The Research Of Microbial Diversity On Northeast Traditional Sticky Bean Bun Sourdough And Its Relationship With The Physical And Chemical Properties

Traditional Sticky Bean Bun(SBB)as a kind of fermentation food from manchuria special products in northeast China were naturally fermented using wild strains packaged with steamed bean paste by hands.It has good flavor,rich nutrition and can fight hunger hardy.Although traditional SBB tasted delicious,the characteristic of quality and taste were affected by different raw material ratios and various regions.The purpose of this research is based on different ratios of the northeast traditional SBB made of the dough,and its microbial flora diversity and quality characteristics were analyzed.The fermented sourdough is made of four raw materials including rice,glutinous rice,sticky corn and large yellow rice and it is divided into four groups according to the proportion of materials.The key analysis of northeast traditional natural fermentation SBB ratio of different raw materials fermented dough microbial flora composition,focused on the ratio of different materials of the diversity of microbial components of fermented dough,its influence on the quality characteristics.The flora composition of the traditional natural fermentation SBB were analyzed by using the polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE)fingerprint technique and combining with the high-throughput sequencing technology,and the dough to determine whether there are the advantage bacterium groups and specific strains of comparative advantage bacterium groups,analyzing the diversity of dominant fungi,comparing the rheological properties of SBB at the same time,to explore differences and relevance between rheological properties and microbial flora structure,for improving quality of SBB,developing exclusive starter cultures,realizing the dough microbial industrialized production,SBB scale processing to provide theoretical support.The results showed that:1.The bacteria flora diversity in traditional SBB fermentation sourdough is rich,16 sourdoughs were analyzed by PCR-DGGE,which detected five genera and 18 species.The predominant microflora were Lactobacillus sakei and Leuconostoc lactis.Leuconostoc citreum and Lactobacillus helveticus were the subdominant bacteria.Group D sample owns the most abundant species diversity;Further studies conducted the specificial of LAB PCR-DGGE technology revealed the predominant LAB identified as Lactobacillus sakei and Weissella confusa.Lactobacillus acidophilus and Leuconostoc pseudomesenteroides were the subdominant LAB during the period of sourdough fermentation,respectively.The lactic acid bacteria are the most abundant the fermented sourdoughs of D group.In conclusion,the group D bacteria flora which made of rhubarb rice and corn is rich,which is superior to other materials combination producing SBB fermentation sourdough.2.The fungal flora diversity in traditional SBB fermentation sourdough is various,a total of 15 strains were detected,including total of 11 strains of yeast,mold 4 strains.Guehomyces pullulans and Candida zeylanoides exists in three groups of all samples can be considered as the predominant fungus.Kazachstania servazzii,Dabaryomyces hansenii,Guehomyces pullulans is the advantage of the four groups of SBB fermentation sourdoughs by using Specific PCR-DGGE technology of yeast further,in which A group of the most abundant species of yeast.Comprehensive analysis of group A fermentation sourdough of fungal diversity than others groups is richest,the environment of SBB fermentation sourdough which made of polished glutinous rice and rice provides more nutrients and choices for fungi,is more suitable for the growth of fungi.3.Analysis of microbial diversity by using High-throughput sequencing technology were detected 35 species of bacteria in four groups samples at the same time.Lactobacillus,Weissella and Lactococcus were identified as the predominant bacteria for four groups sourdoughs samples;the fungal microbial were detected 35 species of all sourdoughs,and the advantage of fungal has a very big difference for the four groups of fermentation sourdoughs.4.The pH,TTA and the rheological characteristics including viscosity and elasticity of SBB sourdoughs before and after heating has correlation with microbial flora.Research results show that:Analysis of microbial diversity were different in raw material composition and ratio SBB fermentation sourdough samples by using PCR-DGGE and High-Throughput Sequencing technology,the group of yellow rice and corn as raw material has more abundant bacteria species,fungi flora of the other group which made of polished glutinous rice and rice is richest,the quality characteristics and microbial flora is making a big difference.Raw material composition of yellow rice and polished glutinous rice,corn and rice can be used as a good ratio of application in traditional fermentation production of SBB production,Lactobacillus sakei,Leuconostoc lactis can be used as a candidate bacteria strains to SBB dedicated the development of starter cultures,their research for the SBB production industrialization provide strong theoretical basis.