Characterization of taste and aroma compounds in Tianyou, a traditional fermented wheat flour condiment.

Taste and aroma compounds in Tianyou were determined using HPLC and GC-MS/GC-olfactometry. By comparison with light soy sauce (control), the contents of salt, sugar, total nitrogen and total acid in Tianyou were higher, while the contents of umami, sweet and bitter free amino acids, and the percentage of 1-5kDa peptides in Tianyou were lower. Thirty-one aroma-active compounds were identified in both Tianyou and the control (30 compounds in common). Aroma extraction dilution analysis indicated that most flavor dilution factors of aroma-active compounds were lower in Tianyou than the control. Quantitative descriptive analysis showed that Tianyou had significantly stronger salty and sweet tastes, weaker umami taste and weaker malty, caramel-like and smoky notes when compared to the control (p<0.05), which were in agreement with the analyses of taste and aroma compounds. This confirms that Tianyou has a distinctively different flavor from light soy sauce.