Processing Suitability And Amino Acid Nutritional Value Evaluation Of Whole Soybean Curd Of Different Soybean Varieties

Whole soybean curds(WSCs)as a new type of whole soybean products,the processing can avoid the loss of water-soluble protein and retain all kinds of bioactive substances in soybean,such as isoflavones,dietary fiber,saponins and oligosaccharides.To understand to processing suitability of WSCs of different soybean varieties,this study mainly explores the processing characteristics and amino acid nutritional value of WSCs from different soybeans.1 The composition of 19 soybean materials such as protein,fat,calcium,phosphorus,phytic acid,soluble protein contents and 7S / 11 S ratio showed significant differences among species according to the difference and correlation analysis.The difference of quality indexes of WSCs in yield,water holding capacity,water content,springiness,cohesiveness and resilience were relatively not significant,while hardness,adhesiveness,gel strength showed quite great variety difference.It was found that the yield of WSCs was positively correlated with the content of ?' subunit,and negatively correlated with the content of calcium and basic subunit(B),while the water holding capacity was significantly positively correlated with protein content and acidic subunit(A),and negatively correlated with fat content and basic subunit(B).The gel strength and hardness of WSCs were positively correlated with soybean protein content,and had an extremely significant or significantly negative correlation with the content of fat,while the texture characteristics such as gumminess and chewiness were also affected by protein and fat content.Gel strength,gumminess,and chewiness were significantly negatively correlated with the content of ? subunit,and significantly or extremely significantly positively correlated with the content of ? subunit.The contents of calcium,phosphorus,and phytic acid had little effect on the quality characteristics of WSCs.The clustering results showed that the WSCs were divided into four categories according to its processing characteristics.The yield,water-holding capacity,gel strength and texture characteristics of WSCs made from Dongdou17,Sudou12,Nandou12(Relay intercropping),Nanxiadou25,Jidou12,Nandou25,and Wuxing4 soybean cultivars were the highest,which showed a promising developing resource for the fabrication of WSCs.2 The results showed that Bayes discriminant analysis can predict the processing characteristics of 10 kinds of soybean raw materials,and the prediction reached to 70%,and the accuracy was high.3 The results showed that the protein content of WSCs made from different soybean materials was lower than that of okara-filtered soybean curds(OFSCs),while its content of total amino acids and essential amino acids were higher than OFSCs.The essential amino acid pattern of WSCs was basically close to amino acid pattern spectrum requirements except valine and sulfur amino acids.Methionine(Met)represented less than 0.4 for protein digestibility corrected amino acids score in all soybean curds except WSCs made from relay-cropping-Nandou12 and Nandou25,and it showed that methionine is the first limiting amino acid of soybean curd products.The comprehensive scores of WSCs and OFSCs were calculated by using the method of principal component analysis and comprehensive evaluation.Among them,the highest comprehensive scores of Nandou25 and Nandou12 were 5.33 and 5.27,respectively,and all the comprehensive scores of whole soybean curd were higher than that of OFSCs.