以青方腐乳为主要研究对象,分析了不同后酵时间段有结晶物青方腐乳样品相关指标的差异,并进行模拟实验,分析不同因素对结晶物产生的影响。结果表明:随着后酵时间的延长,腐乳卤汤中氨氮浓度持续增加,磷含量呈现先增加后减少的趋势,镁含量呈持续降低趋势,腐乳卤汤pH值逐渐升高;pH对于磷酸铵镁生成有非常强的依存性,氨氮浓度对磷酸铵镁结晶生成的影响程度很大,盐含量和酒精含量对磷酸铵镁结晶反应影响不显著。得出的主要结论为:后酵过程中氨氮浓度增大可能是青方腐乳结晶物产生量大的主要原因;低盐含量和高酒精含量有利于磷酸铵镁结晶的生成。

The purpose of this study is to prevent the generation of crystal in Sufu and provide foundation for its prevention in future.We took grey Sufu as the main study object and analyzed the differences of related indicators among green curd Sufu with crystal in different period of late fermentation.Then we did a model test based on different effectors that influence the production of crystal in Sufu.We found that along with the prolongation of the later fermentation,the concentration of NH 4 +and pH value of Sufu both were increasing.The content of P was increasing at first and decreasing later.The content of Mg was decreasing.The concentration of NH 4 +and pH value both had a great influence on the generation of MgNH 4 PO 4 ·6H 2 O.But salinity and the content of alcohol had little effect.Therefore,we could conclude that the generation of large amounts of crystal might be caused by the increasing concentration of NH 4 +which produced during long-term later fermentation period.Low salinity and high alcohol content would promote the generation of the crystal.