Study On The Quality Evaluation Of Dried Bean Curd Processed With Different Soybean Varieties

Dried bean curd is a great regional features traditional soy food in northeast of China. However, the different flavor and quality of dried bean curd are due to the inconsistencies of soybean material as well as differences in the production process. Inconsistency of raw materials was mainly as a result of the diversity of soybean varieties, rural household planting, mixed harvesting and storage. The varieties of soybean is the main factor that affect the quality of soy products. In this study, 25 soybean species were chosen to analysis the physical and chemical indexes of soybean seed, including weight, moisture content, fat content, protein content, water-soluble protein content, 7S protein, 11 S protein. Dried bean curd, which was coagulated with MgCl2,determination of dry yield and wet yield, physical and chemical indexes,texture indexes,color measurement, sensory evaluation indexes were tested. By variance and correlation analysis, the differences among varieties parameter analysis, the correlation between soybean components and quality indexes of dried bean curd,the correlation between sensory evaluation and instruments indexes. Then soybean varieties which were fitted to process dried bean curd were chosen by cluster analysis. The main findings were as follows:(1) The result showed that different soybean species had significantly different on weight, moisture content, protein, water-soluble protein, fat, 11 S protein and 7S protein.(2) Through the correlation analysis, 7S protein was significantly negatively correlated on dry yield. Soluble protein of soybean was significantly positively correlated with the moisture of dried bean curd. There was a significant positive correlation between fat and protein content of dried bean curd and there was a significant negative correlation between the soybean protein and protein content. The moisture of soybean, protein content was showed significant positive correlation with fat content of dried bean curd, and there was a significant negative correlation between soybean fat and the fat content of dried bean curd.(3) Flavor of sensory evaluation was significant positive correlation with hardness,gumminess,chewiness of texture characteristics. Taste of sensory evaluation was significant positive correlation to hardness and apparent was significant positive correlation with shear force range. Color of sensory evaluation was significant positive correlation to b* value.Therefore,there was some relevance between dried bean curd texture characteristics and sensory evaluation.(4) There was a significant negative correlation between hardness and soybean protein, water-soluble proteins and 7S protein. Springiness range of texture index was significant positive correlation with soybean fat and 11S/7S. Shear force range was significant positive correlation with moisture content, protein and fat of soybean.(5) Through cluster analysis and correlation analysis, HeFeng 55 and JiYu 202 were the best varieties to produced dried bean curd.