Study On The Preparation,Properties And Detoxification Of Aflatoxin B₁ Of Bulbifer Oligo-glucomannan

As a new variety of konjac,the Amorphophallus Bulbifer has the characteristics of large reproduction coefficient,strong resistance and high yield,which shows obvious advantages of planting and cultivation.At present,the research on the Amorphophallus Bulbifer mainly focuses on its biological characteristics,introduction and domestication,tissue culture and breeding and cultivation,etc,few studies on the properties and deep development and utilization of glucomannan,and have no report on the oligosaccharides of the Amorphophallus Bulbifer.The contamination of crop feed by mycotoxins is a global problem,The detoxification methods of toxins include physical,chemical and biological methods.Physical adsorption is the most widely used method.However,it is not clear that many adsorbents are harmful to the body.In this paper,Amorphophallus Bulbifer powder is used as the material,Preparation ofBulbifer oligo-glucomannan?BOGM?with semi-drying enzymatic hydrolysis method.The process of enzymatic hydrolysis was studied and the process conditions for the preparation of BOGM by enzyme method were determined,and the expected oligosaccharides were obtained.The composition of BOGM and its properties was analyzed,provide theoretical basis for its further application.In vitro adsorption test of mycotoxin and animal test,comparison of Amorphophallus Bulbifer powder and Yeast Cell Wall Extract,the adsorption capacity of aflatoxin B₁?AFB₁?was obtained,and a harmless sorbents of mycotoxin were provided.The conclusions of this paper are as follows:1.Study on the preparation process of BOGMThroughsinglefactorexperimentandresponsesurfaceoptimization experiment,the optimum process conditions for BOGM preparation were obtained:The enzyme dosage was 1614 U/g,the hydrolysis time was 3.19 h,the solid-liquid ratio was1:1.73,the enzymolysis temperature was 55?,and the buffer pH was 6,the hydrolysis rate of konjac flour was 50%,and the yield of BOGM was 39.96%.Using the Design Expert 8.05 software and the design principle of Box Behnken,the regression equation ofthehydrolysisrateoftheAmorphophallusBulbiferpowderwas obtained?Y=53.57+3.58A+1.28B+2.62C-0.69AC-1.39A²-0.97C²?.Through single factor experiment,it is concluded that the optimum preparation technology of BOGM is 2000U/g,3 h,solid-liquid ratio 1:1.5,enzymolysis temperature 55,and buffer pH 6.The hydrolysis rate of Amorphophallus Bulbifer powder was 52.62%.Through the analysis response surface and counter,he degree of influence of various factors on the hydrolysis rateofAmorphophallusBulbiferpowderwasobtained:?-mannanenzyme addition>solid-liquid ratio>enzymolysis time.According to the analysis of ANOVA and the analysis response surface and counter,The interaction of the effect of the dosage of?-mannan enzyme and the ratio of solid to liquid on the hydrolysis rate of the Amorphophallus Bulbiferpowder was obvious.The interaction between the amount of enzyme addition and the time of enzymatic hydrolysis,the ratio of solid to liquid and the time of enzymatic hydrolysis was not obvious.The hydrolysis rate of Amorphophallus Bulbifer increased with the increase of the amount of?-mannan enzyme,the enzymolysis time and the ratio of solid to liquid.2.Study on the physicochemical properties and structure of BOGMBOGM soluble in water,insoluble in a solution of more than 60%of the volume of ethanol,The solubility in the 20%,40%volume concentration of ethanol solution is41.33%and 22.63%,respectively.BOGM have better whiteness than Amorphophallus Bulbiferpowder and Yeast Cell Wall Extract,the sample is weakly acidic with a specific gravity of 0.80g/mL and have a strong hygroscopicity.The viscosity of the aqueous solution of the BOGM with different concentrations decreased with the increase of temperature.Under different pH conditions,The degree of Mallad reaction in the BOGM increased with the prolongation of time,The coloration