瓜尔豆胶对乳酸菌增殖及酸奶品质的影响

Effect of Guar Gum on the Growth of Lactic Acid Bacteria and the Quality of Yogurt

以部分水解瓜尔豆胶(PHGG)为研究对象,通过测定酸奶的乳酸菌活菌数、pH和滴定酸度、粘度、持水力、感官评分等指标,研究PHGG对常用酸奶发酵剂菌株保加利亚乳杆菌、嗜热链球菌的发酵特性及酸奶品质的影响。结果表明,PHGG对两种乳酸菌的生长和产酸都有明显的促进作用,在冷藏期间酸奶活菌数始终高于空白组,且不会造成严重的后酸化。随着PHGG添加量的增加,酸奶的粘度、持水力显著增加,PHGG质量浓度为20 g/L时粘度是空白组的1.7倍。感官评分随着PHGG添加量增大呈倒U型变化,在PHGG质量浓度为10～15 g/L时酸奶的品质达到最佳。研究表明,PHGG可以促进酸奶中乳酸菌的生长,提高酸奶的感官和质构品质。

The effect of partially hydrolyzed guar gum(PHGG) on the quality attributes of yoghurt was studied. The total number of lactic acid bacteria,pH,titratable acidity,viscosity,water holding capacity and sensory properties of the yogurt were evaluated for investigated its effects on the fermentation characteristics of Lactobacillus bulgaricus and Streptococcus thermophiles strains. The results showed that PHGG has stimulatory effects on the growth and acid production of Lactobacillus bulgaricus and Streptococcus thermophiles. The numbers of colony forming units(cfu) obtained from yogurt containing PHGG were significantly higher than control during the entire storage period,and could not shorten the after acidification process of yogurt. The addition of PHGG could improve viscosity and water holding capacity,20 g/L PHGG can effectively improve viscosity by 1.7 times when compared with control. Sensory properties were affected by PHGG addition,the yogurt with 10 15 g/L scored best. In conclusion,PHGG had promoting effects on lactic acid bacteria growth and yogurt quality.