麦胚乳酸菌发酵饮品的工艺优化及品质分析

以麦胚为原料，利用复合乳酸菌发酵研制麦胚乳酸菌发酵饮品。以离心沉淀率为评价指标，优化稳定剂含量；采用单因素试验及正交试验，优化麦胚乳酸菌发酵饮品工艺条件，并测定其理化指标。结果表明，最佳稳定剂为羟丙基二淀粉磷酸酯0.5%、琼脂0.2%；最佳发酵工艺条件为嗜热链球菌（Streptococcus thermophiles）、保加利亚乳杆菌（Lactobacillus bulgaricus）、乳双歧杆菌（Bifidobacterium lactis）、鼠李糖乳杆菌（Lactobacillus rhamnosus）、植物乳杆菌（Lactobacillus plantarum）、嗜酸乳杆菌（Lactobacillus acidophilus）、干酪乳杆菌（Lactobacillus casei）按照配比1∶1∶1∶1∶1∶1∶1制备发酵剂，接种量0.03%，发酵时间24 h，发酵温度 42 ℃。在此最佳条件下，麦胚乳酸菌发酵饮品为乳酪色，质地黏稠，口感细腻，总蛋白3.53 g/100 g，总膳食纤维2.12 g/100 g，维生素E 1.28 mg/100 g，亚油酸669 mg/100 g，α-亚麻酸75.8 mg/100 g，乳酸活菌数2.1×109 CFU/mL。

Process optimization and quality of lactic acid bacteria fermented wheat germ beverage

Using wheat germ as raw material, fermented wheat germ beverage was prepared with compound lactic acid bacteria as fermentation starter. The content of stabilizer was optimized using centrifugation precipitation rate as evaluation index. The fermentation technology of lactic acid bacteria fermented wheat germ beverage was obtained by single factor and orthogonal experiments, and the physical and chemical indexes were determined. The results showed that the optimal stabilizer was hydroxyl propyldi starch phosphate 0.5% and agar 0.2%. The optimal fermentation conditions were as follows: Streptococcus thermophiles∶Lactobacillus bulgaricus∶Bifidobacterium lactis∶Lactobacillus rhamnosus∶Lactobacillus plantarum∶Lactobacillus acidophilus∶Lactobacillus casei =1∶1∶1∶1∶1∶1∶1, inoculum 0.03%, fermentation time 24 h and temperature 42 ℃. Under the optimum conditions, the fermented wheat germ beverage was cheese color, with viscous texture and delicate taste, the physical and chemical indexes and microbial indexes were total protein 3.53 g/100 g, total dietary fiber 2.12 g/100 g, vitamin E 1.28 mg/100 g, linoleic acid 669 mg/100 g, α-linolenic acid 75.8 mg/100 g, and viable lactic acid bacteria 2.1×109 CFU/ml.