| 摘要 |
PURPOSE: To select a yeast having useful as a material for producing beer, liquors, breads, etc., in fermentation or brewing industry and having high activity in high accuracy by evaluating activity of the yeast usingα,α-trehalose content in yeast cell as an index. CONSTITUTION: Beer yeast is cultured in wort at 6-8 deg.C until stationary period and the beer yeast is recovered and washed with water and stored in cold water (4-10 deg.C). Yeasts having different activities are prepared by changing storage day and pH in these yeast cells and the content ofα,α-trehalose expressed by the formula are measured. As a result, it is found that trehalose content in yeast cell is decreased and pH in the cell is rapidly decrease since the trehalose content is reduced to 0.5-1.0wt.% base on dried weight and reaches pH5.8 which is a turning point at which brewing activity is rapidly lowered and a yeast having high activity for producing beer, liquors, bread, etc., in fermentation or brewing industry is selected in high accuracy by evaluating activity of yeast usingα,α-trehalose content in the yeast cell as a index.
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