Method for preparing local brewer's yeast dry powder

Abstract

The invention discloses a method for preparing local brewer's yeast dry powder. The method comprises the following steps: separating and screening local brewer's yeast strains from self-produced medium temperature Daqu with the combination of conventional plate separation and a brewer's yeast fingerprint spectrum method, selecting a high-quality local brewer's yeast strain, and culturing a seed liquid in a yeast leach powder peptone glucose agar culture medium; inoculating the cultured seed liquid into a fermentation tank, carrying out amplification culture, collecting a local yeast fermentation liquid after culturing, centrifuging the local yeast fermentation liquid by using a high-speed freeze centrifuge, and collecting a local yeast concentrated mother liquid; putting a protector into the local yeast concentrated mother liquid, and carrying out freeze drying, thereby obtaining dry powder. The yeast count of the local brewer's yeast dry powder prepared according to the method is up to 7 billion/gram of dry powder, and the survival rate is 90% or higher; as the freeze drying protector has the main component of trehalose, the freeze drying protector has very stable chemical properties in addition to a magic protection function on microorganisms, and rotting and deterioration of fermented grains are not resulted.

Description

technical field [0001] The invention relates to the field of preparation of Saccharomyces cerevisiae dry powder, in particular to a preparation method of local Saccharomyces cerevisiae dry powder. Background technique [0002] Saccharomyces cerevisiae is a model strain of Saccharomyces yeast, which is widely used in liquor, wine and other yeast strains. The use of Saccharomyces cerevisiae can significantly improve the wine yield. However, most of the active dry yeast used in the liquor industry are commercial strains, not yeast strains in the local environment. Long-term use of commercial yeast will destroy the microbial ecology in the fermentation environment balance, resulting in an imbalance in the proportion of microorganisms, which in turn affects the quality of wine. In order to improve the series of problems caused by the addition of commercial yeast, it is urgent to screen a dominant strain of S. While the yield rate can also balance the ecological environment, it i...

AI Technical Summary

Problems solved by technology

The use of Saccharomyces cerevisiae can significantly improve the wine yield. However, most of the active dry yeast used in the liquor industry are commercial strains, not yeast strains in the local environment. Long-term use of commercial yeast will destroy the microbial ecology in the fermentation environment balance, resulting in an imbalance in the proportion of microorganisms, which in turn affects the quality of wine. In order to improve the series of problems caused by the addition of commercial yeast, it is urgent to screen a dominant strain of S. While the yield rate can also balance the ecological environment, it is the coordination and interaction between microorganisms to improve product quality

[0003] At present, there are three main ways to use Saccharomyces cerevisiae in wine production. One is to add directly to the fermented grains after fermentation in liquid culture. However, the number of yeast cultured in this way is low and the water is large, which cannot well meet the requirements of production. requirements

The second way is to prepare yeast bran koji for use. The number of yeasts in the finished yeast koji can reach 2 billion to 3 billion / g. Although the quantity can meet the production demand, the preparation process of yeast bran koji is relatively complicated, and the use of bran Koji will increase the porosity of the fermented grains, which will affect the brewing process to a certain extent

The cryoprotectants usually used in the preparation of dry powder preparations mainly include skimmed milk powder, sucrose, animal serum, dimethyl sulfoxide, etc. These cryoprotectants are easy to cause spoilage or have certain toxicity, and cannot be directly used in the food industry.