传统臭鸡蛋腌制中细菌区系变化及挥发性风味物质分析

Diversity of Bacterial Community and Flavor Substances in Naturally Fermented Stinky Egg

探究传统臭鸡蛋腌制过程中细菌区系动态变化规律及主要的挥发性风味物质。采用变性梯度凝胶电泳(PCR-DGGE)技术,对不同腌制阶段的臭鸡蛋样品总DNA的V3区进行扩增、测序和分析,用GC-MS方法检测臭鸡蛋中的风味物质。经分析,共有42种微生物参与臭鸡蛋腌制过程,其中12种主要菌株分属于6个属:海杆菌属、盐厌氧菌属、嗜盐乳酸菌属、盐单胞菌属、海境劳胞杆菌属,盐乳芽胞杆菌属以及不可培养物。在臭鸡蛋腌制过程中,微生物细菌菌系结构存在演替,依据臭鸡蛋品质变化情况,将臭鸡蛋腌制阶段分为4个时期,菌株海境劳胞杆菌sp.Band12和盐单胞菌sp.Band25为臭鸡蛋腌制过程中的优势菌株。腌制前期(0~7 d)和中期阶段(8~21 d),盐单胞菌属微生物含量最高,分别为总量的26.94%和30.97%;其次为嗜盐乳酸菌属,分别含8.02%和10.91%;在腌制后期(22~28 d),海境劳胞杆菌属微生物成为优势菌,含量为23.96%;腌制末期(29~60 d),盐单胞菌属和嗜盐乳酸菌属为主要微生物,约占总量的20%左右。经HS-SPME/GC-MS分析,臭鸡蛋挥发性风味物质主要为二甲基三硫、二甲基二硫、4-甲基戊酸、3-甲基丁酸丁酯、丁酸和2-甲基己酸等18种物质。本研究首次研究我国传统臭鸡蛋腌制过程中的细菌区系变化,明确海境劳胞杆菌和盐单胞菌属微生物为臭鸡蛋腌制过程中的优势微生物属,硫化物为主要挥发性风味物质,为臭鸡蛋现代化生产提供一定的理论依据。

The aim of this study was to explore the bacterial diversity and the main special flavor of the stinky egg,using PCR-DGGE and HS-SPME/GC-MS technology.The result indicted that a total of 42 microorganisms were found in the whole stage,and 12 species belonging to Marinobacter,Halanaerobium,Marinilactibacillus,Halomonas,Paraliobacillus,Halolactibacillus and Uncultured bacterium.In the early stage(0-7 d)and middle stage(8-21 d)of fermentation,the biomass of Halomonas was the highest,accounting for 26.94%and 30.97%,respectively.Paraliobacillus was the major bacteria during the late stage(22-28 d),the microbe abundance was 23.96%.During the final stage of fermentation(29-60 d),Marinilactibacillu and Halomonas are the dominant microorganisms.The strain Paraliobacillus sp.Band 12 and strain Halomonas sp.Band 25 were the dominant microorganism species involved in the whole fermentation stage.In the stinky egg,a total of 18 special flavor were detected,such as dimethyl trisulfide,dimethyl disulfide,4-methyl valeric acid,butyl 3-methylbutyrate,butyric acid and 2-methylhexanoic acid.Finally,the present research enriches the knowledge of the traditional fermented food-related bacteria,as well as improve the quality and safety of the stinky egg.