Selection Of Raw Material Sichuan Mustard Pickles(Brassica Juncea) And Quality Analysis Of Fermentation And Storage Period Process

Pickles is traditional lactic acid fermented foods in our country,Sichuan pickles is representative of China pickles. Sichuan pickles have rich source of raw materials. Mustard(Brassica juncea) is a nice raw material of Sichuan pickles,the pickles is delicious, flesh juicy,and is Consumer table delicacies. At present, the pickle production enterprises use more natural fermentation or high salt production in the form of pickled products, The disadvantage is needing a long fermentation cycle, nitrite content is higher and the quality is not stable. The sterilization technique of enterprise is single, cause quality of products is not stable in circulation process, partial product have exceed preservative. This article through to5kinds of mustard with direct vat set fermentation to screening quality sichuan pickles raw material, and using raw material with different fermentation. Analyse quality change in fermentation process, use different sterilization treatment, researching changes of quality in the storage process.The results as follows.1. Throuhg to fermenting5kinds of mustard(Brassica juncea) with direct vat set fermentation. Assaying total acid, soluble sugar, raw materials and finished products, hardness, crude fiber and other physicochemical index of raw materials and finished products and assaying the volatile flavor substances of product simultaneously doing sensory evaluation, in order to screen out quality bubble green vegetables. The result of Least-Significant Difference(LSD) show that the total acid, moisture, soluble sugar and crude fibre are similar between Q70and Q5.The quality of different pickles have significant difference. Raw material of pickled for Q123in Vc, moisture content, total acid, chlorophyll, hardness is superior to the other4kinds of vegetables too (P<0.05).The5kinds of mustards are suitable to serve as raw materal of pickles. Moisture content was lower than90%, total acid is0.52%,Vc content high, colour and lustre is golden yellow, brittleness is good, flavor composition is rich in raw material of pickled for Q123(B.juncea.var.utilis.Li), the quality is much better that the other pickles,considered pickles of high quality raw materials.2. High quality raw materials Q123(B.juncea.var.utilis.Li)were used natural fermentation、direct vat set fermentation and aged brine fermentation.Assaying the fermentation process of physicochemical index, microbial index, and the finished product volatile flavor components were determined simultaneously doing sensory evaluation. The results of sensory evaluation of direct vat set fermentation and aged brine fermentation is better at the beginning of the fermentation.The pickle with direct vat set fermentation is golden color, crisp and refreshing, sensory evaluation score is the highest, followed by aged brine fermentation. LSD of sensory evaluation shows that the3kinds pickles of different fermentations have significant difference(P<0.05). The pickle with direct vat set fermentation in the nitrite, Vc, colour and lustre is superior to the aged brine fermentation, two kinds of fermentation way pickles detect the volatile flavor substances respectively for91and92species, including the same component52species, but each component relative content exist certain differences. Natural fermentation pickles have81species volatile flavor substances.The main volatile flavor substances have ester, alcohol and hydrocarbon, the isothiocyanate is most important volatile flavor substances. The quality of pickle with direct vat set fermentation is better in three kinds of pickles, slightly better than the aged brine fermentation, quality of pickles with the two ways fermentation production is better than natural fermentation.3. Using vacuum packaging to pickles product then90samples are divided into5groups according to the experiment needs. and respectively by means of thermal, preservative, ultrahigh pressure, thermal+preservative, thermal+ultrahigh pressure and5of sterilization treatment at room temperature storage after6months. Assaying physicochemical index, microbial index, simultaneously doing sensory evaluation, analysis in the storage process quality changes. The score of sensory evaluation showed that the preservative treatment of bubble vegetable corruption, at this point, the sensory score the lowest after6months storage.The result of LSD shows that quality of pickle with preservative treatment is significant lower, the score of sensory evaluation is similar between thermal+preservative and thermal+ultrahigh pressure. The result of physicochemical index shows acid content of preservative exceed1.5%after6months storage, high pressure total acid content is0.8%. Nitrites are tending to decline. Thermal+ultrahigh pressure and thermal+preservative sterilization effect is good, storage process microbial quantity change is not significantly. After six months after storage, preservative processing sample quality of a material soft rotten, there is corruption taste, so in addition to chemical treatment outside the rest sterilization pickles shelf life are more than six months.This article use large holder for fermenting, this way is close to the actual production of enterprises, the research for raw materials screening, fermentation methods and antiseptic sterilization treatment is systematically. Research results can provide reference for raw materials screening of Sichuan pickles, improve ferment production and mending antiseptic sterilization method to improve the stability of products in shelf life.The result of this article has theoretical significance and practical application value.