食醋浑浊现象的微生物因素分析与探讨

目的对明显有浑浊现象的食醋样品进行分析,了解和探讨浑浊是否由微生物因素引起。方法以浑浊食醋、醋醅为测试样本,采用感官评定、微生物培养、显微镜检、加热灭菌实验等手段对食醋浑浊的原因进行分析,并对醋醅分离出来的微生物采用全自动微生物生化鉴定仪进行鉴定。结果采用平板计数法和薄膜过滤法培养浑浊食醋,样本均未检出,醋醅样本有检出。染色结果显示浑浊食醋样本A中发现有未知革兰氏阴性菌和酵母菌,并无明显增殖现象;样本B中未检出微生物;醋醅样本检出酵母菌和未知革兰氏阴性菌。晶形镜检和加热灭菌试验表明,浑浊成分有糊精和蛋白质。结论食醋样本浑浊现象产生原因不是由可培养微生物引起,可能是非可培养微生物或者是非生物因素引起。

Analysis and discussion on microbial factors of turbidity of vinegar

Objective To analyze the samples with obvious turbid phenomenon, and to understand whether the turbidity caused by microbial factors. Methods Both turbid vinegars and vinegar culture sample were analyzed by sensory evaluation, microbial culture method, microscopic examination and heat sterilization. The isolated microorganisms were identified by automatic microbial biochemical analyzer. Results Samples were not detected by plate count method and membrane filtration method while vinegar culture sample was detected. Dyeing results showed that unknown gram-negative bacteria and yeast were detected in sample A with no obvious proliferation by microscope, but microorganisms were not detected in sample B. Yeast and unknown gram-negative bacteria were isolated and identified in vinegar culture sample. According to crystal microscopic examination and heating sterilization, turbidity ingredient contained dextrin and protein in vinegar. Conclusion The turbidity of vinegar samples is not caused by culturable microorganisms, and it may be caused by non-culturable microorganism or abiotic factors.