Screening Of Aflatoxin B₁ Removal Strains And Reseach Its Removal Mechanism

Aflatoxin B₁?AFB₁?belong to the group ? carcinogens which could cause serious food safety problem that need to be controled.Edible fungus can effectively eliminate heterocyclic pollutants.So firstly,this paper compare the differences desorption of AFB₁ by common edible fungus and screened Auricularia auricular,a kind of edible fungus can effectively adsorbed AFB₁,then lucubrate the adsorption properties and adsorption behaviors,and finally evaluated the strains desorption effect of AFB₁ from the two aspects of in vivo and in vitro,provided a theoretical basis and technical support to control the pollution of AFB₁ in food.The main research contents and results are as follows:1.Auricularia auricula,a kind of edible fungus can effectively eliminate AFB₁,was screened by solid and liquid cultivation.The fungi can eliminate88.16% AFB₁,Further study found that the fungi,extracellular material and intracellular substances can eliminate 58.4%,13.1% and 58.4% AFB₁,respectively.The eliminate effect of AFB₁ can increase when the fungus undergo high temperature and high pressure,repeated freezing and thawing,freeze drying process,and significant decrease after ethanol wall-breaking treatment,which showed that adsorbing was the main way to eliminate AFB₁ by Auricularia auricula.For figuring out the adsorption situation of AFB₁ in Auricularia auricula,the adsorption effect of AFB₁ by cell wall and protoplast of Auricularia auricula was studied and result showed that cell walls can eliminate 63.2% toxin,and protoplast can eliminate 21.9%,which showed that main effect sites was the cell wall.The rough surface structure of cell wall and polysaccharideand on the cell walls provided conditions for adsorption reaction.2.Using the single factor experiment analyzed the factors affecting of AFB₁ adsorbed by Auricularia auricula,then through the response surface model optimized the best condition of AFB₁ adsorbed by Auricularia auricula,and the stability of Auricularia auricula-AFB₁ combination in 7 kinds of solvents were researched.The results showed that:?1?Adsorbed AFB₁ by Auriculariaauriculawas saturated when the initial AFB₁ concentration is 400 ng·mL^-1;Heating under 30? was beneficial for adsorbed AFB₁ by Auricularia auricula.Extending the time of adsorption will increase the adsorption quantity of AFB₁ adsorbed by Auricularia auricula,balence state was achived after 8 h.Shocking was beneficial for adsorption reaction,adsorption quantity tend to be saturated when the shock speed is 180 r min^-1,the adsorption rate was 89%.p H had little effect for adsorption.?2?The best conditions of adsorbed AFB₁ by Auricularia auricula was as follows: initial concentration was 380 ?g·L^-1,temperature was35?,time was 8 h,rotate speed was 200 r·min^-1,the adsorption rate can reach98.3%;?3?Dissolution rate of Auricularia auricula-AFB₁ combination in different solvent was 5.2% 10.4%,which showed that Auricularia auricula and AFB₁ can form a stable combination.3.The rmodynamics and kinetics of Auricularia auricula adsorbed AFB₁ were studied,and its adsorption behavior was analysised.The result showed that Auricularia auricula absorbed AFB₁ accords with the isothermal adsorption equation of Freundlich,and the correlation coefficient R² was 0.9901 0.9981.During the adsorption,? G < 0,? S > 0,? H = 6.31 showed that Auricularia auricula absorbed AFB₁ was uneven polymolecular layer adsorption,and adsorption process was spontaneous exothermic reaction.Adsorption kinetics results showed that Auricularia auricula adsorbed AFB₁ accorded with the false secondary dynamics equation,and the correlation coefficient R² = 0.9976,which showed that the process of Auricularia auricula adsorbed AFB₁ could be divided into fast and slow adsorption.4.The actual effect of Auricularia auricula absorbed AFB₁ was studied through the vitro gastrointestinal and animal experiments and the result showed that Auricularia auricula and AFB₁ can form relatively stable in artificial gastric juice and intestinal juice respectively,and the adsorption rate is 77.6% and77.6% respectively in the reaction 240 min.Animal experimental results show that the feeding AFB₁ can cause significant damage for liver tissue of rats.At the same time,the hepatic function,blood routine and liver lipid peroxidation were abnormal,while the feeding Auricularia auricula could effectively inhibit liver injury and liver function,lipid peroxidation,and routine blood abnormalities caused by AFB₁.