Alcohol fermentation of sweet potato. Membrane reactor in enzymatic hydrolysis

Use of Ultrafiltration membrane systems in stirred cell and in thin‐Channel systems for immobilizing enzyme (sweet potato intrinsic and β‐amylase) in hydrolysis of sweet potato through a continuous operation mode were studied. Both the filtration rate and reducing sugars, produced as the result of enzymatic hydrolysis, decreased with the filtration time. The immobilized enzymes in the thin‐channel system showed a much better performance compared to that in the stirred cell system. Addition of crystalline sweet potato β‐amylase to the sweet potato increased both the filtration rate and reducing‐sugars content. Alcoholic fermentation of the filtrate resulted in an alcohol content of 4.2%. This represented fermentation of 95% of the sugars with an efficiency of 88%.