Illustration: In the examination of a sample 26.048 grams of midzu ame in 100 cubic centimeters were polarized in a 200 millimeter tube and the following data were obtained:
Polarization of sample in angular degrees 69°.06, which is equal to an apparent gyrodynat of 132.6:
Total reducing sugar as dextrose 33.33 per cent:
Polarization in angular degrees after fermentation 30°.84 = [a]D = 59.2.
Substituting these values in the several equations gives the following numbers:
- (1) 0.3333 = d + 0.62m
- (2) 132.6 = 53d + 138m + 193dʹ
- (3) 59.2 = 193dʹ
- (4) 73.4 = 53d + 138m
- (5) 55.74 = 105.14m
- (6) m = 0.5301 = 53.01 per cent.
- (7) d = 3333 - 3286 = 0.0047 = 00.47 per cent.
- (8) dʹ = 59.2 ÷ 193 = 0.3067 = 30.67 ” ”
| Percentage | of | dextrin | 30.67 | per | cent. |
| ” | ” | maltose | 53.01 | ” | ” |
| ” | ” | dextrose | 00.47 | ” | ” |
| ” | ” | water | 14.61 | ” | ” |
| ” | ” | ash | 00.31 | ” | ” |
| Sum | 99.07 | ” | ” | ||
| Undetermined | 0.93 | ” | ” |
For polarization the lamplight shadow polariscope employed for sugar may be used, and the degrees of the sugar (ventzke) scale converted into angular degrees by multiplying by 0.3467.
The process of fermentation is conducted as described in the paragraph given further on, relating to the determination of lactose in the presence of sucrose.