Study On Changes In Isoflavone Composition Chemical Property In Sufu (Fermented Tofu) Production

Based on the experimental design of the different salinity of the samples were detected using high performance liquid chromatography and in sufu fermentation process of soybean isoflavones (daidzin, genistin, daidzein, and genistein) content during the fermentation of soybean for different fermented bean curd changes in flavonoids more systematic research in order to provide a theoretical basis for research and production, to improve the traditional fermented bean curd processing technology to produce high aglycone content in fermented bean curd, soy isoflavones to address the needs of the human body to provide a new way.Determination of moisture in sufu fermentation process, proteins, free amino nitrogen, pH, and fat and free fatty acid content in order to understand some of fermented bean curd in the dynamic changes of the fermentation process, in order to improve the fermentation of sufu production mechanism and the maturity of the fermented bean curd degree of control to provide a theoretical basis. At the same time liquid samples at different stages of structure parameters (such as hardness, elasticity, cohesiveness, etc.) tracking and detection, through the fermentation process of fermented bean curd texture analysis parameters, and low-salt fermented bean curd (salt content 10%) traditional fermented bean curd (salt content 15%) compared to draw milk fermentation process changes of texture properties, so as to provide a quantitative research and the production of reference and theoretical basis. Study the following conclusions:The study on isoflavone contents and composition showed that the total content of isoflavones gradually decreased during processing; The loss of isoflavones was mainly attributed to the preparation of tofu(the content of salt is 53.2% in soybean) and salting of pehtze (the content of salt is 54.8%); ripening did not significantly affect the total isoflavone contents. The isoflavone composition was altered during processing. The levels of aglycones(daidzein and genistein) increased, while the corresponding levels of glucosides(daidzin and genistin) decreased. And the total content of isoflavones under 10% content of salt is higher than it under 15% content of salt; the decreasing speed of isoflavones glucosides(daidzin and genistin) under 10% content of salt is faster than it under 15% content of salt. Isoflavones in the form of glucosides(daidzin and genistin) almost have been completely transformed into isoflavones aglycones(daidzein and genistein) during ripening, suggesting that sufu manufacturing might be beneficial to enhance its physiological function.The study on chemical composition showed that the free amino acid content increased during processing, while the protein content gradually decreased. The protein and free amino acid content under 10% content of salt is more than it under 15% content of salt, and the maturation time under 10% content of salt is shorter than it under 15% content of salt. The pH value increased significantly during pre-fermentation and salting and gradually decreased during ripening; The pH value under 10% content of salt is more than it under 15% content of salt. The free fatty acid content increased during processing, while the fat content gradually decreased, but the free fatty acid content did not significantly be affected. The fat and free fatty acid content under 10% content of salt is more than it under 15% content of salt.The study on texture showed that The hardness increased at first and then decreased in ripening, after ripening at 30 days (10% content of salt) and 40 days after the fermentation (15% fermented bean curd) stabilized, which indicated the hardness of sufu did not significantly be affected after it having been mature; the hardness under 15% content of salt is more than it under 10% content of salt The adhesiveness gradually increased during processing; the adhesiveness under 10% content of salt is more than it under 15%content of salt. The springiness gradually decreased during processing, after ripening at 30 days (10% content of salt) and 40 days after the fermentation (15% fermented bean curd) stabilized, which indicated the springiness of sufu did not significantly be affected after it having been mature; the springiness under 15% content of salt is more than it under 10% content of salt...