Develop Product Of Kelp By Lactic Acid Fermentation And Study On Changes Of Microbial Flora During Storage

The kelp (Laminaria japonica Aresch), another name is Kombu, it's one ofbrown seaweed and called "Sea vegetable".The kelp contains so rich functionalmaterial and rich in nutrition that be named as "The treasure house of human nutritionelements".It is recognized as the health food and longevity dish in world.This article researched mixed lactobacillus starter by Lactobacillus plantarum,Leuconostoc mesenteroides and Lactobacillus brevis which was used to ferment kelpfor developing one new food—kelp pickle. Then using Ordinary PCR took apreliminary analysis of major corruption bacteria in kelp pickle. The changes ofmicroorganisms during the storage period were explored when the kelp pickle waspacked by different methods.The major achievements and results were concluded as follows:1.For Lactobacillus plantarum, Leuconostoc mesenteroides and Lactobacillusbrevis could adapt to the fermentation environment as soon as possible and rapidferment kelp,choice culture medium kelp juice＋peptone＋glucose was the threestrains' inexpensive expanded growth culture medium．2. The influence of the bacteria proportion between Lactobacillus plantarum,Leuconostoc mesenteroides and Lactobacillus brevis to fermenting kelp was studied.The results showed that the pH and total acid content of inoculated fermentation weresignificantly higher than that of natural fermentation, inoculated fermentation greatlyreduced pickle mature period. When the proportion of three bacteria (Lactobacillusplantarum, Leuconostoc mesenteroides and Lactobacillus brevis) was1:2:3,1:3:2,3:1:2and3:2:1, the total acid content was high and the difference was notsignificant. Analysis the total acid content, these proportions could be selected asmixed lactobacillus starter to ferment kelp.3. Fuzzy mathematics comprehensive evaluation method was applied to in thisstudy. The model of fuzzy comprehensive evaluation was established to do sensoryevaluation of the kelp pickles. The results showed that: when the bacteria proportionof mixed lactobacillus starter was1:3:2, ie, Lactobacillus plantarum: Leuconostocmesenteroides: Lactobacillus brevis=1:3:2, the A value of inoculated fermentationkelp pickles was0.8084.Combined with kelp pickles total acid analysis, andultimately select the bacteria proportion of1:3:2as a mixed lactobacillus starter offermenting seaweed.4. The influents of the fermentation temperature, the inoculation amount, saltconcentration and white granulated sugar concentration on the total acid content of thekelp fermentation were studied.The white granulated sugar concentration was nosignificant effect on the total acid content,when the concentration was in6%, the tastewas better.Select the factors that have significant effect on the total acid content ofkelp pickles (fermentation temperature,inoculation amount, salt concentration andfermentation time) to carried out the orthogonal test,comprehensive consideration ofthe total acid content and the results of sensory evaluation,through the verificationtests to determine the best fermentation process conditions:fermentation temperature 30℃, the inoculation amount3%,salt concentration4%, fermentation time4days, thesugar concentration6%. Total acid content of the products obtained up to6.29g/kgand A value of sensory evaluation was0.9417. The product color is clear, acid, saltyand delicious, sweet moderate, crisp, and has the unique fermentation fragrance offermented products and the flavor of kelp.5. Ordinary PCR technique was used to analyse the main spoilage bacteria thatcaused corruption by the conventional packaging at room temperature. By sequencecomparison, we got: the main spoilage bacteria were Bacillus cereus and Bacillusthuringiensis.6. During storage (30d), at room temperature (25℃) and low temperature(0⁴℃),non-lactic acid bacteria and lactic acid bacteria changes of kelp pickles were studied.The results showed that: the impact of temperature on the non-lactic acid bacteriasignificant difference, while no significant effect on lactic acid bacteria.7．The impact of the modified atmospHere packaging (O₂/CO₂/N₂) to the maturekelp pickles during storage period at low temperature conditions (0⁴℃) wereexplored, and compared with the vacuum packaging and the general packaging (airinflatable). The results showed that: different packaging form of kelp pickles have avery significant impact to non-lactic acid bacteria and lactic acid bacteria. The use ofmodified atmospHere packaging can effectively inhibit the growth of Bacillus cereus.