clarification process. There is a large proportion of lower fatty acids and un-
saturated acids of the oleic type in the free fatty acids. Davies [1941] has also found that
oleic acid forms the largest proportion of the free fatty acids in stored butter. It is, there-
fore, clear that the glycerides of ghee are split in a selective way rather than uniformly during
the process of development of acidity on storage.
Neutralization of acidity in ghee. No study of acidity in ghee would be complete with-
out suggestion for reducing the free fatty acids of desi or country ghee. As the practice
stands to day, in hot areas and during summer months, there is bound to be a high free
fatty acid content in ghee. If the boiling process of clarification of butter into ghee be
replaced by the decantation process, the acidity will be reduced to one-third of the present
figure. Nonetheless the removal of acidity in ghee deserves equally careful attention and study.
The removal of free acids in oils and fats (edible or industrial) is a routine process in refineries
and in deodorization and hydrogenation plants; but the same has not been attempted by the
ghee trade. Besides, the removal of acids from ghee presents peculiar difficulties due to its
composition, that is, due to the presence of lower fatty acids and water-soluble acids, and due
to its fine flavour, colour and vitamins. The results obtained in this direction in a number
of trials are recorded. The absence of a ghee-grading station, or a large blending centre
prevented us from giving a large scale trial and determining the possibilities in this direction.
K. S. RANGAPPA AND B. N. BANNRJEE 71
About 10 lb. of bazaar ghee of acidity 4.3 per cent oleic acid were bought from the
market and used in the experiments. On a laboratory scale the choice of a proper alkali and
its strength were determined in the following way. Caustic soda 0.16 N, hot and cold,
16 N and 3.2 N, ammonia 0.1 N, hot and cold, 1.6 N, and 3.2 N, sodium carbonate 0.16 N,
hot and cold, 1.6 N, and 3.2 N, and caustic lime in saturated solution, paste and in cream
form were tried. The neutralizations were effected in the following manner:
(a) The calculated quantity of alkali was added in bulk, mixed and washed with hot
water.
(b) The calculated quantity of alkali was added in four to six instalments, mixed, washed
each time and finally the adhering soap was washed off.
(c) Ghee was first washed with hot water two or three times and then the acidity was
neutralized as in (b) above.
(d) The calculated quantity of alkali was added in bulk, and the whole maintained at
about 60° to 70°C. for about six hours, the soap run off and washed.
Ghee was washed with hot water at about 90°C., so that, on cooling during the process, the
temperature of the mass was not below 60°C. Due to emulsification it was found that there
was a residual acidity when the calculated quantity of alkali was added. An excess of alkali
over the calculated amount was always necessary to completely neutralize the acidity. The
results are given in a tabular (Table IV) form with the effect of the treatment on the colour,
flavour, and texture of ghee.
Variations in ghee on neutralization
Sample
Bangalore ...
do.
after
neutralization
Peshawar (S) ...
do.
after
neutralization
Peshawar (W) ...
do.
after
neutralization ...
Carotene
yellow
units
0.5
0.4
0.4
0.2
0.5
0.2
Vitamin A
1.0
0.6
1.2
0.6
1.1
0.6
R. M.
24.2
21.7
25.5
24.5
28.9
26.4
Sapopifica-
tion
value
223
212
230
217
230
220
Acidity (oleio
acid)
4.3
0.2
10.5
0.6
10.8
0.5
Peroxide
value
0.25
0.30
—
—
—
—
TABLE IV
Neutralization of ghee with different alkalies
Alkali
NaOH
0.16 N
1.6 N
3.2 N
Na 2 CO 2
0.1N
1 6N
3.2 N
NH 4 OH
Ca (OH) 2
NaOH
1.6 N in
alcoholic
solution
Original
acid ghee
Quality
Light, oily, granular
Light, fair, granular
Light, oily, pasty
...
