东北酸菜发酵酵母菌冻干保护剂的优化研究

利用响应面分析法优化东北酸菜发酵异常汉逊酵母菌（Hansenula anormala）的冷冻干燥保护剂配方。以异常汉逊酵母菌体存活率为评价指标，通过Plackett-Burman设计法筛选出脱脂乳、海藻糖和木寡糖3个显著因素，采用最陡爬坡试验确定3因素的水平并作为响应面优化试验的中心点，利用Box-Behnken优化设计试验建立异常汉逊酵母菌体存活率与3个因素之间的回归方程，通过响应面分析各个因素对响应值的效应关系。结果表明，最佳保护剂各组分为脱脂乳21.8 g/100 mL，海藻糖11.6 g/100 mL，木寡糖0.6 g/100 mL。在此优化条件下，预测的菌体存活率为82.20%。应用优化保护剂进行3次重复冻干试验，菌体冻干存活率的平均实际值为82.11%，与预测值基本相符，表明该模型具有应用意义。

Optimization of freeze-drying protective agent for yeast from fermented Northeast pickle

The formulation of freeze-drying protective agent for Hansenula anomala from fermented Northeast pickle was optimized by using response surface methodology.Using the yeast survival rate as evaluation index,three significant factors including skim milk powder,trehalose and xylo-oligosaccharide was screened by Plackett-Burman tests.Through the steepest ascent test,the level of three factors was determined and the central point of response surface optimization tests.The regression equation between the yeast survival rate and three factors was established by Box-Behnken optimization tests design,and the response surface method was used to analyze the effect of each factor on the response value.The results shown that the optimal protective agent for the yeast starter was skimmilk powder 21.8 g/100 ml,trehalose 11.6 g/100 ml,and xylo-oligosaccharide 0.6 g/100 ml,under the conditition,the yeast survival rate of lyophilizing was up to 82.20%.Three repeated freeze-drying experiments were carried out with the optimized ratio,results showed that the average survival rate of lyophilized yeast was 82.11%,which was basically consistent with the predicted value,indicating that the model had practical significance.