Optimization of composite protectant formulation for ice wine fermentation agents in Sichuan-tibet plateau by vacuum freeze spray drying

The saccharomyces cerevisiae isolated from the ice grape was prepared by vacuum freeze spray drying. The formulation of wall material was optimized by single factor and orthogonal experiments,and then the properties of the agent were analyzed. The results showed that the optimal protective agent formula were 5% glycerin,7% sucrose,11% skim milk powder and 15% maltodextrin and the viable count and the live bacteria rate were 10.34 CFU/g and 78.25%,respectively. Under the optimal conditions,these ice wine fermentation agents showed nice properties,such as higher heat resistance and low temperature stability,and their surfaces were smooth and flat. The agents could produce gas at 10 ℃ during fermentation and its fermentation performance was better than commercial wine saccharomyces cerevisiae.