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

Abstract:

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.