Analysis Of Microflora During The Processing Of Brassica Juncea Coss Var Tsatsai And The Research Of Starter Cultures

Pickled of mustard tuber (Brassica juncea var. tsatsai) is the Chinese special product cultivated locally, which has been recognized as one of the most famous pickling vegetables in the world. For the past years, sauerkraut has head for the"low-salt, healthy, green". Many researches have been done for updating the crafts and producing new variety of products, so the crafts optimized and the products presented more variety gradually. The modified crafts have simplified the process, and play an important role in the quality control of products.The fermentation process of microorganism is important for the pickling of Brassica juncea. To make clear microbial fermented type in the period of pickling is the basic for controlling the crafts process. Now, Yang et. al, has analyzed the category of microorganism in after ripening time of Szechwan preserved vegetable. However, the variational regulation of microflora is indefinite in different periods.In this research, Fuling Brassica juncea was chosed as experimental object. combined culture-dependent and culture-independent methods ( DGGE ) , the composition and the variational regulation of the different periods and different crafts were proved up primaryly, the principal microorganism and the function were determined, and the proportion of strain in different periods have also been researched. Moreover, the research of the reflection of inoculating microorganism on the quality and fermentated characteristic, provided theoretical and technical support for the the research of starter cultures. Depending on the research and use of starter culture, this article provide theoretical basis for development of suitable preparatory methods for enhancing quality of products, simplifying the crafts, and shortting the fermentation process.The main results were as follows:â‘ Following the fermentation process, the characters of Brassica juncea have changed correspondly. The pH of the Brassica juncea decreased during fermentation, while the increase of lactic acid. The total microorganism experienced a course of growth crest-time, then stabilizated gradually, and get to the peak value at about 25-30 d during fermentation process. This reflects that the close relationship of vital movement of microorganism and the mature of Brassica juncea.By the traditional culture method, the results of pure cultured morphology and physiology and biochemistry display that the main microorganism are the same, Lactobacillus and Saccharomyces rouxii are the main dominant flora in the immediate fermentation and the dehydration in air. Besides, the two saline tolerance strains of Halobacteria and Aerococcus were isolated only from the dehydration in air. We discovered the biodiversity of the dehydration in air is lower than that of the immediate fermentation.â‘¡These 16S rDNA sequences exhibited more than 97% identity compared with sequences present in the databases. Twenty-one dominant bands from DGGE bands were sequenced, The result showed that the intense bands were the Leuconostoc citreum,Lactobacillus sakei and Lactococcus lactis subsp. Lactis, simultaneously, W. confuse and uncultured eubacteria were also found in DGGE profiles.â‘¢The inoculated fermentated products has the similar oranoleptic indicator with the wild fermentated products, and the variety isn't obviouse. However, the content of nitrite has reduced obviously in the inoculated fermentated products. It indicate that starter culture does not influence on the flavor and the quality of Brassica juncea, but speeds up the formation of flavor, shortens the period of production, cuts down the cost, and rises the security of the Brassica juncea products.