R. KARNAD 357
to the milk before inoculating the culture. The results obtained are tabulated
in Table VII.
TABLE VII
(250 gm. of milk culture used for each distillation)
|
Culture |
Time |
Temp. °C. |
N/10 alkali |
|
Blank ....... |
72 |
37 |
5.6 |
|
Addition of 0 . 2 per cent citric acid . . |
72 |
37 |
5.6 |
|
Blank....... |
24 |
37 |
5.3 |
|
Addition of 0 . 2 per cent citric acid . . |
24 |
37 |
4.4 |
|
Addition of 0 . 3 per cent citric acid . . |
48 |
37 |
4.3 |
|
Addition of 0 . 4 per cent citric acid . . |
96 |
37 |
3.9 |
|
Addition of 0 . 2 per cent neutral sodium cit- |
120 |
30 |
5.2 |
Citric acid and citrates do not appreciably increase the volatile acid
content of the culture (Table VII). It is interesting to note, however, that
the volatile acidity is increased by the addition of yeast extract, and a mixture
of yeast extract and neutral sodium phosphate to the milk (Table VIII).
TABLE VIII
|
Culture |
Time |
Temp. °C. |
N/10 alkali |
|
Blank....... |
68 |
30 |
4.3 |
|
Addition of 10 per cent yeast extract |
68 |
30 |
10.9 |
|
Ditto |
92 |
30 |
14.4 |
|
Addition of 5 per cent yeast extract . |
68 |
37 |
4.6 |
|
Addition of 5 per cent of yeast extract plus |
68 |
37 |
5.7 |
|
Blank....... |
68 |
30 |
3.9 |
|
5 per cent yeast extract . . . . |
68 |
30 |
6.0 |
|
10 per cent „ .... |
68 |
30 |
6.2 |
|
15 per cent „ .... |
68 |
30 |
7.6 |
|
20 per cent „ .... |
68 |
30 |
8.2 |