Based On The Technique Of PCR-DGGE Fingerprint Analysis Research On The Effects Of Different Low Temperature Preservation Method On The Quality Of Squid

Zhejiang province is a big province of fisheries.Aquatic product total output value accounted for one tenth of national total output value,the comprehensive production capacity ranked fourth in the country,But the development of aquatic products trade has been seriously impacted due to the high moisture and protein content of aquatic products,which make them easily lose freshness,and get spoiled rapidly.Therefore,it is particularly important to strengthen the research on the methods of preservation of aquatic products.Especially in today’s high aquatic products consumption world.We choses squid as a research material.We uses PCR-DGGE technology to compare squid quality change under different low temperature preservation methods.The study is to explore the reasons why the squid quality deterioration at different low temperature storage technology.We then use these reasons as the basis to develop a new,operable and cost efficient low temperature preservation technology,which suitable for squid and other aquatic products.First,the frozen thawing method,tissue homogenate and shaking method three kinds of method to deal with the squid samples,using SDS method combined with protease K method directly to the squid organization of bacterial genomic DNA extraction,established a set to suit the squid organizations in colony structure analysis method.The results showed that the homogenate extraction of DNA of the highest yield and table processing times,freeze thawing extraction of DNA of the lowest yield and three treatments of PCR-DGGE results without obvious effect,by sequencing in corruption squid in the main dominant bacteria Pseudomonas sp.,Photobacterium phosphoreum and Shewanella sp.Secondly,the reaction surface analysis method was used to adjust the ascorbic acid,sorbitol,sodium chloride and calcium chloride as freezing point regulators of squid ice temperature preservation.Combined with PCR-DGGE fingerprinting technology,we screened ascorbic acid,sorbitol,Sodium,calcium chloride can effectively reduce the freezing point of squid,but also significantly inhibit squid flora propagation,play a certain role in preservation.Finally,the use of sodium chloride,calcium chloride,sorbitol,ascorbic acid four soaking liquid combination as regulators of ice temperature preservation method,and cold water preservation,conventional micro freezing,freezing preservation method and comparison of fresh squid.Through chemical analysis of cold preservation,changes in sea ice temperature preservation,micro freezing preservation and freezing preservation under the condition of four kinds of squid nutritional components,the total number of colonies,TVB-N,histamine,p H value,water holding capacity,sensory,comparison of four dominant bacteria under the condition of fresh squid changes with PCR-DGGE fingerprint analysis,comparison of four kinds of fresh preservation methods,show that the ice temperature preservation,micro freezing preservation and freezing could effectively inhibit the growth of microorganisms in squid,the increase of TVB-N value and p H value of histamine,and increased water holding down.Especially by regulators in the squid and ice temperature conditions,cold water storage can prolong the storage period of nearly 10 days,other than the micro freezing preservation and freezing can effectively maintain the nutrition,especially in water,that ice temperature preservation can effectively keep the original flavor.Based on PCR-DGGE technology,the effects of squid in different low temperature and the causes of corruption were analyzed,and the fresh keeping technology of squid industry was improved.It can also provide theoretical guidance for improving the quality of squid products.