Development of microencapsulated yogurt with Lactobacillus plantarum and Lactobacillus acidophilus
Using fresh milk as raw material,microencapsulation yoghurt was produced with addition of Lactobacillus plantarum and Lactobacillus aci-dophilus.Using acidity,viscosity,pH and sensory score of the product as evaluation indicators,the yogurt process technology were comprehensively analyzed through single factor,orthogonal experiments and principal component analysis(PCA).The survival rate of lactic acid bacteria in microen-capsulated yogurt through in vitro simulated gastrointestinal fluid experiments were explored.The results showed that the optimal technology of the yogurt was using fresh milk as raw material,fermentation starter 0.2%,sugar 8%,pectin 0.2%,microcapsule 2%,fermentation temperature 41 ℃,and time 9 h.Under the optimized condition,the yogurt had fine texture,uniform tissue state,and the sensory score was 85,and its viscosity,acidity,pH were 410 mPa·s,137 °T and 5.2,respectively,and physicochemical indexes and microbial indexes met the national standard.The results of in vitro simulation experiments indicated that the survival rate of yogurt made by adding lactic acid bacteria microencapsulation reached 67.60%and 62.00%,after treated with gastric and intestinal fluids,which increased 36.21%and 33.94%,respectively.Lactic acid bacteria microcapsules added to yogurt provided a reference basis for the development of new yogurt foods.