Dynamic Study Of Quality Variation Rule Between The Natural Fermentation And Artificial Inoculation Process Of Kimchi

As a traditional popular food in China, kimchi, it has many advantages: easy tomanufacture, simple equipment, low cost, rich nutrition, delicious and crisp, convenient forfeeding, can be processed during four seasons etc., it is the favorite of consumers. Kimchi isrich in lactic acid, with appetizers, a dietary aid, enhance the effect of nutrition and immune.Most of the traditional kimchi are mainly natural fermentation of the workshops, although thearoma of natural fermentation kimchi is more concentrated, pure taste, but the fermentationconditions is difficult to control, product safety and quality are hard to protect, and is notsuitable for modern industrial production, so, reserchers gradually began to study the processof artificial inoculation fermentation of kimchi. This topic investigate all aspects of the qualitybetween the natural fermentation and artificial inoculation kimchi, including thedetermination of the sensory texture, salt, total acid, soluble sugar, reducing sugars, vitamin C,amino acid nitrogen content and amino acids, organic acid content and aroma components,make a comparative analysis of two fermentation quality change, draw the followingconclusions:(1) Measured the texture of cowpea by using TA-XT2i texture analyzer, preferred thetest parameters out of the bubble cowpea texture: test rate is2.0mm/s, the force size is5.0gand the amount of compression to30%. All bubble cowpea texture index are significant, thetrend of the sensory evaluation and texture data are basically the same, inoculation thannatural fermentation of bubble cowpea texture changes quickly.(2) The total acid content of the kimchi gradually increased with the prolongation of thefermentation time; total sugar, reducing sugar, amino acid nitrogen content declined with time;kimchi products are rich in flavor amino acids(sweet, bitter, umami, sour), and contains eightessential amino acids which are must for the human body; amino nitrogen and vitamin Ccontent of artificial inoculation kimchi are higher than the natural fermentation kimchi.(3) After compared the flavor substances extraction methods, using simultaneousdistillation and extraction method to determine the flavor compounds in kimchi,chromatographic conditions: the column was a fused silica capillary columnRtx-wax(30m×0.32mm×0.25μm); GC: temperature programming, the initial temperature is40.0℃, retained2.0min, temperature up to100.0℃to5.0℃/min rate, then temperature up to250.0℃to10.0℃/min rate,retain3.0minutes. Inlet temperature is250.0℃, injection volumeis1.0μl, split ratio is30:1, carrier gas is high purity helium, the column flow is1.00ml/min,carrier gas pressure is35.7kPa. MS: interface temperature is250.0℃, ion source temperatureis230.0℃, scan range is35-450m/z, electron source is El, electron energy is70ev, scan rate is0.5s/scan. the main aroma components of the Kimchi, including a total of seven kinds ofvinyl compounds, alcohols, esters, ethers, aldehydes,sulfur compounds and alkane compounds.The organic acid content of artificial inoculation kimchi changes quickly, and higher than thenatural fermentation.(4) The sensory of artificial inoculation kimchi products consistent with the naturalfermentation, the conventional quality of artificial inoculation fermentation of kimchi, saltcontent, total sugar, reducing sugars, vitamin C, amino acids, amino nitrogen, total acidchange faster than the natural fermentation, Artificial inoculation of the fermentation ofkimchi are matured in a relatively short period of time, and the various indicators are or lessthe same with the naturally fermented pickles; material types and quantities of artificialinoculation fermentation of kimchi flavor are close to the natural fermentation.