Abstract:To reduce the cost and increase the efficiency of raw material utilization in the production of alcohol from cassava, various conditions in the alcoholic fermentation of this starchy tuber were examined. The optimal fermentation conditions were determined to be a liquefaction temperature of 95.0℃ and a liquefaction time of 70.0 min. Additionally, at the saccharification temperature of 60.0℃, the saccharification time was 40.0 min. Under these conditions, the highest alcohol yield reached 54.01%, with a cassava starch utilization rate of 89.25%. On the basis of these findings, the application of liquid wastes generated from the production of various enzymes (viz., glucoamylase and amylase) in cassava-based alcohol production was studied for the first time. Following the addition of liquid waste from glucoamylase production to the alcoholic fermentation process, 1320 mL of amylase and 316.8 mL of glucoamylase were saved per ton of alcohol produced, and the addition of nutrient salts, such as urea and magnesium sulfate, was no longer required. Meanwhile, the alcohol yield had increased by 54.64%. Therefore, the utilization of fresh glucoamylase and amylase in the alcoholic fermentation of cassava can be greatly reduced by using the waste liquids from enzyme production, and the need for nutrient salts can be reduced. Furthermore, given the same quantity of raw materials, the alcohol yield can also be effectively enhanced. This study not only highlights the effective utilization of waste resources from the enzyme production industry but also provides theoretical support for new ways in which efficiency in the cassava-based alcohol production industry can be developed.
