Study On The Fermentation Process Of Tremella Yogort By Lactobacillus

This paper mainly discussed the development of tremella yogurt with lactobacillus fermentation,which took tremella as raw material, the preparation of tremella juice need crushing, soaking, grinding pulp filtration, added the right amount of skim milk powder, using lactic acid bacteria fermentation, the developed tremella fermented yogurt both have tremella unique flavor and contains tremella polysaccharide component. In order to contain as much as possible tremella nutrients, especially the temella polysaccharide,in the fermentation product, the test discussed the technological conditions of the tremella juice preparation; The white fungus juice and milk ingredients varied, this experiment has carried on the domestication of lactic acid bacteria to make lactic acid bacteria adapt the environment of tremella juice; At the same time, in order to make the flavor, taste and state of the yogurt well, it had carried on the tremella yogurt fermentation process parameters test, stabilizer test, ripening test.The results were as follows.1. The white fungus contained abundant polysaccharides, with good health care function, in order to make tremella polysaccharide as far as possible in the juice extracted, first has carried on the single factor experiment, we could know that the preparation of tremella juice had a close relationship to extraction temperature, extraction time and the solid-liquid ratio.To this end, on the extraction temperature, extraction time, the solid-liquid ratio to design the L9(34) orthogonal experiment was carried out, found in the extraction temperature of100℃, extraction time of90minutes, the solid-liquid ratio of1:200, the yield of polysaccharides could reach the highest, it is18.35g/100g, at the same time was also the most suitable for fermentation.2. By single factor test shows that:tremella juice lactic acid fermentation mainly ralated to the quantity of milk powder, fermentation temperature,the lactobacillus inoculum size,the added amount of sucrose, for this designed the four factors and three levels orthogonal test,the test results showed that:the quantity of milk powder was8%, the inoculum size was6%, the fermentation temperature was41℃, and the added amount of sucrose was9%,they were the best fermentation conditions, thus the white fungus fermentation yogurt, palate soft and smooth, tasted delicious, curd was solid and uniform,nice texture. Ripening could make product flavor even better, for this designed the ripening tests, determined the best ripening conditions: ripening at0～4℃for24h,the yogurt had a rich aromatic flavor, tasted the best.3. The using of the stabilizing agent in the yoghurt was to increase viscosity, prevented the whey separation, and improved its texture, state and taste. Through the single factor test choosed three colloid:xanthan gum, sodium alginate,gelatin, due to the single stabilizer effect was not obvious, with composite stabilizer. The L9(34) orthogonal test show that adding xanthan gum0.08%, sodium alginate0.04%, gelatin0.02%in the tremella juice, the stability of white fungus fermented yoghurt was good.4. Homogeneous was an essential part of the fermentation process,and could make the various components of the fermentation base fluid uniform blend together. For this designed homogeneous test,the result showed that:under70℃,25Mpa homogeneous2times, the fermentation product could achieve best state.