Study On The Preservation Methods Of Chilled Freshwater Fish Cutting Products Based On The Growth Control Of Microorganism

Being healthy,convenient,nutritious characteristics,chilled freshwater fish cutting products has become the mainstream of the market.However,the cold fresh water fish is susceptible to corruption and secondary pollution in production and processing,so the shelf life is short.Grass carp was used to analyzed the chilled pork microorganisms in the laboratory Prophase research.The results showed that pseudomonas were the dominating bacteria for microorganisms spoilage and gives a further study on its growth pattern.Based on this study to carry out fresh chilled pork products research technology is not only research needs but also cold fresh products division freshwater fish market needs.In this paper,the total number of colonies and Pseudomonas as the target bacterias,microorganisms as the main evaluation indicators and combined the value of sensory and TVB-N to carry out chilled freshwater fish cutting products preservation techniques research.From conditions of MAP packing?reduced bacteria treatment?Selected Preservatives and Optimization of preservative additives,and then built an effective cold fresh fish preservation technology solutions,and determine the shelf life of products under different preservation program.The results obtained are listed as followings.We studied the effects on microorganism under different Modified Atmosphere Packaging and finally choose the packing method was 50%CO2+50%N2.To research chemical and physical Pre-treatment method influence on incipient total bacterial count of cold fresh gas.The results showed that the optimal sterilization condition of sodium hypochlorite were determined to be 0.3g/l for 5min and solid to liquid ratio 1:5.The percent reduction of bacteria of colony lump-sum and Pseudomonas bacteria were 83% and 81%.Comparing single and composite ways of reducing bacteria,the latter is no significant increase in the rate of reduction of bacteria,and the former processing is complex,bad tissue appearance after soaking in solvent.Consequently we choose chloros as the best pretreatment method.Fresh belly of grass carp dealt with 17 kinds of preservatives which have better antibacterial effect on Pseudomonas under filter system.Then the influence on color,flavor,morphology and tissue elasticity of product by preservatives were assessed through our senses.The findings suggested that gallic acid,citric acid,tannic acid,trimethyl phosphate,polylysine,phytic acid could keep grass carp with normal color,original flavor,good morphology and elasticity.The quality change of grass carp with the preservatives during the storage period was assessed.The first level model of microbial growth was constructed based on microbial growth curve.The bacteriostatic activity of preservatives were quantitated by parameters of model.The research shows that ?-polylysine is the best preservative to grass carp.It has a little influence of quality of grass carp than other fresh-keeping agents and a better antibacterial property.The shelf life of fresh grass carp with ?-polylysine and under modified atmosphere package(50%CO2 + 50%N2)was tested.The result shown that the shelf life of fresh-cut fish belly processed by ?-polylysine with modified atmosphere package can up to 13 days when storaged at 4?,that means,?-polylysine can maintain the fresh-cut grass carp a longer shelf life.In order to improve the preservation effect,Futher research on the effects of shelf life after deal with additives of ?-polylysine.The research shows that glycine?acetic acid?citric acid have showed good synergistic antimicrobial effect with ?-PL,significantly enhanced the antimicrobial activities of ?-PL.Then the selected auxiliary additives and ?-PL combined used in fish matrix.The result shown that the shelf life of fresh-cut fish belly processed by 0.5%?-pL with 0.2% acetic acid or 0.5%?-pL with 1% glycine is 9 days while processed by 0.5%?-p L with 0.1% citric acid can up to 11 days during storaged at 4?,choose 0.1% citric acid as the perfect additives of ?-polylysine.Through the researches on belly processing methods,which have the influence on the changes of micro-organisms during the fresh cold storage,the fact is that the optimal processing technology is to divide it into belly,and pack with modified atmosphere package after the opening film of the cleaning sheet herring,pre-cooling,reducing bacteria processing,preservation and processing aids.Combine each of the preservation methods to test the belly shelf life of products with different groups.The result shows that different treatment can be formed to four kinds of shelf life.And the four kinds are 5d,8d,9d,10 d.Examine the effect of different factors on product shelf life,the result shows that different sources had no significant effect on the shelf life of the product belly but different temperature on the belly of the shelf life of products.and 0? can push the shelf life of the product to 15 d,which is 5d longer than 4?.