冷冻面团中酵母抗冻保护剂的优选

为改善冷冻面团品质，减少低温对酵母的损害，对常见的几种酵母抗冻保护剂进行配方优化。单因素试验测定冷冻7 d后酵母存活率和面团发酵力，筛选出保护剂及其添加量水平，再运用二次回归正交旋转组合设计进行优选试验，在对存活率影响试验中，因素主次顺序为：海藻糖＞甘油＞脯氨酸；在对发酵力影响试验中，因素主次顺序为：海藻糖＞脯氨酸＞甘油。验证得到最优试验条件为：海藻糖、甘油和脯氨酸添加量分别为2.23%、3.43%和1.55%。在此条件下，酵母存活率和面团发酵力分别为85.86%和322 mL。

Optimization of antifreeze protectant of yeast in the frozen dough

For improving the quality of frozen dough and reducing the damage to the yeast at low temperature, the formula of several common yeast antifreeze protectants were optimized. The yeast survival rate and fermentation capacity was detected after freezing for 7 d, the protectants and addition was screened by single factor experiments, and the optimal formula was determined by quadratic orthogonal rotating design. Results showed that the factors influencing yeast survival rate in order was trehalose, glycerol, proline trehalose; and the factors influencing fermentation capacity in order was trehalose, proline and glycerol. The optimal formula of protective agents was trehalose 2.23%, glycerol 3.43% and proline 1.55%. Under this condition, the survival rate of the yeast was 85.86% and the fermentation capacity of the yeast was 322 ml.