Effects Of Cold Chain Temperatures And Irradiation On The Quality And Biochemical Characteristics Of Salmon And Large Yellow Croaker

China is a large aquaculture nation,however,due to the low utilization rate of cold chain,the phenomenon of "break chain" often appears,which affects the quality of aquatic products and causes a lot of economic losses.The research materials of this paper were salmon and large yellow croaker.Indicators like APC,TVB-N were measured to construct the corresponding prediction model of shelf life and remaining shelf life.These models could monitor the quality of aquatic products in cold chain.At the same time,electron beam irradiation technology was used to deal with salmon and large yellow croaker.The effect of irradiation and the optimal irradiation dose was determined by measuring the quality and biochemical characteristic of them.The main results were as follow:1.By storing fresh salmon at different temperature,the shelf life prediction model(1)and remaining shelf life model(2)could be obtained:SLT = 6.78/Exp(30.7-8399/T)(1)(?)The relative error of shelf life prediction model and remaining shelf life model were-6.45%and 9.41%respectively.The results showed the models could predict the shelf life and remaining shelf life of salmon at different temperature.2.Ice fresh salmon was irradiated by an electron beam sourse of 0 kGy,0.5 kGy,1 kGy and 2 kGy respectively to evaluate the effect of electron beam irradiation on the quality of salmon.The results showed that the total viable count and tatal volatile basic nitrogen was inhibited after irradiation.But 1 kGy and 2 kGy accelerated the oxidation of fat,produced a variety of volatile substance of aromatic hydrocarbons,aldehydes or sulfides,and made the color of salmon dim.So 0.5 kGy was the optimal dosage to preserve salmon.3.By storing large yellow croaker at different temperature,the shelf life prediction model(3)and remaining shelf life model(4)could be obtained:SLT=11.30/Exp(34.30-9359/T)(3)(?)The relative error of shelf life prediction model and remaining shelf life model were-13.21%and 3.6%respectively.4.Large yellow croaker was irradiated by an electron beam sourse of 0 kGy,1 kGy,2 kGy and 4 kGy respectively to evaluate the effect of electron beam irradiation on its quality.The results showed that the total viable count and tatal volatile basic nitrogen was inhibited after irradiation.But 4 kGy accelerated the oxidation of fat.There was no siginificant difference between the irradiated group and non irradiated group with the increase of storage time and temperature fluctuation.Irradiation could decrease the content of alpha helix,total sulfhydryl and the activity of Ca2+-ATPase of myofibrillar protein,but SDS-PAGE eletrophpresis could't show the difference among the groups.In conclusion,2 kGy was the best irradiation dosage for the preservation of large yellow croaker,and it could slow down the bad influence caused by temperature fluctuation during storage.