检索结果-南通市图书馆

This study aimed to screen the yeast strains with high gas production speed and good freezing resistance and improve the sensory deterioration of raw dough caused by freezing. In this study， five yeast strains were isolated from old dough， and the freezing tolerance of the yeasts was evaluated in terms of growth curve， fermentation power， and survival after freezing. The effects of the isolated yeast and the commercial yeast agent on frozen dough were compared and analyzed by texture characteristics， volatile flavor components， and sensory measurement. Results showed that Y2 of the 5 strains had good frost resistance and gas production， and the dough with Y2 added had better chewability and hardness， which could maintain the texture of the product. Molecular biology identified Y2 as a strain of Saccharomyces cerevisiae， and the differences in sensory and flavor substances between Y2 and three commercially available yeast preparations of dough frozen under the same conditions were compared. The textural and organoleptic results showed that the freeze-tolerant yeast Y2 had an improved effect on the quality of dough after freezing， and was significantly better than the commercially available common yeast in terms of chewiness and organization. On the difference of volatile flavor components， 54 flavor components were detected in group Y2， including 14 alcohols， 13 aldehydes， 14 esters， 7 acids， 1 ketone， and 5 alkanes. Partial least squares discriminant analysis (PLS-DA) was used to analyze the relative contents of 21 kinds of aroma substances in each group of dough. According to the weight coefficient of variables (VIP≥1)， 11 major flavor contributing substances were screened. The key flavor components of the Y2 and S3 groups had some similarities， and the key flavor components were more abundant. Using the relative content to plot the heat map， the content of key flavor substances in Y2 was significantly higher than that of the other groups， and the application effec

关键词：冷冻面团酵母菌耐冻性能分离筛选挥发性风味物质

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