Study on fermentation process of Saccharomyces cerevisiae immobilized by persimmon tannin gel

Objective:To compare the free Saccharomyces cerevisiae and immobilized Saccharomyces cerevisiae with persimmon tannin gel and immobilized Saccharomyces cerevisiae within PVA-sodium alginate and obtain a optimal set of parameters for wort fermentation with Saccharomyces cerevisiae embedded with persimmon tannin gel. Methods:Extract persimmon tannin from persimmon and mix it with crosslinking agent. Then embed Saccharomyces cerevisiae and use immobilized Saccharomyces cerevisiae with persimmon tannin gel for formentation. On the basis of single factor experiment, through the orthogonal experiment to study the effects of different parameters such as temperature, immobilized rate, p H, and initial sugar degree to the fermentation properties of immobilized Saccharomyces cerevisiae. Results:Compared with other materials the real fermentation rate of the immobilized Saccharomyces cerevisiae with persimmon tannin gel achieved 96.05%, which was the maximum value. The best fermentation conditions were as follows:immobilizing quantity 10, initial sugar degree14%, p H4 and fermentation temperature 30℃.Under the optimal conditions, the real fermentation rate achieved97.2%.Conclusion:The conditions of persimmon tannin gel preparation were mild, it increased the activity of embeded Saccharomyces cerevisiae and provided a possibility for the wide use of this materials.