The Study Of The Enrichment Of Heavy Metals And Quality Evaluation Of Pleurotus Ostreatus In Culture Medium

Edible fungus is a kind of fungus that people widely choose to eat or use for medicine.China is a big producer of edible fungus,but the level of cultivation and production is often uneven,and the management of quality supervision is relatively weak.At present,we pay more attention to the pesticide residues in the cultivation and production,but ignore the more serious problems in the practical production of edible fungus Metal residue problem.The residues of heavy metal ions will not only have a great impact on the growth and nutritional value of edible fungi,but also cause great harm to human health once they are eaten.In view of the quality and safety problems in the production and cultivation of edible fungi in China,this topic will carry out specific research and analysis in the following aspects: firstly,the content of heavy metal ions in the raw materials selected in the production process of edible fungi in China is determined,and the determination results are used as indicators to provide high-quality raw materials for the production line of edible fungi in China In addition,the adverse effects of metal ions in edible fungi will be further analyzed.In this paper,we take Pleurotus ostreatus as an example,choose to artificially add heavy metals in simple Pleurotus ostreatus culture medium,and carry out relevant determination after a period of time,so as to carry out the research on the absorption and degradation of heavy metals in Pleurotus ostreatus and the influence of heavy metals on the nutritional components of Pleurotus ostreatus.Finally,according to the analysis of the relevant experimental results,the problems that need to be paid attention to in the production process of metal ions are obtained,which provides the corresponding scientific basis for the production safety of edible fungi in China,and helps to formulate and revise more scientific safety standards for the production of edible fungi in China,so as to ensure the production of more healthy and safe edible fungi products for the people of the whole country in the future.The main research contents and results are as follows:1.In this project,90 samples of edible fungi(including Flammulina velutipes,Auricularia auricula,Agaricus bisporus,Dictyophora,Pleurotus ostreatus,Auricularia auricula,Pleurotus ostreatus,etc.)were selected to determine the heavy metals in them respectively.The measurement standard refers to the national standard GB 2762-2017 national food safety standard The limit of pollutants in food,according to the measurement results,it is found that the cadmium content of two edible fungi has exceeded the national standard,which are:bamboo fungus(content is 1.5 mg/kg),mushroom(content is 2.1 mg/kg);in addition,the lead content in one part of mushroom reaches 1.2 mg/kg,which also greatly exceeds the national standard.In these samples,the mercury content is less than 0.2 mg/kg,the arsenic content is less than 1mg/kg,both of which meet the requirements of national standards.2.180 samples(including wood chips,bran,cottonseed hulls,etc.)were taken from the raw and auxiliary materials of edible fungi,and four heavy metals such as mercury,lead,cadmium,and arsenic were determined.The content of cadmium and mercury is not much.There are 35 parts with lead content within the range of 1.0mg/kg-6.0mg/kg,accounting for19.4%,and the content of arsenic within the range of 1.0mg/kg-8.0mg/kg There are 11 shares accounting for 6.1%.Therefore,the control of raw and auxiliary materials is particularly critical.3.On the basis of the above experimental results,the absorption and enrichment of heavy metals in Pleurotus ostreatus were further studied and analyzed(1)With the increase in the amount of input As,Pb,Cd,and Hg,the pollution parameters of Pleurotus ostreatus continued to increase.,The pollution situation is rising rapidly.(2)The heavy metals rich in the cultivation medium can be absorbed by the oyster mushroom,and the enrichment effect of different heavy metals is also different,from large to The small order is: Hg,Cd,As,Pb.In terms of the enrichment effect of the above several heavy metals,the absorption and enrichment law of Pleurotus ostreatus complies with the power and polynomial curve equations,and the coefficients reach 0.996,0.8032,0.9803 and 0.838,all of which satisfy Obvious or extremely obvious level.(3)With the increase of as,Hg,Pb and CD,the effect of controlling the yield of Pleurotus ostreatus is stronger,and the degree of reducing the yield of different heavy metals is different.(4)Lead,cadmium,mercury and arsenic have adverse effects on the nutritional components of Pleurotus ostreatus.The results showed that the increase of as content had no effect on the protein formation process of Pleurotus ostreatus,but with the increase of as and Pb content,the ash content of Pleurotus ostreatus decreased significantly,and the addition of heavy metals was negatively correlated with the fat content of Pleurotus ostreatus.Adding heavy metals such as CD and Hg would reduce the amino acid score and amino acid chemical score of Pleurotus ostreatus,Adding heavy metals will also affect the total amount of amino acids.Increasing the amount of heavy metals As and Cd will increase the total amount of amino acids by 9.17% and 5.93%,while increasing the amount of heavy metals Pb and Hg will reduce the total amount of amino acids by 4.32% and 12.0 %.