Growth Activity of Liquid Yeast Culture from Raisin Solution by RSM

摘要

The study was performed using a three-level,three-factor experiment design,and aimed at determining the optimum combinations of incubation temperature (X1; 15,25,35 ℃),proportion of water in the raisin solution (X2; 100,300,500 mL),and percentage of sugar (X3; 0,20,40％) on the responses of the changes of the (1) pH value,(2) titratable acidity,(3) alcohol content,(4) lactic acid bacteria count,and (5) yeast count on 3 or 6 days.At the third day after incubation,the result showed that the maximum yeast counts was observed with 20％ sugar treatment under 25 ℃,and the yeast counts could be improved with increasing the proportion of water in the raisin solution.On the other hand,at the 6th day after incubation,the optimum result showed 20％ sugar was supplied to yeast,and the optimum proportion of water in the raisin solution was 100～ 300 mL under 25 ℃.However,the proportion of water in the raisin solution was increasing to 500 mL,the optimum condition was 30％ 30％ sugar under 30 ℃,the sugar should be exhausted from raisin,yeast require additional sugar as carbon source for their growth.