Light, off, pasty
Light, fair, granular
Light, off, pasty
Residual
acidity
after neutralisa-
tion
0.7
0.4
0.9
0.7
0.4
0.9
Loss
8.5
6.5
9.5
8.0
—
—
Excess of alkali
needed for
complete
neutralization
(in percentage)
15
10
20
15
10
20
All the acid cannot be neutralized with 30 per cent. excees of alkali
LOSS
9.5
8.0
12
8.8
8.0
7.6
Emulsification quickly takes place when the alkali is used as 0.4 N solution or as cream of lime
Light, estery, granular
Dirty yellow, oily and acidic,
pasty
0.35
—
—
—
9
—
9.0
—
When alkali is added in bulk an emulsion forms. If it is then maintained in water bath and then wash-
ed, the loss is 15 per cent and excess alkali needed for complete neutralisation is 30 per cent.
74
Methods of Preparation of Ghee
Time of incuba-
tion hours
35°C.
6
12
18
24
48
40°C.
6
12
18
24
48
24°C.
8
12
24
48
40°C.
6
12
24
48
45°C.
6
12
24
48
24°C.
8
12
24
48
40°C.
6
12
24
48
45°C.
6
12
24
48
24°C.
8
12
24
48
Curd
Lactose
3.9
3.6
3.4
3.5
3.3
3.7
3.4
3.0
2.9
2.9
Acidity
0.97
1.40
1.40
1.50
1.60
1.10
1.50
1.50
1.50
1.60
Butter
acidity
0.11
0.12
0.17
0.17
0.18
0.14
0.17
0.14
0.13
0.13
Ghee acidity
Boiling
process
0.05
0.06
0.07
0.08
0.08
0.05
0.07
0.07
0.09
0.09
Decantation
process
0.02
0.03
0.02
0.03
0.03
0.02
0.02
0.03
0.03
0.04
Yield
92
91
92
91
89
93
94
93
92
91
Boiled for 5 minutes
Milk—lactose 5.2, acidity 0.1 and fat 5.2 per cent
4.9
4.1
3.0
2.3
0.40
0.6
0.9
1.3
—
—
—
—
—
—
—
—
0.02
0.05
0.05
0.04
Milk—lactose 5.0, acidity 0.12 and fat 6.3 per cent
4.4
3.9
3.4
2.5
0.33
1.30
1.80
1.90
—
—
—
—
—
—
—
—
0.03
0.04
0.03
0.05
82
82
94
93
81
95
92
91
Milk—lactose 4.6, acidity 0.1 and fat 5.6 per cent
4.4
3.5
2.8
2.7
0.4
1.4
1.8
1.9
—
—
—
—
—
—
—
—
0.02
0.03
0.04
0.04
87
90
92
88
Boiled for 10 minutes
Milk—lactose 5.2, acidity 0.1 and fat 5.2 per cent
4.9
4.3
3.2
2.5
0.4
0.8
1.0
1.4
—
—
—
—
—
—
—
—
0.03
0.04
0.04
0.05
84
92
96 94
Milk—lactose 5.0, acidity 0.12 and fat 6.3 percent
4.30
3.8
3.2
8.3
0.35
1.3
1.8
1.8
—
—
—
—
—
—
—
0.04
0.05
0.05
0.04
80
96
92
92
Milk—lactose 4.6, acidity 0.1 and fat 5.6 per cent
4.4
3.6
2.7
2.7
0.36
1.4
1.6
1.7
—
—
—
—
—
—
—
—
Evaporated 5 per cent
0.03
0.05
0.04
0.05
80
92
96
88
Milk—lactose 4.0, acidity 0.1 and fat 6.6 per cent
4.4
3.8
3.1
2.9
0.5
0.8
1.2
1.3
—
—
—
—
—
—
—
—
0.02
0.02
0.28
0.04
88
93
90
89
M. R. SRINIVASAN AND B. N. BANERJEE 75
Time of incuba-
tion hours
40°C.
6
12
24
48
45°C.
6
12
24
48
24°C.
8
12
24
48
40°C.
6
12
24
48
45°C.
