Pollution Investigation Of Common Mycotoxins In Aquatic Products And Risk Assessment Of Residues In Shrimp

Mycotoxin is ubiquitous and a class of secondary metabolites produced by fungi.Mycotoxin generally has strong toxicity.Human and animal will have the acute or chronic poisoning symptoms and carcinogenic,teratogenic and mutagenic damage after absorbing them.O n the basis of the pollution status of common mycotoxins in feed,the purpose of this study is that analysizes the residues risks of common mycotoxin in Litopenaeus vannamei and finds out the main risk factors and its health risk providing important theoretical support for the safety of shrimp food.This study mainly has the following aspects:1.A synchronous detection method of four mycotoxins in shrimp and dried aquatic products by LC-MS/MS.A synchronous quantitation of T-2,AFB1,DON and OTA together in shrimp and dried aquatic products by LC-MS/MS was established.It uses acetonitrile / water(84/16)as the extraction solvent and degreases with hexane in the extraction in 60 min and 25 ? to extract mycotoxins and then chooses.30 % methanol-water(3+7,V+V;including 0.1 % formic acid in 5 mmol/L ammonium acetate)as mobile phase,ESI+ / ESI-alternate as scanning mode to determine them.Because matrix will affect detection of mycotoxins,using matrix matching standard curve quantitatively can weak the matrix effect.Under the optimized conditions,this method is simple,rapid,accurate and precise,be ing suited to the determination of four mycotoxins in shrimp and dried aquatic products.2.Investigation of mycotoxin contamination in dried aquatic products.This method was used to detect mycotoxin contamination of dried aquatic products from the market.The results showed that mycotoxin contamination is widespread coexisting two or more mycotoxins in dried aquatic products in Zhanjiang and its pollution rate was up to 53.85 %.Among them,the pollution of AFB1 and OTA was more common and T-2 pollution was relatively a few,whereas DON has not been detected at present.Furthermore,the pollution in fish products was most serious,then was shrimp,and the last was shellfish products.3.Hazard identification and description of mycotoxin accumulation in shrimp.Shrimp was raised with the feed including AFB1,T-2,DON or OTA for 20 days.Growth status of shrimp was taken down,made and observed the tissue pathological,and detected the mycotoxin residues in shrimp.Then,the rats` body weight,index of blood and serum,sperm deformity rate and bone marrow micronucleus rate was detected after they were fed with homogenate of shrimp muscle.It shouwed that Four toxins could increase the mortality rate of shrimp whereas decrease their rate of survival,weight gain and specific growth.The histopathological lesion of shrimp was more serious with increasing mytoxins showing the damage of myofiber and sarcomere and the increasing,fracturing or dissolving spatium intramusculare.Mycotoxins can accumulate in the shrimp tissuesbecause of the increasing mycotoxins residues in shrimp muscle which caused rats` growth retardation,weight loss and the damage of immune system,hematopoietic system and heredity.4.Exposure assessment and risk characterization of four mycotoxins in shrimp.The quantitative exposure assessment of mycotoxins by means of shrimp dietary consumption was conducted with the application of @ Risk 7.5 software basing on Monte Carlo simulation.The study found: the average daily intake of T-2 via shrimp consumption in China was 1.92 ng/kg·bw·d,the median was 1.76 ng/kg·bw·d and the 95 percentile was 2.24 ng/kg·bw·d;the average daily intake of AFB1 was 0.42 ng/kg·bw·d,the median was 0.42 ng/kg·bw·d and the 95 percentile was 0.50 ng/kg·bw·d;the average daily intake of OTA 1.41 ng/kg·bw·d,the median was 1.30 ng/kg·bw·d and the 95 percentile was 1.65 ng/kg·bw·d;the average daily intake of DON 2.53 ng/kg·bw·d,the median was 2.31 ng/kg·bw·d and the 95 percentile was 2.98 ng/kg·bw·d.Mycotoxin exposure of the city residents are higher than that of rural residents,at the same age,the exposure rate of female was higher than that of male.The level of exposure decreased with age,but above the age of 60 will be slightly higher.The exposure of children and adolescents(3-17 years old)is higher than that of adults(aged ? 18).Risk assessment of mycotoxins in shrimp based on the exposure assessment.The study showed that the health risk generally intaking T-2,DON and OTA were small through eating shrimp.But AFB1 toxin can lead to cancer which still was less than the national average.It is suggested that the limit standard of T-2 in shrimp was 100 ?g/kg,OTA was 5 ?g/kg and DON was 1000 ?g/kg whereas the situation of AFB1 is complex and its limit standard was not evaluated.