Study On Microbiological Analysis And Bioprocessing Technologies Of Capsicum Chinense

Capsicum chinense is a local chili planted in Hainan, which has rich nutrient, goldencolor and high spicy. With the increasing of life rhythm and pressure, a spicy-loved crowd hasincreased dramatically, and the prospect of special spicy foods becomes broader. Thetraditional pickling method, namely pickled with salt in high concentration, istime-consuming and unstable, and the product quality is various due to the change of theworking condition, including browning and softening, which greatly hinder the developmentof industry. In this study, the reason of browning and softening of Capsicum chinense wasanalyzed, andmicrobial processing technology was used to process Capsicum chinense andcontrol browning and softening, which aimes to improve the quality of Capsicum chinenseproducts.Microorganisms of Capsicum chinense were isolated and indentified, and the diversitywas analyzed. The traditional isolation method was used to isolate strains, and11strains werescreened, which were identified as Lactobacillus sp.（3strains）、Bacillus sp.（5strains）、Pseudomonas stutzeri、 Serratia rubidaea、 Pichia.pastoris based on physiological andbiochemical identification and sequence analysis of16S rDNA or18S rDNA, respectively.Six bands’16S rDNA gene sequences were detected in Capsicum chinense by PCR-DGGE.Lactobacillus sp. was in a dominant position which is65%of the total microorganisms, andPseudomonas stutzeri is in a secondary position which is16%of the total microorganisms.Bacillus sp.、Pseudomonas stutzeri、Serratia rubidaea can hasten browning and softening.Microorganism has a direct influence on the browning and softening.Browning and softening of Capsicum chinense and the solutions have been studied. Theresult showed that the browning is enzymatic browning and Polyhenol Oxidase （PPO） is themain enzyme. Softening happened when the rigid organization such as pectin washydrolysised. Further studies have shown that the optimal reaction temperature of PPO is40℃, and the optimal reaction pH is about6.2. A low concentration of citric acid, Vc,cysteine hydrochloride can well inhibit the activity of PPO. NaHSO3and EDTA have a verylow effect in inhibition. Ca²⁺can rebuild the rigid organization of tissue, and a lowconcentration of Ca²⁺was beneficial to the hardness-maintain. An orthogonal experiment wasdesigned to get an effective method to control browning and softening, and the optimumformula of color-protection and hardness-maintaining was Vc0.35%, Citric acid0.2%,Cysteine-hydrochloride0.02%, CaCl20.3%.The bioprocess technology was studied to process Capsicum chinense. Considering theacid-producing ability and nitrite degradation capacity, Lactobacillus sp was proved to be theoptimum strain. The result of orthogonal experiment showed that the most important factor to bioprocess was temperature, and followed with inoculation and the components startes.Adding12%salt could inhibit the residual microorganisms, enhance the taste, and slow downthe browning and softening, improving the whole quality. In general, the optimum bioprocessCapsicum chinense is as follows: blending the fresh chopped Capsicum chinense withcolor-protection and hardness-maintaining, then inoculating3%starters （Lac. E2: Lac.M1=1:1）installing at25°C for20-24h, then inoculating12%salt to inhibit the residualmicroorganisms.