The Study On Microbiological And Metabolic Property In Natural And Stater Culture Fermentation Of Chinese Sauerkraut

Chinese sauerkraut is a traditional fermented vegetable food originated in Chinathousands of years ago, which is delicious, crisp, healthy and contains muchnutrients.As a kind of fermented food, the properties of sauerkraut are given by themetabolic activities of the microbe. Lactic acid bacteria(LAB), acetic bacteria, yeastand mould mainly take charge of the natural fermentation, while the LAB manage thestater culture fermentation. therefor, it is important to study the microbiological andPhysicochemical changes and metabolic activities of the natural and stater culturefermentation of sauerkrauts, with which we can deeply understand the co-metabolismactivities of different microbe in China sauerkraut. In this study, natural and staterculture fermentation of Chinese sauerkraut were performed in traditional way andsamples were taken every12hours for7days, then the changes of microbiological,pH value and metabolites were studied. The results were given as follows:1) In natural fermented sauerkraut, LAB, acetic bacteria, yeast and mould tookcharge of the fermentation. In the initial stage, more LAB and acetic bacteria thanyeast and mould were found. Then the LAB grew fast and reach108level after24hours and dominated the fermentation. The acetic bacteria and yeast and mould alsogrew rapidly in the first24hours and their counts reach the maximum. The LAB didnot show decline in counts till the end of fermentation, however, the acetic bacteriadie out after3days fermentation since the formation of anaerobic environment, andthe yeast and mould also disappeared after3days because of the pH decline and theaccumulation of organic acid.2) In natural fermented sauerkraut, the pH of brine reduced rapidly from5.75to4.20in24hours, then it turn to slowly and remained stable till the end offermentation. Sucrose was utilized in abundance during fermentation. The content ofglucose and fructose increased initially and then decreased, then increased slowly tillthe end. The content of citric acid and malic acid showed the same change in the earlystage and then kept stable. Lactic acid increased persistently. Acetic acid and ethanolincreased in the early stage and then kept stable till the end. 3) In the stater culture fermentations, Leuconostoc mesenteroides showed earlierrapid growth, while continuous decline was seen after2days. Although3lactobacillus showed later rapid growth in the early stage, their counts mainlyremained stable till the end. Leuconostoc mesenteroides showed the best utilization insucrose, however,3lactobacillus seems prefer used glucose and fructose than sucrose.It seems that Leuconostoc mesenteroides did not use fructose and citric acid. All ofthe4LAB could metabolized malic acid in the early stage. Leuconostocmesenteroides produced lactic acid only in the early stage, however,3lactobacillusproduced much more lactic acid throughout the fermentation. Leuconostocmesenteroides produce much acetic acid in the early stage, and Lactobacillusplantarum and L. zeae could produce a little acetic acid. L. casei did not producedacetic acid.