Study On The Technology Of Soybean Milk Fermentation By Lactobacillus Rhamnosus And Lactobacillus Casei

With the development of soybean products study and the improvement of people's health consciousness, The study and development on functional soybean product will become heat issues and consume fashion in soybean products domain. soybean included all kinds of functional and nutritional components which benefits the health and the growth of Lactobacillus rhamnosus and Lactobacillus casei;furthermore, Lactobaccillus fermented soybean milk increased the amount of vitamin, which benefit the assimilation of protein, Ca2+, Fe2+ and vitamin. Lactobacillus rhamnosus and Lactobacillus casei as typical probiotics, their function of increasing the health have been admitted ,soybean products with probiotics had been a bioengineering products of 21 century. This paper was based on optimize and brewage a for soybean milk fermented medium; Studied on ferment characteristic of Lactobacillus rhamnosus and Lactobacillus casei in milk and soybean milk; Also studied on the technology of Lactobacillus rhamnosus and Lactobacillus casei single and mixed fermenting soybean milk; This paper still analysis and evaluate the quality of products and the stability. at storage.Lactobacillus rhamnosus and Lactobacillus casei with adversity-resistant and high activity, which were isolated from dairy products were taken as experiment strains. The fermentation period of Lactobaccillus rhamnosum and Lactobacillus casei in the milk at 37℃were both 5h, the viable cell numbers were 2.8×109cfu/mL and 4.5×109cfu/mL, acidity 77.6°T and 79.1°T pH 4.55 and 4.51. The comparison of fermentative character of Lactobaccillus rhamnosum and Lactobacillus casei in the soybean milk at 37℃were that the fermentation period were both 5h, the viable cell numbers were 1.1×109cfu/mL,1.4×109cfu/mL, acidity 71.3°T,73.5°T pH 4.59 and pH 4.57.The effect of addition concentration of milk and sucrose in soybean milk on fermented curd time, cell growth, sense and flavor of products were studied. The optimal addition concentration of milk and sucrose were determined as 20% and 7%.Inoculation ,the ration of strains, initial pH,fermented temperature,oxygen-resistant etc factors were studied on the effect of curd time, cell growth, acid metabolize, flavor and sense of product. On the basic of above, by orthogonal experiment optimizing the technology parameters of Lactobacillus rhamnosus and Lactobacillus casei single and mixed fermented soybean milk, seeing about the stability of storage product. The orthogonal experiment result of the fermentation technology about Lactobacillus rhamnosus fermenting in soybean milk were that inoculation 5% (5×107cfu/ml ) ,initial pH 7.0, fermented temperature 37℃. the fermentation period was 5h, the viable cell numbers reached 1.6×109cfu/mL, pH 4.5, acidity 79.6°T;The orthogonal experiment result of the fermentation technology about Lactobacillus casei fermenting in soybean milk were that inoculation 7% (7×107cfu/ml ) , initial pH 7.0, fermented temperature 37℃. the fermentation period was 4h50min, the viable cell numbers reached 2.3×109cfu/mL, pH 4.5, acidity 78.2°T; The orthogonal experiment result of the fermentation technology about mixed strains fermenting in soybean milk were that inoculation 5% (5×107cfu/ml ) , initial pH 7.0, ratio of the strains L1:L2=1:2, fermented temperature 37℃. the fermentation period was 5h, the viable cell numbers reached 4.2×109cfu/ml, pH 4.5, acidity 80.1°T.The quality of products was analyzed and evaluated initially. The result indicated: the product was milk white, compact organize state, sweet dainty, dairy flavor .The soybean yogurt integrated the character of color and luster, flavor, nutrition and health-care together in one body. The soybean yogurt contents soy isoflavone , but yoguat does not content soy isoflavone. the storage time of soybean milk yogurt was 21d stored at 4℃. This product integrated the character of color and luster, flavor, nutritional with health-care, developing a school of one's own.This study could provide a scientific basis for the industrial production of Lactobacillus rhamnosus and Lactobacillus casei single and mixed fermented soybean milk products. At the same time, it could provided new ideas and methods for the development of other multi-function probiotics soybean milk products .