黄酒酵母发酵过程中产尿素的变化规律研究

Study on the Changes of Urea Content during the Yeast Fermeantion for Yellow Rice Wine Production

摘要:

本论文采用二乙酰肟比色法测定了黄酒酵母发酵过程中产尿素的规律。结果显示：黄酒酵母在生长过程中，分泌大量尿素到胞外，在稳定期（培养第51 h）胞外尿素浓度达38.642 mg/L，胞内尿素浓度（培养第27 h）为6.043 mg/L。培养基初始pH3,4时，相对初始pH=5而言酵母细胞的尿素的胞外分泌较少；培养基酒精浓度为12%时，酵母胞外尿素分泌水平下降；培养温度升高胞外尿素分泌水平下降。酶制剂代替麦曲的黄酒发酵实验结果显示，发酵液中尿素含量水平随着发酵进程而升高。

Abstract:

Urea content was detected with two acetyl monoxime colorimetric method in this paper. The results showed that a large number of urea was extracellular secreted by rice wine yeast during the growth. In the stable phase (cultured for 51 hours), extracellular urea concentration was up 38.642 mg/L and intracellular urea concentration (cultured for 27 hours) was 6.043 mg/L. Extracellular urea secretion of yellow rice wine yeast in the medium with initial pH 3, or 4, was relatively less than that in the medium with initial the pH 5. The urea secretion levels were decreased when Huangjiu yeast were cultured in the medium with 12% of alcohol, being lower than that with 4% or 8% of alcohol. Extracellular urea secretion levels were increased when the culture temperature increased from 28 ℃ to 32 ℃. The enzyme preparations instead of wheat koji fermentation experiment showed that the level of urea content in the fermentation increased with the fermentation process.