茶多酚对乳酸菌发酵及酸奶品质的影响

Effect of tea polyphenols on fermentation of lactic acid bacteria and yogurt quality

为了研究茶多酚对乳酸菌及酸奶品质的影响,将鲜牛乳以每个样品100 m L为标准分装于玻璃瓶中,每16个玻璃瓶为一组,共9组,测定了酸奶的滴定酸度、持水力、质构、乳酸菌活菌数、感官评价等指标。结果表明:茶多酚对乳酸菌生长繁殖的影响呈抛物线形,茶多酚添加量低于0.30%时对乳酸菌有明显的促生长作用(P<0.01),茶多酚添加量为0.20%时促生长作用达到最佳;同时对乳酸菌产酸有一定抑制作用,可延长酸奶的保质期;随着茶多酚添加量的增加,酸奶的持水力及质构的测定结果及感官评价均呈抛物线形变化,在茶多酚添加量为0.20%时各项指标达最优。说明当茶多酚添加量为0.20%时,茶多酚对乳酸菌发酵及酸奶品质影响的结果最佳。

To study the effect of tea polyphenols on the fermentation of lactic acid bacteria and quality of yoghurt, fresh milk was packed in nine groups of 16 glass bottles with 100 mL each, respectively. The titration acidity, retention ability, texture, viable count of lactic acid bacteria, sensory evaluation, and other indexes of yoghurt were determined in the test. The result showed that the effect of tea polyphenols on the growth and reproduction of lactic acid bacteria exhibited a parabolic shape. Tea polyphenols had a significant effect （ P 〈 0.01 ） on the growth of lactic acid bacteria when adding lower than 0.30% of tea polyphenols, which had the best effect on the growth when the additive amount of 0.20%. Meanwhile, tea polyphenols had a certain inhibitory effect on lactic acid bacteria to produce acid, thereby extending the shelf life of yoghurt. The determination results of both retention ability and texture of yoghurt and sensory evaluation exhibited a parabolic change with the increase of the additive amount of tea polyphenols. When the additive amount of tea polyphenols was 0.20%, the mean value of every index showed the optimal result. The results indicate that the effect of tea polyphenols on the fermentation of lactic acid bacteria and quality of yoghurt reaches the optimal result when the additive amount of tea polyphenols was 0.20%.