degree of Maillard reaction of BOGM at pH=6.5 is deeper than that of pH=4.5,the coloring degree of different pH conditions was deeper than that of white sugar.In the aging test of inhibiting starch,the inhibition of BOGM to starch aging increased with the increase of adding amount.Analysis of the MALDI-TOF spectrum,from the relative molecules of 381.1 to1515.5 containing 2⁹ sugar,The content of 4,5,6 sugar is higher?4 sugar content?,2,3,7,8,9 sugar content is less?9 sugar content is the least?.Analysis ofInfrared spectra,Compared with the Amorphophallus Bulbifer powder,the basic structure of the BOGM was not changed.Analysis of the corresponding characteristic peaks of oligosaccharides,It is presumed that it is a pyranoid form oligosaccharide.3.Adsorption capacity to AFB₁1)through in vitro adsorption test of aflatoxin B₁,under the conditions of different pH?pH=3.0,pH=6.5?,BOGM,Amorphophallus Bulbifer powder,Yeast Cell Wall Extract?The addition of three kinds of adsorbents were 0.2%?has different adsorption capacity of aflatoxin B₁,the ability to adsorb aflatoxin B₁ at pH=6.5 is larger than that of pH=3.0.Under the same pH condition,the adsorption capacity of different adsorbents on aflatoxin B₁ was in the order of BOGM>Yeast Cell Wall Extract>Amorphophallus Bulbifer powder.At pH=6.5,BOGM has the strongest adsorption capacity of AFB₁,reach 81.50%.2)Animal experiment.The BOGM,Amorphophallus Bulbifer powder,Yeast Cell Wall Extract were was used as toxin adsorbents,the mice were randomly divided into 7groups,Including the blank group?only fed basal diet,K group?,positive control group?basal diet added AFB1,AFB1 group?,experimental group:low,medium and high dose group BOGM?containing 0.1%,0.2%,0.3%BOGM respectively and AFB₁ in basal diet,respectively D₁ group,D₂ group,D₃ group?,Amorphophallus Bulbiferpowder group?adding AFB₁ and 0.2%Amorphophallus Bulbifer powder in basic feed,group A?,Yeast Cell Wall Extract group?AFB1 and 0.2%Yeast Cell Wall Extract in basal diet,J group?.After the end of the feeding,analysis of the organ index?Organ index=organ mass/body mass x 100?,the liver,kidney,spleen and thymus of the AFB₁ group male and female rats were swollen in varying degrees,it shows that the organs of the mice have been damaged,the addition of the toxin adsorbent in the experimental group alleviates the swelling of the organs of the mice and alleviates the damage of the toxin to the organs.In the detection of mouse serum,The content of total protein and albumin in the serum of AFB₁ group was significantly lower than that in the blank group?P<0.05?,Lactate dehydrogenase?LDH?,alanine aminotransferase?ALT?and aspartate aminotransferase?AST?activity was significantly higher than the blank group,superoxide dismutase?SOD?activity than the blank group significantly decreased,malondialdehyde?MDA?content was significantly higher than that in blank group,it shows that the mice have been poisoned by AFB₁.The content of total protein and albumin in the serum of the experimental group was significantly higher than that in the AFB1 group after adding the toxin adsorbent?P<0.05?,the activity of LDH,ALT and AST was significantly lower than that in the AFB₁ group,the activity of SOD was significantly higher than that in the AFB₁ group,and the content of MDA was significantly lower than that in the AFB₁ group,it indicated that adding toxin adsorbent in mouse feed alleviated the negative effect of AFB₁ on serum index of mice and even restored the index to normal level.In the experimental group,with the increase of BOGM content in mice feed,the effect of alleviating the damage of AFB1 to mice was more obvious.The effect of B₂ group is similar to that of J group,indicating that BOGM has better adsorption effect on AFB1.In all the experimental groups,the effect of B₃group was the best,but there was no significant difference between group K and group B₃?P>0.05?.The results show:BOGM can be used as adsorbent for adsorbing AFB1 and have a better adsorpt capacity.