发酵核桃粕复合粉中乳酸菌保护剂的筛选

采用Plackett-Burman设计筛选试验，从谷氨酸钠、脱脂乳粉、海藻糖、麦芽糊精、蔗糖、阿拉伯胶、甘油7个因素中对发酵核桃粕复合粉乳酸菌的保护剂进行筛选，再采用最陡爬坡试验确定响应面的中心点，最后采用Box-Behnken试验对其进行优化。结果表明，经Plackett-Burman设计筛选后，对乳酸菌活菌率影响较突出的为海藻糖、脱脂乳粉、麦芽糊精；经响应面优化后最佳保护剂配比为海藻糖2.23%、脱脂乳粉2.50%、麦芽糊精2.77%，再经真空干燥制粉，活菌总数为9.71×108 CFU/mL，能最大限度保留乳酸菌的活菌数。

Screening of lactic acid bacteria protective agent for fermented walnut dregs composite powders

The lactic acid bacteria protective agents for fermented walnut dregs composite powders (sodium glutamate, defatted milk powder, trehalose, maltodextrin, sucrose, Arabic gum and glycerinum) were screened by Plackett-Burman design experiments, and then the central points of response surface experiments were determined by steepest ascent experiments. Finally, the factors were optimized by Box-Behnken experiments. The results showed that after the Plackett-Burman design screening, the parameters that most significantly influence the living bacteria rate of lactic acid bacteria were trehalose, skimmed milk powder and maltodextrin. The optimum ratios of protective agents were trehalose 2.23%, skimmed milk powder 2.50% and maltodextrin 2.77%. By vacuum drying and pulverizing, the total viable bacteria were 9.71×108 CFU/ml, which indicated the powder could keep the maximum viable count of lactic acid bacteria.