Study On The Changes Of Microbial In Pickles Preserved At Low Temperature

Pickle is a traditional fermented food, with fresh sour taste, refreshing and delicious appetizers and promote digestion, and many other advantages, deeply loved by our people. In addition, regular consumption of pickles can intake a lot of lactic acid bacteria and their fermented products, they are capable of regulating the gut microflora balance, lower cholesterol, anti-aging, anti-tumor, improve immunity and other health functions.At present, China pickles are be freshed by heat-sterilization and combined with preservatives, Pasteurization killed most of lactic acid bacteria, pickles lost some health functions, and preservatives in itself has some toxicity, especially now that there are preservatives widely used exceeded phenomenon. Along with the development of cold chain, the development of China's food cold industry is fast, the feature of cold preservation is high fresh and low nutrient loss and so on.In this paper, white radish as raw material, using vegetable juice to select fermentation Strains, studied the ratio between the strain, inoculum, salt concentration, the amount of sugar added, optimization the fermentation formula using the optimal orthogonal; By studying Microorganisms trend,Microbial changes,microbial flora changes in salinity of pickle Preserved at low temperature, as our theoretical basis for the development of pickle cold chain.The conclusions of this study as follows:(1)We choose Lactobacillus Paracasei,lactobacillus brevis,Leuconostoc mesenteroides subsp. Mesenteroides as inoculated fermentation bacteria. The concentration of salt, the amount of added pepper and Inoculum are the major factor for the impact of pH and total acid, sugar content on the effect was not significant; Inoculated pickle recipe finalized as follows:3% inoculum,3%salt concentration,4% sugar,3% pepper.(2) The number of bacterial count, lactic acid bacteria and yeast of Pickles stored at 4℃decreased in the early day,15 days to a minimum value, decreased 3,2,1 magnitudes respectively, a little increase later; the tolerance of lactic acid bacteria is stronger than the other bacterial, MPN value has been less than 3.0CFU/g, Effect of temperature on the total number of microorganisms is great,4℃is more suitable for long-term storage of pickles than 8℃and 20℃.(3)There are five Lactic acid bacteria were isolated and identificated in the first day: Leuconostoc mesenteroides subsp. mesenteroides,lactobacillus brevis,Lactobacillus Paracasei,Lactobacillus plantarum and Lactobacillus Streptococcus; There are four yeast were isolated and identificated after fermention:Candida parapsilosis,Hansenula anomala,Rhodotorula acheniorum,Brettanomyces anomalus.(4)Lactic acid bacteria of pickle Stored for 30 days in 20℃Compared with the first day, Leuconostoc mesenteroides subsp. Mesenteroides and Lactobacillus Streptococcus disappeared, There are Leuconostoc mesenteroides subsp. Mesenteroides and lactobacillus brevis in 4℃pickles, There is only Lactobacillus Streptococcus disappeared in 8℃;Yeast:there are Brettanomyces anomalus isolate frome pickle stored at 20℃,Rhodotorula acheniorum at 4℃,only Brettanomyces anomalus disappeared Compared with the first day at 8℃.(5)30 days later, there are Leuconostoc mesenteroides subsp. Mesenteroides and lactobacillus brevis isolate from 3% salinity kimchi, Leuconostoc mesenteroides subsp. Mesenteroides and Lactobacillus plantarum from 5% salinity kimchi, Leuconostoc mesenteroides subsp. Mesenteroides and Lactobacillus Paracasei from 7% salinity kimchi; Yeast:there is only Rhodotorula acheniorum isolate from 3% and 7% salinity kimchi, Rhodotorula acheniorum and Hansenula anomala isolate from 5% salinity kimchi.