真空包装免泡豆杆优势腐败细菌分离鉴定及其致腐能力分析  

Isolation,Identification and Evaluation of Dominant Spoilage Bacteria from Vacuum-Packaged Nonrehydrated Dougan,a Chinese Traditional Rod-Shaped Soybean Product Prepared with Protein-Lipid Film

作　　者：郑丽君[1] 申光辉[1] 张志清[1] 李辰凤 陈安均[1] 黎杉珊[1] 吴贺君[1] 罗松明[1] ZHENG Lijun;SHEN Guanghui;ZHANG Zhiqing;LI Chenfeng;CHEN Anjun;LI Shanshan;WU Hejun;LUO Songming(College of Food Science, Sichuan Agricultural University, Ya’an 625014, China)

机构地区：[1]四川农业大学食品学院,四川雅安625014

出　　处：《食品科学》2018年第2期177-184,共8页Food Science

基　　金：四川农业大学校企合作项目(060H0301);四川农业大学"双支计划"项目(03572107);四川省教育厅川菜发展研究中心重点规划项目(CC2017Z01)

摘　　要：以真空包装免泡豆杆为研究对象,分离鉴定其中的腐败细菌,并分析耐高温优势腐败菌的腐败能力,为产品质量控制提供参考。采用选择性培养基对免泡豆杆中腐败细菌进行分离纯化,并测定菌株的耐高温及产蛋白酶能力,通过形态、生理生化特征结合16S rRNA、gyrB基因序列分析对优势腐败细菌进行分类鉴定。将优势腐败菌接种到无菌免泡豆杆中,通过样品感官评价、质构特性、挥发性盐基氮值(TVB-N)、蛋白酶活力及p H值的分析,比较不同腐败菌株对免泡豆杆的腐败能力。从腐败样品中共分离获得20株不同的腐败菌,其中有12株可耐受110℃、20 min高温处理,且具有较强的产蛋白酶能力。回接验证实验结果表明,接种4株优势耐高温腐败菌的免泡豆杆样品,37℃贮藏至第7天发生明显腐败变质,样品TVB-N、蛋白酶活力及p H值显著高于未接菌对照样品;此外,硬度、弹性、胶着性、耐咀性等产品质构特性也显著低于对照样品。4株优势腐败菌均为芽孢杆菌,通过比较TVB-N产量因子确定腐败能力最强的是解淀粉芽孢杆菌(Bacillus amyloliquefaciens)DY1a,其次依次分别为解淀粉芽孢杆菌DY1b,枯草芽孢杆菌(B.subtilis)DY3和DY2a。The purpose of this study was to isolate and identify the bacteria responsible for spoilage of vacuum-packaged nonrehydrated Dougan（a Chinese traditional rod-shaped soybean product prepared with protein-lipid film） and to evaluate the spoilage potential of the heat-resistant bacteria.The bacteria were isolated using various selective media.The dominant spoilage bacteria were identified by morphological observation,physiological and biochemical characterization,and 16 S rRNA and gyrB gene sequence analysis.The heat-resistant spoilage bacteria with higher protease-producing capacity were inoculated into sterilized Dougan to evaluate the spoilage potential according to the sensory quality,textural properties,total volatile basic nitrogen（TVB-N） content,protease activity and p H of Dougan.A total of 20 bacterial strains were isolated from spoiled nonrehydrated Dougan,and among these isolates,12 strains with higher protease-producing capacity could survive autoclaving at 110 ℃ for 20 min.The Dougan inoculated with strains DY1 a,DY1 b,DY2 a and DY3 showed obvious signs of spoilage after storage at 37 ℃ for 7 days.The TVB-N,protease activity and p H value of the inoculated samples were significantly higher than those of the non-inoculated control.Texture profile analysis indicated that hardness,springiness,gumminess and chewiness of the inoculated sample decreased significantly compared with control samples.All four specific spoilage bacteria belonged to the Bacillus genus.According to the TVB-N yield factors（Y（TVB-N/CFU） values）,the spoilage potential of B.amyloliquefaciens DY1 a was the strongest among the spoilage bacteria isolated,followed subsequently by B.amyloliquefaciens DY1 b,B.subtilis DY2 a and B.subtilis DY3.

关 键 词：免泡豆杆 芽孢杆菌 gyrB基因 腐败能力 质构特性 

分 类 号：TS201.3[轻工技术与工程—食品科学]