Study on the characteristics of taste compounds and taste of sweet soy sauce

In this paper, light soy sauce was used as control, the characteristics of proximate indices, molecular weight distribution of protein / polypeptide, amino acid composition and sensory attributes of sweet soy sauce were studied using proximate indices analysis, sodium dodecyl sulfate- polyacrylamide gel electrophoresis, high performance liquid chromatography in combination with sensory evaluation. Results showed that the contents of Na Cl, total sugar, reducing sugar, salt- free solid and total acid in sweet soy sauce were 28%, 172%, 176%, 120%and 58% higher than those in light soy sauce, however its amino acid nitrogen was approximate 35% lower than the control.The proportion and the content of protein / polypeptide with high molecular weight in sweet soy sauce were remarkably higher than those in the control. The amino acid composition of sweet soy sauce was characterized by a large amount of sweet amino acids ( 45%) , followed by bitter amino acids and umami amino acids; however, the amino acid composition of the control was characterized by dominant umami amino acids ( 57%) , followed by bitter amino acids and sweet amino acids.Sensory evaluation indicated that sweet soy sauce processed prominent tastes of salty and sweet, and a harmonious mixture of umami, sour and bitter, etc.