| Jiangshui celery was a kind of traditional fermentation vegetables of northwest area in China. It was handed down from generation to generation for thousands years because its simple technology, special flavour and rich nutrition. It was generally recognized as healthy function food. Homologous products were sold at market in the recent years. But its processing technology depended on exchanging"starter"(strains) each other.However, it was hard to process this kind of food in modern ways due to lack of systematic reseach on its fermentation theory.In this experiment, traditional folk processing technology was investigated and summaryed. The predominant microorganism flora were isolated and identified, and the four desire strains (flora) were screened. Their fermentation characteristics were reseach, in the same time, the changing regularity of nutritional, founctional compositions and nitrite were systematically studied during Jiangshui celery fermentation. The optimum technology and production standard of Jiangshui celery was put forward based on research of Jiangshui celery processing mechanism and technology.The main results including:1.Through investigation, analysis and summary of traditional folk processing technology, the successful technology of Jiangshui celery was: celery→blanching(beforehand sterilizing)→flour or rice adhesive→open fermentation 3～5 days→products.2. The changing regularity of the preponderant population during the natural Jiangshui celery fermentation was: Bacillus subtilis, yeast, and acetic bacteria were dominant in the first stage of fermentation(1～3days),then leuconostoc. Anaerobicbacteria were the main species in the middle stage(4～7days). Acid-fast yeasts multiplied in the last period (8～9days) and produced alcohol and yeast bite if the fermentation were keeping on in the period. Ten days later, if products were not sterilized, acid-fast mold propagated and bring about the corruption of products.L1,L2,L3 and L4 strains were isolated and identified from the fermentation Jiangshui celery, and L1 was leuconostoc, L2 was lactobacillus brevis, L3 and L4 were lactobacillus plantarum.3. Flour adhesive contains much nutrient such as soluble saccharide and starch etc, which provide good conditions for microorganism growth and propagation. Found: fermentation speed and acid production of celery that added flour adhesive were higher than that of fermentation medium without flour adhesive, and the acid content in flour adhesive was nearly 2.0 times than that of fermentation medium without flour adhesive at the fifth fermentation day.4. The research found that the change of preponderant population was almost same in open and close fermentation. The obvious difference was that at early stage, the infectious microorganisms in open fermentation were more and acetic content was higher than that of closing fermentation. Therefore the lactic acid fermentation of close fermentation started slowly, but its lactic acid fermentation can last long time and the lactic acid content was high. It means that the quality of products was stable,and shelf life was long,but the mouth-feeling was inferior to the products produced by opening fermentation method.The change of preponderant population was effected by the temperature. Within 20～35℃,the fermentation speed and the lactic bacteria propagation become quicker with the temperature increasing, but the period of propagation was short. The length for preservation of products were short if products were not sterilized.However, the lactic acid bacteria growth was constrained if temperature exceeds 35℃. 25～30℃was desirable for lactic acid fermentation.5. The nitrite peak appeared in both spontaneous fermentation and inoculating fermentation, and nitrite content depended on nitrate reductase activity. The peaks of nitrite and nitrate reductase activity appeared in fermentation earlier stage. With acid content increasing, nitrate reductase activity declined gradually at pH≤4.5, meanwhile the nitrite peaks also disappeared gradually.Nitrite peak could be controlled obviously by adding flour adhesive, salt, inoculating mellow Jiangshui and proper blanching. Within 20～35℃,with the fermentation temperature enhancing, the pH decilined quickly, the nitrite peak appeared early and its value was low. Both the peak of nitrate reductase activity and nitrite content could be lowered by inoculation fermentation, no matter single strain or mixed strins were used, among these treatments, the ratio of strains L1:L2:L3:L4 = 1:1:1:1 achieved the best result. The content of nitrate in final fermentation Jiangshui celery was lower than the standard issued by FAO/WHO.6. The diluent ratio of Flour adhesive was 1:1, blanching 2～3 min, fermentation temperature 25～30℃, the pH decreased quickly and acidity was high, VB2 content and Vc conservation rate were high, but total carotene had more loss. VB2 was enhanced gradually and its content during fermentation of Jiangshui celery was 7.1times than that of fresh celery. Loss of VC was heavy during the first period of fermentation. At pH<4, VC content was stable, and VC lost for 50～60% during whole fermentation. Amino acid during fermentation was about 6 times than that of fresh celery.7. The VB2,Vc and amino acid as evaluation,the effect of different inoculating method and inoculating strains on products nutrition was obvious. The total trend was:inoculating mix strains>inoculating pure strains>inoculating mellow Jiangshui>spontaneous fermentation.The VB2 of Jiangshui celery produced by inoculating four LAB strains was 1.1times than inoculating mellow Jiangshui, Vc content was 2.45times, and amino acid was 1.6 times. Furthermore, the mouth-feeling of inoculating fermentation was better than later two methods.It was also found that nitrite and nutrition content increasing (besides total carotene decreases) were closely related to the regularity of LAB growth. While LAB increasing, the content of nitrite reduced and content of VC,VB2 and AA increased. It was showed: LAB was closely related with those materials. Through analysis of those materials, edible and safety optimum period of Jiangshui vegetables was determined.8. The mathematical model of fermentation technology was building-up by analysis of the regression orthogonal test. The optimum fermentation technology was: inoculate amount 5%, flour adhesive:water 2:1, blanching in boiling water for 3 minutes, fermentation temperature 26℃.9.The change of flavonoids was researched during fermentation. The conclusions showed: the flavonoids yield were high after fermentation and found the method of"fermentation extraction".The flavonoids yield in fermentation Jiangshui celery by the method of ultrasonic extraction was 1.4 times than flavonoids yield in fresh celery by the same method. The flavonoids yield of inoculate fermentation are higher than treatment of spontaneous fermentations.10. Through reseach and analysis on the function of flour adhesive,change regularity of predominant strains and nutrition content in Jiangshui celery, the results showed that the processing mechanism of Jiangshui celery depended on the nutrition function of flour adhesive, microorganism fermentation, protein decomposition and blanching.11.The mathematical model of storage method on Jiangshui celery was builded-up through orthogonal experiment, and the optimum preservation conditions were: storage temperature 0.5℃, benzoic acid-Na dose 0.3‰,microwave (800w)treatment 68s. Under this treatment, the nutrient contents preservation rate was high at the same time.
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