[关键词]
[摘要]
本研究从酱醪中筛选得到了一株嗜盐片球菌,该微生物扩大培养后在酱醪发酵前期添加1×106 CFU/g到酱醪中并按照高盐稀态酱油酿造工艺进行生产。所得酱油于50 ℃/震荡条件(200 r/min)下进行破坏性实验。利用肉眼观察法和冷冻-离心法检测其二次沉淀形成时间和生成量,利用高效液相色谱法测定其生物胺含量,利用滴定法和定量描述分析法对酱油理化指标和风味进行评价。结果发现嗜盐片球菌显著延迟了(15 d)酱油二次沉淀出现时间并减少了酱油二次沉淀生成量(89.12%,p<0.01)和生物胺含量(55.21%,p<0.01),其中色胺和酪胺含量分别下降了100%和77.00%。由于嗜盐片球菌利用酱醪中的糖类物质(总糖和还原糖下降56.32%和64.56%)产生了酸类物质(增加29.80%),因此导致了酱油酸味及酸香和焦糖香增强,甜味减弱。添加嗜盐片球菌导致的酱油滋味和香气的改变容易通过勾兑工艺进行调整,因此在酱醪发酵阶段添加嗜盐片球菌是解决国产酱油二次沉淀和生物胺问题的有效手段。
[Key word]
[Abstract]
In this work, a strain of Pediococcus halophilus was isolated from soy sauce moromi and amplified, which was inoculated into the moromi of soy sauce on its early fermentation stage in the amount of 1×106 CFU/g moromi, then the resulting moromi was managed according to the protocol of high-salt and diluted-state soy sauce. The end product was subjected to destructive test under 50 ℃ with shaking of 200 rpm. Then the formation time and content of secondary precipitate were determined using naked eye observation/refrigerated centrifugation, the level of biogenic amine was detected with high efficiency liquid chromatography, the physicochemical indices and flavor were evaluated using titration method and quantitative descriptive analysis (QDA). It was found that Pediococcus halophilus deferred the occurrence of the secondary precipitation for 15 d and reduced 89.12% (p<0.01) of the secondary precipitate and 55.21% of the biogenic amine content (p<0.01), in which tryptamine and tyramine reduced 100% and 77.00%, respectively. The carbohydrate (total sugar and reducing sugar decreased by 56.32% and 64.56%, respectively) in moromi was converted into organic acids (increased by 29.80%) by Pediococcus halophilus, which enhanced the taste of sourness and the notes of sourness and caramel, lowered the taste of sweetness of soy sauce. The changes of taste and aroma of soy sauce caused by inoculating Pediococcus halophilus can be easily adjusted by blending procedure. Therefore, it is a potential method to solve the problems of secondary precipitation and biogenic amine in Chinese-type soy sauce by inoculating Pediococcus halophilus during its early moromi fermentation.
[中图分类号]
[基金项目]
国家自然科学基金项目(31301538);中山市重大科技专项项目(2018A1007);中国博士后科学基金项目(2016M600380);江苏大学启动基金(15JDG057)