Quality characteristics and antioxidant activity of hickory-black soybean yogurt

Hickory-black soybean milk and reconstituted milk (about 12 g/100 g solid content) were mixed in the proportion of 2:3 by volume to prepare hickory-black soybean yogurt (HBY). Cow milk yogurt (CMY) with no addition of hickory-black soybean milk was used as the control. Compared with CMY, HBY had higher water holding capacity, fat, crude protein and amino acids, but lower susceptibility to syneresis and ash content, and had no significant difference in the total count of lactic acid bacteria (p > 0.05). Sensory evaluation showed that the appearance and flavor scores of HBY had no significant difference from CMY (p > 0.05), but the texture score was significantly higher (p < 0.05). IC50 values of DPPH center dot, center dot OH scavenging ability, Fe2+ chelating ability and inhibition of lipid peroxidation of HBY were lower (p < 0.05) than those of CMY. These results suggested that the antioxidant activity of HBY was significantly higher than that of CMY. (C) 2012 Elsevier Ltd. All rights reserved.