Bioconverter insects: A good example of circular economy, the study case of hermetia illucens

The production cycle based on extraction, transformation, production, consumption and waste has not been sustainable for years. The goal is to have production cycles capable of self-regeneration, and therefore to identify a new way of managing byproducts is needed, one that would turn them into a resource. In the production cycle of the food industry, losses and waste account for about 1,3 billion of tons a year, and thus around 1/3 of world production for human consumption. Insects can represent a valid solution to the reuse and valorization of food industry by-products. In environmental and economic fields, an innovative application is offered by the capacity of some insects to bioconvert waste material into valuable products. Bioconverter insects can valorize organic waste from the agrifood industry through bioconversion. This process allows to obtain numerous products of high biological and economic value: proteins and lipids of animal origin, chitin and residues from the bioconversion process (frass of insect and partially digested organic material, rich in in uric acid and chitin, comparable to soil conditioner for agriculture and therefore usable for crop fertilization). Proteins and lipids deriving from some insect species could be used for feed production, and lipids can be exploited for the production of biodiesel or could find application in cosmetics field. Moreover, insect's chitin and its derivative chitosan can find many possible applications in agricultural, biomedical, pharmaceutical and industrial fields as well as in wastewater treatment. The breeding of insects for animal feed and as an alternative source of energy could represent one of the solutions to be adopted in the future. To date, in Europe the larval biomass obtained from bioconversion process can be marketed for the feeding of game animals, reptiles, fur animals and other insectivorous species (EU Reg. 68/2013, EU Reg. 142/2011); they can also be transformed into processed animal proteins (PAP) and then in flours with high nutritional content, to replace or supplement the protein and lipid quotas present in conventional feeds. The specific conditions of processing, production, storage, transport and use of insect flour for aquaculture (fish farming) has been governed by the European Regulation 2017/893 that allows the use of proteins for fish feed derived only from seven species, including the dipteran Hermetia illlucens. In the present paper, we describe the sustainable use of H. illucens to bioconvert agrifood by-products and produce proteins, lipids, chitin and its derivatives; furthermore, we shall outline their applications in the view of a zero-waste circular economy.