The Degradation Of Ultraviolet And Electron Beam Irradiation On T-2 And AFB₁ Toxin And Its Application In Two Dried Fishes

In the storage of dried fish,it is easy to be affected by storage environment and its process to produce nitrosamines and mycotoxins,which is the main inducer of cancer.However,the control of mycotoxins in dried fish is rarely reported.Therefore,it is of great theoretical and practical significance to promote the sustainable development of dried fish industry in our country.Fusarium toxin and aflatoxin are representative and harmful belonging to mycotoxins which are secondary metabolites produced by the fungus.The experiment selected AFB1 and T-2 as the research object,ultraviolet(UV)irradiation technology and electron beam(EB)irradiation technology as the degradation technique,dried golden pomfret and dried red fish as the application matrix,so this study could be divided into two parts:The first part is UV irradiation technology.Firstly,this experiment determined the influence of different factors on the UV irradiation technology of AFB1 and T-2 by single factor experiment.Then,the optimal conditions of AFB1 and T-2 UV irradiation in standard solution were studied by response surface analysis.Finally,under the optimal UV irradiation conditions,the application had been to the dried golden pomfret and dried red fish and the effect of UV irradiation on their quality was studied.They can be concluded as follows.Firstly,T-2 could not be degrade,but AFB1 was degraded effectively by the UV.Then,the effect of different factors on the AFB1 is different: 365 nm is the most effective degradation wavelength;with the shorter distance and the longer time of irradiation,the better the degradation effect;its degradation works best with non-pure solution(methanol aqueous solution)as solvent;there was no significant difference(P>0.05)between the initial concentration and p H value.Secondly,after the analysis of Design Expert software,it was found that the optimum conditions for UV irradiation of AFB1 were 254 nm,20 min,3 cm and 60 ng/m L toxins under the existing UV conditions.The AFB1 degradation rate in dried fish was not as high as the standard solution,and that of dried red fish was higher than that of golden dried pomfret.Third,the best AFB1 UV irradiation(254 nm,20 min,3 cm)did not have a significant effect(P>0.05)on the quality of dried fish.The second part is electron beam irradiation technology.This experiment used different doses of EB irradiation to degrade AFB1 and T-2 of standard solution and dried fish(dried golden pompano and dried red fish),and explore the effect of EB irradiation on the quality of dried fish.It could draw the following conclusion: Firstly,the degradation of T-2 and AFB1 in the standard solution is significantly different(P>0.05)in the specific irradiation dose(the T-2 irradiation dose was 0,8,16,32,64,128 k Gy,and the AFB1 irradiation dose was 0,1,2,3,4,5 k Gy).Secondly,the toxin degradation in the methanol aqueous solution was significantly higher than the other two(P<0.05);with the low relative irradiation dose,the sequence of T-2 degradation rate was p H 5 <p H 7 <p H 9 and that of AFB1 was p H 9<p H 5 < p H 7;the p H value of the solvent has no significant effect on the irradiation degradation at high irradiation dose,neither do the initial concentration(P>0.05).Thirdly,the degradation trend of T-2 and AFB1 between the dried fish and standard solution was the same basically;the degradation rate is different under the same irradiation dose(the standard solution > dried golden pompano > dried red fish).Fourthly,the influence of electron beam irradiation dose(up to 128 k Gy)has some fluctuations in the quality of dried fish,but the difference is not significant(P>0.05).