Flavor and taste compounds analysis in Chinese solid fermented soy sauce

The analysis of free amino acid and volatile compounds were conducted to understand the changes in taste and flavor of five samples which were solid fermented. The values of bitter, sweet and MSG-like free amino acids in these soy sauces were significantly different. The taste of soy sauce was predominated by saltiness, followed by moderate “umami” and sweet taste and slight bitterness, likely as a result of the balance and interaction among different taste components. A total of 82 kinds of volatile compounds were identified, including alcohols, acids, esters, aldehydes, ketones, phenols, heterocyclic compounds, alkynes and benzenes. The subtle aroma of the soy sauce seemed to depend not only on particular key compounds but also on a “critical balance” or a “weighted concentration ratio” of volatile compounds.