Mustard root (Latin name:Brassica juncea) is also known as kohlrabi which is cruciferous biennial herbs.kohlrabi has two kinds of species,one is native specie and the other is foreign specie.The kohlrabi which is native specie are cultivated Guangdong, Guangxi, Sichuan,Jiangsu, Liaoning and other provinces.Foreign species,botanically known as turnip greens,is from sandy coast of northern European.According to legend,the cultivation of Rome is said the earliest which was introduced into China from Siberia.Pickled mustard root has a long history in China.According to records, the Three Kingdoms Period, "Zhuge Liang ordered his soldiers to cultivate kohlrbi and said it has six benefits.Pickled kohlrabi was said in ancient books as"qing zu". In 1800 there were already commercial production.In this study, Fengjie kohlrabi natural fermentation process quality as an investgating object,by measuring and analyzing the separation,cultivation,calculation and classification of microorganisms.The paper tends to exploit the bacteria form,the changing principle of the bacteria family and the major microorganisms in kohlrabi ferment system.Based on tendency analysis on traditional kohlrabi spontaneous fermentation,we should study the major microorganisms and their performance in kohlrabi production.In this study, To improve the quality of kohlrabi, reduce processing cycle, explor of modern processing.suitable preparatory culture of kohlrabi production was researched and used.Test results are as follows:1.There are bacteria which were selected from natural fermented mustard root(pickling by wind and pickling by salt):Pedicoccus halophilus, Bacillus sphaericus, Bacillus cereus, Bacillus subtilis, Leuconostoc msenteriodies, Streptococcus lactis, Streptococcu faecalis, Bacillusstearothermophilus, Lactobacilluslactis, Lactobacillushalotolerans, Lactobacillus fermentum, Lactobacillus plantarum.2.There are yeasts which were selected from natural fermented mustard root(pickling by wind and pickling by salt):Saccharomyces rouxii,Hansenula anomala,Debaryomyces hansenii,Torulopsis versatilis,Rhodotorula minuta,Saccharomyces cerevisiae,Saccharomyces globosus3.There are yeasts which were selected from natural fermented mustard root(pickling by wind and pickling by salt):Penicillium and Aspergillus.4.The strains with best potential as kohlrabi starter culture were Leuconostoc mesenteriodies,Lactobacillus plantarum,Lactobacillus lactis.To get a better fermentation technology,the three kinds of bacteria were used as fermentation strains,with different inoculation amount,inoculation for ratio,salinity,water content,temperature and vacuity in and orthogonal experimental design and sensory evaluation test.A sequence that indicates the importance of different factors was got,that is,inoculation for ratio>temperature>salinity>inoculation amount>water content>vacuity. (A>F>C>B>D>E) The optimal combination of fermentation is A4B2C5D2E2F3, the inoculation for ratio:Leuconostoc msenteriodies:Lactobacillus lactis:Lactobacillus plantarum=3:1:1,3% inoculum, containing12% salt,water content of 60%, vacuum of 0.08MPa, the fermentation temperature is 30℃.Kohlrabi in the 30d or so, we can achieve 0.84% lactic acid, which naturally fermented lactic acid content of mature kohlrabi.The standard of kohlrabi is not only the mature content of lactic acid, but aslo sensory evaluation.So the kohlrabi need about 40 days to achieve the best state.5.The change rules of sensory indexes and physiochemical indexes for artificial inoculation and natural fermentation(picking by salt and picking by wind) during kohlrabi fermentation were studied.About 40 days of artificial fermentation kohlrabi in flavor, color, taste, brittle with natural fermentation for 90 days appeared similar sensory kohlrabi, and no significant difference in the final product, while the artificial one was able to greatly shorten the fermentation time.Artificial fermentation of nitrite content is lower than natural fermentation.This shows that the artificial fermentation, although the flavor and the quality were no significant improvement, but the artificial one can speed up the fermentation and shorten the fermentation time and production cycle. Kohlrabi can not only reduce production costs, but to improve the security of it. |