郫县豆瓣中特定腐败菌微生物效应的研究

Study on microbial effects of specific spoilage bacteria from Pixian bean paste

通过研究特定腐败微生物对豆瓣品质变化的影响,明确其微生物效应,为生产中更好的控制微生物繁殖和延长产品货架期提供理论基础。方法:将引起豆瓣变质的两种特定腐败菌———枯草芽孢杆菌和膜醭毕赤酵母菌,以单一和混合方式接种到豆瓣酱中,经培养后对感官、细菌总数、pH、氨基酸态氮含量等四项指标进行考察。结果:通过感官评价可知混合组在第9天完全腐败,枯草芽孢杆菌组为15天,膜醭毕赤氏酵母菌组为12天;各实验组中特定腐败菌的微生物效应为:混合组的细菌总数增加10.08倍、pH值上升1.95,高于枯草芽孢杆菌组(5.55,1.195)和膜醭毕赤氏酵母菌组(3.24,1.585);枯草芽孢杆菌组氨基氮含量降低了57.0%,高于膜醭毕赤氏酵母组(54.7%)和混合组(50%)。结论:枯草芽孢杆菌和膜醭毕赤氏酵母菌是导致郫县豆瓣腐败的主要腐败菌,彼此具有微生物协同效应,其中产品中氨基氮含量降低主要由枯草芽孢杆菌引起。

In order tO verify the microbial effect which caused deterioration, and provide theoretical basis of controlling the micro-organisms multiplying and extending the product＇s shelf-life, this assay was designed to study the quality change caused by specific spoilage organisms in Pixian bean paste. Methods： Two specific spoilage bacteria Bacillus subtilis and Pichia membranaefaciens were inoculated into the bean paste in the simple and mixed ways, to detect the four indicators, cultured sensory; total bacterial count, pH value, and amino nitrogen content. Results： The sensory evaluation showed that the complete corruption time of the mixed group was the 9th day, the Bacillus subtilis group was the 15th day, and the Pichia membranaefaciens group was the 12th day; the microbial effect of specific spoilage microorganisms in 3 groups were as follows： The bacteria number of the mixed group was in creased significantly （ 10.08 times ） , similar to the pH value （ 1.95 ） , which was higher than Bacillus subtilis group（5.55, 1. 195） and Pichia membranaefaciens group（3. 24,1. 585）; The amino nitrogen content of the Bacillus subtilis group was decreased 57. 0%, and the proportion was higher than the Pichia membranaefaciens group （54.7%） and the mixed group （50%）. Conclusion： Bacillus subtilis and Pichia membranaefaciens are the main spoilage bacteria in Pixian bean paste corruption, and they have the microbial synergy effect with each other. The assay result also showed that the amino nitrogen content decreased was mainly caused by the Bacillus subtilis.