In Vitro Antioxidative Activity and Antihypertensive Activity of Soy Sauce Cake Derived from the Manufacturing of Japanese Style Fermented Soy Sauce

Abstract

As the manufacture of soy sauce produces a large quantity of soy sauce cake as one of food processing waste, it is nec-essary to search for possible ways for their utilization. Chemical composition of soy sauce cake was analyzed to use as a material of high-value functional ingredients. The results showed that soy sauce cake could be potentially used as func-tional ingredients rich in proteins, with high antioxidative activitiy, free radical scavenging activity, and antihypertensive activity. Based on their IC 50 values, the hydrolysates from soy sauce cake were more significantly effective against superoxide anion radicals and ACE, compared with hydroxyl radicals and DPPH radicals. The present study indicates that a large amount of soy sauce cake can be used as source of proteins with good antioxidative activity, free radical scavenging activity, and antihypertensive activity. The utilization of soy sauce cake may be also to contribute to reduce food processing wastes and to resolve an environmental problem.