浩乳德用直投式发酵剂保护剂配方优化及应用

以植物乳杆菌（Lactobacillus plantarum）686为试验菌株，以甘油、山梨醇、脱脂乳、葡萄糖、菊粉、海藻糖、谷氨酸钠和谷胱甘肽为保护剂，以冻干存活率为评价指标，通过单因素试验及响应面试验优化发酵剂保护剂配方，用直投式（DVS）发酵剂制作浩乳德（奶豆腐），并对其品质进行评价。结果表明，菌株686最佳保护剂配方为脱脂乳添加量12.5 g/100 mL、海藻糖添加量6.0 g/100 mL及谷氨酸钠添加量12.5 g/100 mL。在此优化配方条件下，菌株冻干存活率为81.59%。扫描电镜（SEM）观察结果表明，添加最优冻干保护剂的乳酸菌686完整无破碎，用其制作浩乳德的理化指标、鲜味及丰富度均有极大改善。

Formula optimization and application of Directed-Vat-Set protective agent for Haorude

Using Lactobacillus plantarum 686 as test strain, glycerol, sorbitol, degreased milk, glucose, inulin, trehalose, sodium glutamate and glutathione as protective agents, and freeze-drying survival rates as evaluation index, the formula of the starter protective agent was optimized by single factor and response surface experiments. Haorude (dried milk cake) was prepared with Directed-Vat-Set (DVS), and its quality was evaluated. The results showed that the optimal formula of protective agent for strain 686 was obtained as follows: degreased milk 12.5 g/100 ml, trehalose 6.0 g/100 ml and sodium glutamate 12.5 g/100 ml. Under the optimized formula conditions, the freeze-drying survival rate of the strain was 81.59%. The observation result of scanning electron microscope (SEM) showed that the cell of L. plantarum 686 added with the optimal freeze-drying protective agent was intact. The physicochemical indexes, umami and richness of Haorude made with the strain 686 were greatly improved.