6
12
24
48
Curd
Lactose
Acidity
Butter
acidity
Ghee acidity
Boiling
process
Decantation
process
Yield
Milk—lactose 4.6, acidity 0.13 and fat 7.3 per cent
3.9
3.5
3.0
2.5
0.87
1.10
1.4
1.40
—
—
—
—
—
—
—
—
0.03
0.03
0.03
0.03
87
89
87
87
Milk—lactose 4.6, acidity 0.13 and fat 7.3 per cent
3.5
3.1
3.1
3.0
0.90
1.40
1.50
1.5
—
—
—
—
—
—
—
0.03
0.03
0.36
0.04
86
88
90
88
Evaporated 10 per cent.
Milk—lactose 4 9, acidity 0.12 and fat 6.5 per cent
4.2
3.7
3.1
2.8
0.55
0.66
1.10
1.40
—
—
—
—
—
—
—
—
0.02
0.02
0.02
0.04
89
93
91
90
Milk—lactose 4.6, acidity 0.13 and fat 7.3 per cent
3.9
3.4
2.6
2.6
0.87
1.10
1.40
1.50
—
—
—
—
—
—
—
—
0.03
0.03
0.03
0.04
87
92
84
88
Milk—lactose 4.6, acidity 0.13 and fat 7.3 per cent
3.7
3.4
3.3
2.9
0.95
1.40
1.60
1.60
—
—
—
—
—
—
—
—
0.03
0.04
0.04
0.04
88
93
92
93
Conclusion. Processing of milk, previous to souring, by boiling for 10 minutes
or evaporating it till there was a reduction in volume by 5 per cent is perfectly satis-
factory. Compared to pasteurization, boiling process is far more efficient in reducing the
bacterial count.* It is effective and best suited to Indian village practice.
Milk processed by boiling soon after collection and seeded within two to three
hours produces curd of firm texture and satisfactory flavour. Only the 48 hour samples
of 40° and 45°0. temperature batches were slightly acidic in flavour and mouldy in ap-
pearance. The texture of ghee was uniformly firm and granular. The flavour was good
but mild in intensity. The colour of the six hour samples was lighter than the rest.
Vitamin A and carotene were not affected at all by the processing treatment of milk.
The storage property, i. e. the induction period, of ghee from milk soured for 48 hours
was slightly better than ghee from the six hour soured milk.
SEED CULTURE
Ghee is essentially clarified butterfat. It may be produced from country or creamery
butter. In the case of both, some form of souring takes place. Country butter is
most commonly obtained by churning whole milk, which has been allowed to sour, usu-
ally after the addition of a starter, that is, seed curd from the previous batch. After
souring the curd is churned into butter. Curd or dahi is also a popular food, and is
consumed alone or with rice, or wheat preparations, either salted or with sugar. It forms
the basis of a special type of lassi chas, or buttermilk, and may be consumed with ice,
salt or sugar to taste. Good dahi should have a creamy and smooth surface, free from
bubbles, while the cut surface should be trim and free from hole due to gas-forming
*cf. Marketing Report (1941) No. 23, 213 and Hunziker (1933) Butter Industry, 287.
M. R. SRINIVASAN AND B. N. BANERJEE 77
TABLE
III
Comparative study of different types of seed culture
(Temperature of incubation 40°C.)
