Abstract
1. Comparative studies were carried out on fermentable sugar production in secondary phase of starch hydrolysis with six mold enzyme solution (mold bran extracts of Aspergillus oryzae, Asp. usamii, Asp. awamori, Rhizopus tonkinensis, and α-amylase added extracts of Asp. usamii and Rhiz. tonkinensis), in the presence and absence of yeast.
2. It was concluded that the initial velocity of glucose formation from starch, referred here as “Glucose-Direct” activity(8) (G. D.) represents the amount of saccharogenic amylase (Table 1).
3. Generally speaking, as has been described by PAN et all (17, 18, 22), transglucosidation of mal-tose into unfermentable oligosaccharides plays an important role upon the rate of fermentable sugar formation from starch with the solution of those mold enzymes. Without yeast, the effect of the action continues to appear up to the secondary phase of hydrolysis. In the presence of yeast, the effect disappeares rather fast on account of the reconversion of the presynthesized unfermentable oligosaccharides into fermentable sugars by the rapid yeast removal of maltose and the reversibility of transglucosidase. This makes the difference between the two curves, Ta (total fermentable sugars produced in the absence of yeast) arid Tp, (total fermentable sugars produced in the presence of yeast). It however, is not always as vivid as in Fig. 2., because the degree of the transglu-cosidation reaction is different in each enzyme solution, due to their different transglucosidase activity and their different value of D/G. D. (ratio of α-amylase to saccharogenic amylase).
4. It was concluded that the “Glucose-Direct” activity shows close correlation to the velocity of starch attenuation in the presence of yeast.
