Physicochemical, microbial, and rheological properties of yogurt substituted with pectic polysaccharide extracted from Ulmus davidiana

Abstract

This study aimed to evaluate the possibility of substituting the commercial pectin (control) in yogurt with pectic polysaccharide extracted from Ulmus davidiana (UDP) and investigate the physicochemical, microbial, and rheological properties of yogurt substituted with UDP (0.2%–0.6%, w/v) after 15 days of storage. Yogurt substituted with UDP contained more lactic acid bacteria than control due to the rhamnogalacturonan structure of UDP, indicating its usability as a prebiotic to promote the growth of lactic acid bacteria. The syneresis of yogurts substituted with low concentrations of UDP (0.2%–0.4%, w/v) was significantly lower than control. According to the steady and dynamic shear rheological measurements, all samples showed shear-thinning behaviors and weak elastic gel structures. These results suggested that 0.2% (w/v) UDP can be substituted for the commercial pectin in yogurt manufacturing to improve the syneresis and lactic acid bacteria counts of yogurt. Practical applications Pectin is a safe food ingredient that usually used in dairy industry to prevent protein aggregation, serum separation, and even increase health benefits of the food products. The physicochemical, microbial, and rheological properties of yogurt substituted with pectic polysaccharide extracted from Ulmus davidiana (UDP) were evaluated in the present study. Our results found that yogurt substituted with 0.2% (w/v) UDP exhibited lower syneresis and increased the lactic acid bacteria counts when compared to the control. Thus, 0.2% (w/v) UDP is recommended for yogurt manufacturing to reduce syneresis and promote the growth of lactic acid bacteria effectively.