大豆多肽对酵母细胞增殖及耐冻性的影响

Influence of Soy Peptides on Yeast Cells' Proliferation and Tolerance to Freeze-thaw Stress

酵母细胞的活性和耐冻融性对于发酵制品和冷冻面团技术具有十分重要的影响。将大豆多肽、酪蛋白胨、酵母氮源三种不同的氮源加入培养基培养酵母细胞,通过对生长曲线、细胞湿重、面团发酵和冷冻后面团发酵及细胞存活率的比较,评价大豆多肽对酵母细胞活性及耐冻能力的影响。结果表明,随着培养基中大豆多肽量的增加,所得的酵母细胞生物量增加,添加量超过25 g/L以后,酵母细胞生物量不再有明显增加,25 g/L是大豆多肽的最适添加量。与相同量的其他氮源相比,大豆多肽作为培养基氮源得到的酵母细胞在冷冻后存活率更高,其发酵面团仍能够保持较好的发酵力。大豆多肽能够促进酵母细胞增殖、增强酵母细胞的耐冻性、提高面团的发酵效果。

Yeast cells’ activity and tolerance to freeze-thaw stress has an important influence on fermen-ted products and frozen-dough technology. Soy peptides, casein peptone, and yeast nitrogen base were used as different yeast medium nitrogen sources to culture yeast cells. The effects of soy peptide on yeast cells’ activity and the tolerance to freeze-thaw stress were evaluated based on the growth curves, survival rates after freezing, cell wet weights, and dough fermentation. The results showed that the more soy pep-tides were added, the more yeast biomass was obtained, which did not increase when soy peptides reached 25 g/L or higher. Therefore, the optimum amount of soy peptides was 25 g/L. Yeast cells had a higher survival rate when they were incubated in media containing soy peptides, and the corresponding dough also retained better fermenting capability after freeze-thaw steps. Compared with other nitrogen sources, soy peptides increased the cell biomass and improved the cell tolerance to freeze-thaw stress and the fermentation effect.