木薯酒精浓醪发酵液化糖化工艺的研究

目的]优化木薯粉浓醪酒精发酵中液化糖化的工艺条件。方法]以木薯粉为原料进行浓醪酒精发酵,在单因素试验的基础上,运用正交试验对液化糖化工艺中的各种参数进行了研究。结果]正交试验表明,各因素的影响主次为:糖化酶量>糖化时间>糖化pH值>糖化温度。根据各因素的水平K值大小,确定了木薯粉浓醪酒精发酵中最佳液化工艺条件,即:料水比为1∶2.3,液化温度105℃,液化酶用量为10 U/g木薯粉,液化时间为2 h;最佳糖化工艺条件为:糖化pH值4.5,60℃时加入糖化酶150 U/g木薯粉后,直接将醪液冷却至33℃进行发酵,即糖化与发酵同时进行。在该条件下进行木薯粉浓醪酒精发酵,酒精终浓度可达16.9%(V/V)。结论]该研究为后续发酵条件的优化以及100 L的放大试验打下了基础。

Study on Liquefaction and Saccharification Technology in High-gravity Alcohol Fermentation on Cassava Meal

Objective] The study aimed to optimize the technological conditions of liquefaction and saccharification during the high-gravity alcohol fermentation on the cassava meal.Method] The cassava meal was taken as the raw material for high-gravity alcohol fermentation.Based on single factor experiments,the various parameters in technological conditions of liquefaction and saccharification were studied via orthogonal experiments.Result] The orthogonal experiments showed that the effects of various factors in order were the dosage of liquefaction enzyme>saccharification time>saccharification pH>saccharification temperature.According the K value of each factor the optimum conditions for liquefaction in the high-gravity alcohol fermentation on the cassava meal were confirmed as follows: the cassava-water ratio was 1∶2.3,the dosage of liquefaction enzyme was 10 U/g and the liquefaction processed at 105 ℃ for 2 h.The optimum conditions for saccharification were as follows: the saccharification pH was 4.5,the enzyme was added at 60 ℃ with dosage of 150 U/g cassava meal,and then the fermentation broth was cooled to 33 ℃ for fermentation without delay,namely the saccharification and fermentation were conducted simultaneously.Under these conditions,the final alcohol concentration reached 16.9%(V/V).Conclusion] This study laid the foundation for the optimization of the subsequent fermentation conditions and the 100 L scale-up test