Of key importance in the search of alternative sources of proteins seem to be new systems of agricultural production, orientated towards mass production of protein with the use of such organisms as insects, which are able to use nutrients from agricultural by-products. Bioconversion of agricultural waste with the use of insects may supplement the future demand for protein, but such residues are still an untapped food resource. Due to the lack of technical and legal support, the current mass insect production systems are poorly developed, hence insect protein is marketed mainly as an ingredient in animal feeds. Among the insect products with an especially high potential to be used for nutritional purposes in terms of the economic efficiency of producing high value food and feed products, it is worth mentioning the black solder fly larvae (Hermetia illucens).
The edible insect industry is strategic to ensure a constant supply of feed components for aquaculture. However, due to the fact that insects are a protein component in fish nutrition, fluctuations in demand and supply, correlated with this industry, may be susceptible and thus may directly affect the price of this substrate. Insect protein reached its record price level, i.e. USD 2,300, in 2015. These fluctuations relate to components from H. illucens. It is also important that the insect production market is constantly growing, and economists forecast an increase to about 1.200 million tons in 2025. Despite this, in aquaculture it is necessary to ensure constant access to this feed component, shorten supply chains and use by-products, which would result in meeting the goals of sustainable development.
The purpose of these R&D studies is to present the possibility of using small-scale H. illucens cultures for use in fish farms. The research assumes the implementation of sustainable up-cycling of agricultural residues: modular cascading waste conversion system into H. illucens larvae as a feed component. It is predicted that the main use of this type of insect raw materials in food systems will be the reduction of amounts and the recycling of waste biomass from food production and consumption, followed by its auxiliary application, as a protein source for animals. The technological system for the production of H. illucens dry larvae was divided into 4 stages. Stage 1 was the setting up of the larval culture in boxes/trays and the preparation of the substrate, Stage 2 was larvae feeding, Stage 3 was the collection and hygienisation of the larvae and Stage 4 was the drying up and storing the product in the freezer. The planned concept of the technological process was designed to make use of various side streams from the agricultural and food industry. The presented assumptions may be important for the eco-friendliness of fish farming and may be economically justified due to the additional stream of feed components available directly in the aquaculture farm.
Acknowledgement. Project financially supported by a research project entitled “Sustainable up-cycling of agricultural residues: modular cascading waste conversion system”; research grant agreement No. FACCE SURPLUS/III/UpWaste/02/2020, research is supported by the National (Polish) Centre for Research and Development (NCBiR) (Project FACCE SURPLUS/III/UpWaste/02/2020).