Studies on the Continuous Fermentation

Part 4. Effect of Submerged Mold Culture on Yield of Alcohol from Acid-Hydrolyzed Mashes

Abstract

In this paper, experiments were conducted chiefly to find the solution to the following problems, i.e., the cause of low alcohol yield and the role of submerged mold culture as a yield factor in fermentation of acid-hydrolyzed sweet potato mash. From all the relevant experimental evidences following facts were found.
The cause of low alcohol yield is due to the large quantities of unfermentable sugars produced secondarily during the acid hydrolysis.
The phenomenon that the addition of submerged mold culture as a fermentation supplement increasing the alcohol yield were illustrated as follows. The dextrins left in the mash hydrolyzed incompletely are converted into fermentable sugars by the saccharogenic amylase system contained in added mold culture and are fermented to alcohol. Therefore, in the case of complete acid hydrolysis, the addition of mold culture to the hydrolyzed mash does not give any effect on the alcohol yield of the fermentation.