嗜酸乳杆菌冻干保护剂及其直投式复合发酵剂的开发

为提高嗜酸乳杆菌冻干存活率和研发以嗜酸乳杆菌冻干菌粉为基础的直投式复合发酵剂,本研究以嗜酸乳杆菌为试验菌株,在单因素实验、析因实验和最陡爬坡实验的基础上采用响应面分析优化了嗜酸乳杆菌真空冷冻干燥的保护剂配方。优化后将嗜酸乳杆菌冻干菌粉与肉糖葡萄球菌冻干菌粉以一定质量比复合并应用于萨拉米香肠的制备中。结果表明,嗜酸乳杆菌最佳冻干保护剂(以11%脱脂乳为基础)配方为:海藻糖3.03 g/100 mL、甘油9.50 g/100 mL、谷氨酸钠3.50 g/100 mL,此条件下,嗜酸乳杆菌冻干存活率高达81.24%;嗜酸乳杆菌与肉糖葡萄球菌的冻干菌粉最佳比例为1:2,直投式复合发酵剂最佳接种量为10~8 cfu/g。与对照组相比,该直投式复合发酵剂生产的萨拉米香肠酸味柔和,色泽、硬度、弹性良好,总体接受度最高。

The Development of Lyoprotectant for Lactobacillus acidophilus and Derived Direct-Vat-Set Composite Culture

In order to improve the freeze-drying survival rate of Lactobacillus acidophilus and develop a freeze-dried Lactobacillus acidophilus-based direct-vat-set composite culture, this study used Lactobacillus acidophilus as the experimental strain. On the basis of single factor experiment, factorial experiment and steepest ascent experiment, the lyoprotectant formula for Lactobacillus acidophilus subjected to vacuum freeze-drying was optimized by response surface methodology. After optimization, freeze-dried Lactobacillus acidophilus and Staphylococcus aureus powders were compounded in a certain mass ratio and applied to the preparation of salami. The obtained results indicated that the optimal lyoprotectant formula for Lactobacillus acidophilus (based on 11% skim milk) was: trehalose 3.03 g/100 mL, glycerol 9.50 g/100 mL, sodium glutamate 3.50 g/100 mL. Under these conditions, the freeze-drying survival rate of Lactobacillus acidophilus was 81.24%. The optimal ratio of freeze-dried Lactobacillus acidophilus and Staphylococcus aureus powders was 1:2, and the optimal inoculum quantity for the direct-vat-set composite culture was 108 cfu/g. Compared with the control group, the salami produced using the direct-vat-set composite culture had a mild sour taste, and good color, hardness and elasticity, with the highest overall acceptance.