A model to reduce tyrosine crystallization in Chinese fermented soybean curd by adjusting NaCl,ethanol and temperature during fermentation  

作　　者：Jia Deng Lijun Yin Xi Yang Xin Jia 邓笳;殷丽君;杨熙;贾鑫(College of Food Science&Nutritional Engineering,China Agricultural University,Beijing,China)

机构地区：[1]College of Food Science&Nutritional Engineering,China Agricultural University,Beijing,China

出　　处：《Food Quality and Safety》2024年第2期356-368,共13页食品品质与安全研究（英文版）

基　　金：supported by the National Key Technologies Research and Development Program(No.2021YFD2100102);the Key Research and Development Program of Shandong Province(No.2022CXGC010602),China.

摘　　要：Objectives:White spots,mainly consisting of tyrosine,refer to small white particles that exist on the surface of mature Chinese fermented soybean curd or in the fermentation broth and have affected the appearance of Chinese fermented soybean curd.Materials and Methods:The study determined the composition of the white spots throughout mass spectrometry and high-performance liquid chromatography and investigated the relationship between tyrosine content,amino acid nitrogen content,depth of the proteolysis index and protease activity to interpret the mechanism of white spot formation during fermentation.Results:In this study,the results confrm that tyrosine accounts for 78.22%of the white spots.Excessive tyrosine content can promote the formation of white spots during fermentation.Free tyrosine content,amino acid nitrogen content,depth of the proteolysis index and protease activity during the fermentation process increased during fermentation.Correlation analysis results show that free tyrosine content was positively correlated with amino acid nitrogen content,depth of the proteolysis index and protease activity,which showed that the production of tyrosine is related to the degree of proteolysis.Solubility studies show that high concentrations of NaCl and ethanol affect the production of tyrosine and reduce its solubility,while the increase in temperature increases the solubility of tyrosine.Taking NaCl,ethanol and temperature as infuencing factors,a mathematical model of tyrosine solubility was established.Conclusion:This study lays the groundwork for understanding the mechanism of white spot formation during Chinese fermented soybean curd fermentation and provides solutions for controlling white spot formation.

关 键 词：Chinese fermented soybean curd white spots TYROSINE mathematical modeling 

分 类 号：TS214[轻工技术与工程—粮食、油脂及植物蛋白工程] TS255[轻工技术与工程—食品科学与工程]