Time of
incuba-
tion
(hours)
0
2
4
6
8
10
12
14
16
18
20
24
A (Laboratory curd)
pH
6.9
5.6
4.6
4.4
4.4
—
4.4
—
4.4
—
4.4
4.4
Acidity
0.04
0.24
0.57
0.71
—
1.3
—
1.4
—
1.5
1.5
Lactose
4.4
3.8
3.7
3.54
3.4
—
2.7
—
2.5
—
2.3
2.3
B (Village curd)
pH
6.9
6.0
4.8
4.4
—
—
4.4
—
4.4
—
4.4
4.4
Acidity
0.36
0.19
0 6
0.77
—
—
1.3
—
1.4
—
1.6
1.6
Lactose
4.4
3.8
2.8
—
—
2.3
—
2.1
—
2.0
1.9
C (Hotel curd)
pH
6.9
6.2
4.7
4.4
—
—
4.4
—
4.4
—
4.4
4.4
Acidity
0.04
0.20
0.54
0.75
—
—
1.11
—
1.3
—
1.5
1.6
Lactose
4.4
3.9
3.7
3.5
—
—
2.7
—
2.6
—
3.3
2.0
D ( Mess curd)
pH
6.5
5.6
4.8
—
4.4
—
4.4
—
4.4
—
4.4
4.4
Acidity
0.11
0.35
0.74
—
1.1
—
1.4
—
1.5
—
1.6
1.6
Lactose
4.4
3.8
3.7
—
3.4
—
2.7
—
2.5
—
2.3
2.3
E (Pure culture)
pH
6.4
—
6.3
6.1
5.9
5.4
4.7
4.4
4.4
4.4
4.4
—
Acidity
0.11
—
0.13
0.16
0.23
0.45
0.67
0.91
1.3
1.3
1.6
—
Lactose
4.37
—
4.35
4.3
4.2
4.0
3. 7
3.4
3.8
2.4
2.4
—
Seed curd
Acidity
A. 1.0
B. 0.72
C. 1.4
D. 0.51
Lactos
3.4
0.45
1.0
3.4
78
Methods of Preparation of Ghee
down other microflora and prevent putrefaction. Therefore the Indian fermented products
are of uncertain flavour and composition, quality, palatability, etc. In studying the souring
process of dahi for ghee manufacture, the changes taking place in the lactose content of milk
have been recorded together with other changes in a general way. Seed curd propagated in
the laboratory having a firm texture and sweet flavour has only been used in the amounts of
2.5 per cent by volume and with the acidity of 1 to 1.4 per cent, and lactose content of 3.5
per cent. Since the temperature at which souring is generally carried out varies within a wide
range, fermentation has been studied at a number of temperatures to include all the seasons
of the year. Souring has been carried on with a pure culture of Acidophilus lactobacillus
for comparison with that of a mixed flora seed curd. Results obtained from other studies in
souring have been borne in mind in drawing conclusions. (Refer to table in Part I; seed
curd tables and pure culture tables in Part II; acidity tables of village method of prepara.
tion of ghee in Part III.)
Experiment. Buffalo milk has been used for the experiments. The acidity of fresh milk
varied from 0.07 to 0.09 per cent lactic acid, lactose content between 4.4 and 4.8 per cent, and
pH 6.4 to 6.9. Half a litre of milk was sterilized for 60 minutes in steam, cooled down,
seeded with 2½ per cent of seed curd of firm texture and sweet flavour for souring studies.
Souring experiments were carried out at temperatures of 6°-8°C., and at 10°, 17°, 25°, 30°, 35°,
40° and 45°C. Samples were taken out at intervals of 2, 4, 6, 8, 12, 16, 18, 24, 36, and 48
hours. In the case of the cold temperature studies samples were taken up to 96 hours and
at longer intervals as the rate of souring was slow. The pH, lactose content, and acidity were
determined as before. Lactic acid was determined according to Friedman et al. [1930],
Well mixed curd 10 c. c. in quantity was diluted to 500 c. c. with distilled water and
warmed to 40°-50°C. when the casein coagulated in lumps. Then the solution was
filtered and 10 c. c. of the filtrate was extracted thrice with 30 c. c. of ether. Ether was
evaporated off from the combined ether extracts and the acid left behind was estimated by
oxidation to acetaldehyde and trapped in bisulphite solution. The results are given in
Tables, IV, V and VI.
TABLE IV
Souring with pure culture
Time of incubation
hours
33°C.
12
24
48
12
24
48
37°C.
