Based on the current industrial corn ethanol production process in China, the laboratory corn ethanol fermentation method was established by optimizing the main liquefaction process indexes (mixing DS (Dry Solid, dry matter concentration), liquefaction pH, liquefaction time, thermostable α-amylase dose, liquefaction temperature) and main SSF (simultaneous saccharification and fermentation process) process indexes (glucoamylase dose, yeast inoculum and fermentation temperature).Under the conditions of mixing DS 25%, liquefaction pH 5.6, liquefaction time 120 min, liquefaction temperature 88 ℃ and thermostable α-amylase dose 40 U/g, the reducing sugar content in liquefied mash was (11.65±0.03) g/100 g and the viscosity of liquefied mash was (91.2±2.8) mPa.s, which was consistent with actual industrial corn ethanol SSF production process.The SSF conditions were determined as follows:glucoamylase dosage 150 U/g, yeast inoculation amount 3%, fermentation temperature 32 ℃.Under these conditions, the alcohol fermentation process was stable, and the maximum standard deviation of CO2 mass loss was 0.38, accounting for only 2.96% of the corresponding CO2 average mass loss.In the fermented mature mash, the ethanol content was (12.58±0.04) g/100 mL, the fermentation efficiency was 97.71%, and the conversion rate of corn flour to ethanol was 2.425 t/t, which was consistent with the normal range of actual corn ethanol production of Chinese.Based on the actual production process, this method can provide data reference for the optimization of alcohol production process and the selection of raw materials.
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