Effect of light on soy sauce fermentation

The effect of different light qualities on soy sauce fermentation was studied.The results showed that there were no significant difference(p0.05) in sensory evaluation(color,aroma and taste) and physicochemical properties(color index A530,ammonia nitrogen,solid content,reducing sugar,total acid,red index and yellow index) between different soy sauce.The comparative analysis of the temperature-controlled fermented soy sauce and the traditional Chinese-type soy sauce showed that the activities of the neutral proteases and acid proteases of the former declined more quickly during fermentation,while it’s content of ammonia nitrogen increased more quickly compared to those of latter.Correspondingly,the content of free amino acids in the temperature-controlled fermented soy sauce(5.246g/100ml) was significantly higher than that of traditional Chinese-type soy sauce(4.480g/100ml).Furthermore,the volatile aroma compounds were analyzed by GC-MS.The results showed that the volatile compounds in the temperature-controlled fermented soy sauce were more complex,and the contents of alcohols,organic acids,esters,aldehydes,phenols and other volatile compounds in the temperature-controlled fermented soy sauce were higher than those in the traditional Chinese-type soy sauce.