Effect of solid concentration on the taste of soy sauce with high salt liquid state fermentation

The effects of different solid concentrations on the taste of soy sauce with high salt liquid state fermentation were systematically analyzed by investigating the neutral protease activity, amino acid nitrogen, total nitrogen, reducing sugar, total acid, amino acids composition, molecular weight distribution and taste characteristic. Results showed that the higher solid concentration led to the lower salt content in soy sauce, which remained higher neutral protease activity, amino acid nitrogen, total nitrogen, reducing sugar and total acid.Compared with the key taste substance of soy sauces fermented under different solid concentrations, molecular weight of different soy sauces were mostly distributed in 1 ~5 ku ( 50%) and less than 1 ku ( 30% ~40%) . Furthermore, the peptides with 1 ~ 5 ku and flavor amino acids also improved under higher solid concentration fermentation.The Quantitative Description Analysis ( Qu) showed that the umami and sour taste were strongest in soy sauce under solid concentration of 37%, while the bitterness was the weakness. Thus, soy sauce fermented under high solid concentration efficiently improved the taste.