Tenebrio Molitor Larva Comprehensively Treats Food Waste And Degradable Plastic Method Research

Food waste is perishable,resulting the leachate and odor which are easy to spread viruses and pathogenic bacteria causing harm to human health and the environment.With the improvement of people living standards and the rapid development of the catering industry,the output of food waste has also increased year by year.The harmless treatment and resource utilization of food waste has become the focus of public attention.Plastic is a synthetic polymer extracted from petroleum,which is difficult to degrade.Exploring more scientific and effective measures to deal with plastic waste has become a major problem in the domestic and international environmental ecology.Yellow mealworm is known as "the treasure house of protein feed".It is an important protein resource insect.It can not only be widely used as feed for livestock and poultry or special economic animals,but also for health food.Due to the omnivorous characteristic of Tenebrio molitor L.,it can treat organic waste and convert it into nutritional components such as protein and fat of the worm.This method has good economic and ecological benefits.At present,existing researches mainly focus on the processing technology and comprehensive utilization technology of food waste.It is rarely used for classification research and yellow mealworm feed,and no attention has been paid to the enrichment,toxic effects and long-term exposure of health risks in the breeding process.In addition,the study also found that although the mealworm larvae can degrade plastic,but their degradation rate is low.In this study,food waste was used as the research object in Chengdu.Based on the optimization of the method for the treatment of food waste by Tenebrio molitor L.,the quality and safety of the product were evaluated.And this research established a method system for the integrated treatment of kitchen waste and plastic by Tenebrio molitor L.The main results are as follows:(1)Comprehensively analyze the three factors: the biomass increase rate,feed utilization rate,and feed conversion rate of the meal wastes,food peels of the Tenebrio molitor L.,and the optimal method of transforming food waste by mealworms larvae was that disposable food waste accounts for 50%,and peel accounts for 50%.Under this method,the biomass increase rate of Tenebrio molitor L.reached 618%,the feed utilization rate was27.5%,and the feed conversion rate reached 28.7%.(2)The crude protein content of Tenebrio molitor L.cultured according to the optimal breeding method was 46.2%,which was slightly lower than that of fish meal protein;the crude fat content was 21.6%.At the same time,essential amino acids accounted for 44.6% of the total amino acids,and the ratio of essential amino acids to non-essential amino acids was80.5%,which is in line with the WTO/FAO ideal protein reference model.Tenebrio molitor L.can enrich to varying degrees Cu,Zn,As,Ni,Cr,Cd and Pb in food waste and wheat bran.The concentrations of As,Cr,Cd and Pb meets China’s food safety standards(GB 2762-2017),and the results of human health risk assessment show that heavy metalsd and PAHs have no non-carcinogenic and carcinogenic risks.In addition,the pH value of the faeces produced in this process complies with the organic fertilizer standard of the Ministry of Agriculture(pH:5.50-8.50),and the total nutrients(total nitrogen+total phosphorus+total potassium)content of the worm-faeces was 2.70%,which was lower than organic fertilizer standard NY 525-2012 in China’s agricultural industry.The potential ecological hazards of insect dung are minor hazards;PAHs risk assessment is safe.(3)Using Tenebrio molitor L.comprehensively treat food waste and plastic,the biomass increase rate of Tenebrio molitor in polystyrene(PS)and polyethylene(PE)groups increased 6.82 and 9.33 times,respectively,and the degradation rate of plastics increased 3.19 and 3.60 times,respectively,reaching 40.8% and 55.2%.Although the crude protein is lower than the fish meal protein standard,it meets the chicken breeding standard(NY/T33-2004).What’s more,the addition of food waste increased the intestinal microbial species of Tenebrio molitor by 30 and 23 speciesed,of which the Staphylococcus abundance of Tenebrio molitor was increased by 5.60% and 4.40%,and the abundance of Lactococcus was increased 1.00%、1.00%,thus promoting the growth and development of Tenebrio molitor.The output of Tenebrio molitor meets China’s chicken breeding standards,and insect dung meets China’s Ministry of Agriculture organic fertilizer standards.