蔗糖汁高糖发酵条件及糖代谢研究

以高浓度蔗糖汁(锤度大于25°BX)为培养基，以耐酒精、耐高糖的酿酒酵母为菌种，对发酵条件即发酵液初始糖锤度、发酵温度、发酵液初始pH值、接种量进行单因素和正交试验优化。结果表明：在锤度30°BX、pH4.5、温度30℃、接种量10%的最佳发酵条件下，发酵终液酒精体积分数可达19.02%，远高于普通发酵(10%～15%)。并在最佳发酵条件下，对糖代谢情况进行初步研究。结果表明：在发酵过程中，锤度为30°BX时，酒精体积分数最大，且糖分完全利用，35°BX时，果糖无法被完全利用，40°BX时，葡萄糖和果糖都无法被完全利用；发酵液中糖分的渗透压与时间成负线性关系，且下降速率与初始糖锤度成线性负相关。

Fermentation Conditions and Sugar Metabolism of High-sugar Cane Juice

In this study, the fermentation conditions of high-sugar (＞ 25 °BX) cane juice with a yeast strain having good resistance to alcohol and sugar were optimized by one-factor-at-a-time and orthogonal array design methods for maximizing alcohol production. The results indicate that the alcohol content in fermentation broth at the end of fermentation was up to 19.02% under the following optimal conditions: initial brix of fermentation liquor of 30 °BX, fermentation pH of 4.5, fermentation temperature of 30 ℃ and inoculation amount of 10%, which was much higher than that obtained by ordinary fermentation (10%－15%). Sugar utilization was also investigated at different brix levels during the fermentation process. When the brix was 30°BX, sugars could be fully utilized. However, fructose could not be utilized at the brix level of 35°BX. Moreover, neither fructose nor glucose could be utilized at the brix level of 40°BX. In fermentation broth, the osmotic pressure of sugars had a negative linear relationship with fermentation time and a negative linear relationship between sugar consumption rate and initial brix level was also observed.