12
24
48
12
24
48
Total acidity
Lactose
Lactic acid
Ratio of lactic to total
acid per cent
Pure culture
Milk—Lactose 1.7 and acidity 0.13
0.73
1.40
1.4
3.9
3.4
3.3
0.68
0.20
1.20
93
90
90
Laboratory seed curd
Milk— Lactose 4.7 and acidity 0.13
0.82
1.50
1.70
3.7
3.3
2.8
0.59
1.20
1.40
72
80
81
Pure culture
Milk—Lactose 4.9 and acidity 0.09
0.81
1.40
1.40
4.1
3.4
3.3
0.72
1.30
1.20
90
91
89
Laboratory seed curd
Milk—Lactose 4.9 and acidity 0.09
0.97
1.60
1.80
3.7
3.1
1.7
0.70
1.30
1.40
70
81
76
M. R. SRINIVASAN AND B. N. BANERJEE 79
TABLE V
Souring with seed curd
Time of
incubation
hours
7°C.
0
18
24
36
42
48
72
96
10°C.
0
18
36
42
48
60
72
96
17°C.
0
12
18
24
36
48
25°C.
0
3
6
9
12
15
18
24
36
48
30°C.
0
3
4
5
12
18
24
36
48
35°C.
0
1
2
3
4
6
12
18
24
36
48
Curd
Acidity
0.09
0.13
0.16
0.24
0.31
0.38
0.49
0.76
0.09
0.16
0.4
0.65
0.71
0.74
0.84
1.02
0.1
0.4
057
0.85
1.0
1.1
0.07
0.11
0.18
0.3
0.46
0.57
0.68
0.89
1.00
1.1
0.03
0.09
0.14
0.2
0.58
0.76
0.82
1.1
1.2
0.04
0.17
0.2
0.29
0.45
0.6
0.85
1.2
1.2
1.2
1.2
pH
6.7
6.3
6.2
5.9
5.8
5.6
5.4
5.1
6.7
6.2
5.6
52
5.1
5.0
4.8
4.8
6.7
5.8
5.5
5.2
5.0
4.8
6.6
6.3
6.0
5.6
5.2
5.0
4.9
4.6
4.4
4.4
6.9
6.1
5.9
5.5
4.4
4.4
4.4
4.4
4.4
6.8
6.2
6.1
5.3
5.2
4.4
4.4
4.4
4.4
4.4
4.4
Laotose
4.9
4.7
4.6
4.5
4.5
4.4
4.3
3.9
4.9
4.6
4.4
4.4
4.2
4.2
3.7
3.6
5.0
4.6
4.4
4.0
3.8
3.0
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Butter
Acidity
—
—
—
—
—
—
0.11
3.14
—
—
—
—
0.14
0.11
0.11
—
—
—
—
0.16
0.20
0.2
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Flavour
and
texture
—
—
—
—
—
—
pasty good
good
—
—
—
—
good
good
good
—
—
—
pasty good
good
good
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Ghee
Acidity
—
—
—
—
—
—
0.05
0.04
—
—
—
—
0.03
0.05
0.05
—
—
—
—
0.03
0.05
0.05
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
— —
—
—
—
—
—
—
—
—
Flavour
and
texture
—
—
—
—
—
—
good
fair
—
—
—
mild
good
good
—
—
—
—
mild
fair
fair
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
80
Methods
of Preparation of Ghee
TABLE V—contd.
Time of
incubation
hours
40°C.
0
1
2
3
4
6
10
12
18
24
Acidity
0.04
0.15
0.24
0.46
0.57
0.71
0.92
1.00
1.20
1.20
Curd
pH
6.8
6.1
5.6
5.0
4.6
4.4
4.4
4.4
4.4
4.4
Lactose
—
—
—
—
—
—
—
—
—
—
Butter
Acidity
—
—
—
—
—
—
—
—
—
—
Elavour.
and
texture
—
—
—
—
—
—
—
—
—
—
Ghee
Acidity
—
—
—
—
—
—
—
—
—
—
Flavour
and
texture
—
—
—
—
—
—
—
—
—
—
TABLE VI
Souring with seed curd
Time of incubation
hours
24°C.
