Study On The Pure Fermenting Pickles And Storage Methods Of Carmine Radish

This study based on carmine radish as raw materials. First, selected strains suitable for pure breed fermentation of carmine radish by inoculated fermentation. Second, production amount of acid and change of pH as evaluation standard, the preparation of a good starter cultures through the best proportion of mixed strains by fermentation experiment. Apply the starter culture to processing of carmine radish kimchi fermentation to study the effect of inoculation quantity, fermentation temperature, concentration of salt and sucrose content on production amount of acid and organoleptic quality. Optimize the best processing of carmine radish kimchi fermentation by response surface method. Research change tendency of various physical and chemical indicators, microbial populations, when pure breed fermentation and natural fermentation of carmine radish in the optimum fermentation condition. And detect differences of volatile aroma composition in two kinds of products by GC-MC. Finally, this paper also makes a preliminary study of the new preservation methods of pure breed fermentation pickle. Compare effects of different sterilization methods on pickle physical and chemical properties, microbial strains, influence of volatile aroma components by pure breed fermentation carmine radish. And the physical and chemical indexes, microbial strains, the change of volatile aroma composition under low temperature preservation, which provide some innovation ideas for preservation methods of kimchi industry. The conclusions were as followed:(1) The study of strain growths and fermentation test, fermentation microorganisms of carmine radish are Lactobacillus planetarium, Lactobacillus longer, Leuconostoc mesenteries, and optimal inoculation ratio is2:1:1.(2) By the response surface method, the optimum process conditions of pure breed fermentation pickle is5%inoculation quantity, fermentation temperature32℃, salt concentration4.5%, sugar content2%. For the selected four factors, the primary and secondary order of factors which affect production amount of acid of pickle is salt concentration> fermentation temperature> inoculation quantity> sucrose content. Primary and secondary order of factors which affect sensory evaluation of pickle is salt concentration> sucrose> addition quantity of> fermentation time.(3) Comparison of physical and chemical indicators and micro ecological changes of pickle brine by pure breed fermentation and natural fermentation, Which supplied pure breed fermentation can greatly shorten the fermentation time, is conducive to the preservation for vitamin c and amino nitrogen of pickle, reduction effect for nitrite of pickle is better. After7days by pure breed fermentation, Colony forming units of lactic acid bacteria is about3.78×108cfu/mL. The total cells number, mold and yeast number and coliform bacteria count are lower than that of natural fermentation during the fermentation process. The above results show pure breed fermentation has advantages including preservation of pickle nutrients, to inhibit the growth of harmful microbes, to improve the safety of pickled vegetables and health care function, etc.(4) There are73kinds of aroma substances for product of natural fermentation, including16kinds of ester substances,11kinds of alcohols substances,3kinds of aldehyde substances,8kinds of ketone substances,4kinds of acids substances,23species of hydrocarbons,2kinds of sulfur,6kinds of other substances. The content of ester and alcohol substances in natural fermentation pickle is higher, or the content of ketone and aldehyde substances in pure fermentation pickle is higher. The percentage content of hydrocarbon substances is27.3%in natural fermentation pickle, with many senior fragrant olefin substances such as1-caryophyllene, β-lam incense ene and D-cadinene. However, the percentage content of hydrocarbon substances is32.3%in pure breed fermentation pickles, which are mainly composed of alkanes. From the kinds and content of aroma substances, natural fermentation is better than pure breed fermentation.(5) The greater the microwave power or the longer the processing time, the sterilization effect is better. Combinations of different sterilization time and sterilization power can make total cells number of pickle reduce by more than5orders of magnitude, but the microwave sterilization is apt to degradate reducingVc and soft texture of pickle.With the increase of pressure or the extension of the holding time, superhigh pressure sterilization effect is better. When pressure is300MPa, the processing time is50min or400MPa, the processing time30min or more, can make total cells number of pickle reduce by more than5orders of magnitude, and can well protect the reducing Vc and brittleness of pickle, which is better than that of microwave sterilization and thermal sterilization.(6) There are73kinds of aroma substances for pure breed fermentation pickle through ultra-high pressure sterilization, including15kinds of ester substances,1kind of alcohols substance,2kinds of aldehyde substances,3kinds of ketone substances,2kinds of acids substances,26species of hydrocarbons,1kind of sulfur,7kinds of other substances. Having34kinds of aroma substances for pure breed fermentation pickle through microwave sterilization, including6kinds of ester substances,1kind of alcohols substance,5kinds of aldehyde substances,4kinds of ketone substances,1kind of acids substance,14species of hydrocarbons,3kinds of other substances. There are43kinds of aroma substances for pure breed fermentation pickle through thermal sterilization, including7kinds of ester substances,2kinds of alcohols substances,5kinds of aldehyde substances,2kinds of ketone substances,1kind of acid substance,21species of hydrocarbons,1kind of sulfur,4kinds of other substances. The results show that aroma composition of pickle has a great change after sterilization. Microwave sterilization and thermal sterilization can make aroma composition of pickle reduce, but also generate some new substances, Ultra-high pressure sterilization can add aroma components of pickle, produce many new aroma components, significantly increase the contents of ester and alcohol substances, especially.(7) pure breed fermentation pickle storaged at4℃, total acid of pickle showed a trend of gradual growth and preservation after30days, total acid pickle is up to0.875g/100g, the optimal edible period is20days. Refrigerated after20days, loss rate for reducing Vc of pickle is54%, amino nitrogen is48%, the cells number of lactic acid bacteria is5.4X107cfu/g, but lactic acid bacteria as mainly microognism of pickle still has high health care function, mold and yeast counts of pickle is2.19×103cfu/g, and descend67%relative to the initial counts.(8) There are25kinds of aroma substances for pure breed fermentation pickle after refrigeration, including5kinds of ester substances,4kinds of alcohols,14kinds of hydrocarbon, and2kinds of other substances, no aldehydes, ketones and acids substances. The original aroma compositions of pickle after refrigeration are almost lost, but also generate some new aroma chemicals, the content of hydrocarbons increased significantly from32.3%to67.61%, especially generate fragrant olefin substances such as1-caryophyllene, B-alphar Cubebene and Epizonarene, etc.