8
12
18
24
48
45 C.
6
12
24
48
Curd
Lactose Acidity
Butter
acidity
Ghee
B—Boiling process
D—Decantation process
Acidity Peroxide
value*
Vitamin A Carotene
Flavour
and
texture
Yield
Milk—Lactose. 4.7, acidity 0.1 and fat 6.2
4.2
3.9
3.7
3.7
3.6
0.53
0.81
0.94
0.94
1.10
0.12
0.14
0.16
0.18
0.19
B 0.40
D 0.02
B 0.06
D 0.03
B 0.05
D 0.03
B 0.06
D 0.03
B 0.07
D 0.03
0.59
0.53
0.70
0.61
0.60
0.61
0.70
0.54
0.72
0.75
—
—
11.0
11.0
—
—
11.2
11.0
11.0
11.0
—
—
2.2
2.9
—
—
2.5
2.5
3.2
3.2
fair
fair
fair
fair
good
fair
good
good
good
good
95
94
95
95
93
Milk—Lactose 4.4 acidity, 0.14 and fat 7.0
3.1
2.6
2.5
2.5
1.18
1.50
1.60
1.60
0.14
0.18
0.18
0.22
B 0.05
D 0.02
B 0.06
D 0.03
B 0.08
D 0.03
B 0.09
D 0.03
0.61
0.57
0.62
0.67
0.77
0.57
0.74
0.86
—
—
11.0
11.0
11.5
11.0
11.0
11.0
—
—
2.2
2.0
2.2
2.2
2.5
2.5
fair
fair
good
good
good
good
good
good
89
91
90
87
*Millimole per Kg. of fat.
M. R.
SRINIVASAN
N
AND
B.
N.
BANERJEE
81
FIG. 1. Lactose-acidity in differing types of seed
FIG. 2. Lactose used and acidity developed at temperatures of 24°C., 30°C.
and 45°C. with mixed flora (seed curd)
Discussion. The H ion of the curd falls steadily with souring and stops at pH 4.4; there
it remains stationary, though the acidity goes on increasing with time. The acidity of curd
increases with the time of souring and the rate is higher as the temperature is higher. But
below 20°C. the rate of increase of acidity in curd slows down very much, so that at about
10°C. the souring process is very slow and requires artificial heating to complete the process
of curdling within reasonable limits of time. In cold winter days, therefore, it is the practice
in the Indian household to warm the souring vessel by keeping it near the kitchen fire. The
rise of acidity is regular up to about 1 per cent, and then it slows down. With pure culture
of Acidophilus lactobacillus the rise of acidity is up to 1.4 per cent, and then it stops. With
a mixed flora the rise in acidity does not stop but continues until half the lactose content of
milk is used up. By that time putrefaction sets in and the curd is unfit for consumption.
The ratio of lactic acidity to total acidity is unity up to 0.6 per cent acidity of the curd, and
thereafter it makes up about 90 per cent in the case of pure cultures, 80 per cent in the case
82
Methods of Preparaiion of Ghee
of good seed curd, and less with a mixed flora [Suzuki, Hastings and Hart, 1910]. Lactic
acidity does not rise more than 1.25 per cent with pure cultures, and 1.4 per cent with mixed
flora. This is shown graphically in Fig. 1, 2, 3, 4.
FIG. 3. Acidity and time
FIG. 4. Lactose acidity with L. B. Acidophilus as inocculum
at temperatures of 40°C, and 33°C.
The rise in acidity and lactose loss in curd is a measure of the nature of the souring
process. The resultant butter on churning carries with it the products of souring, the
acidity, flavour, texture, etc. The texture of the curd (slimy, ropy, uniformly firm) determines
the quality of the curd and of the butter. The presence or absence of gas bubbles or cracks
in the mass of the curd denotes the activity of gas-forming bacteria. A sweet aromatic
flavour indicates a good souring process and its absence the activity of undesirable microflora.
Acidity of butter from properly soured curd is about 0.2 per cent lactic acid or less. Any
rise in acidity above this figure indicates unsatisfactory souring and lipolysis of butterfat.