Using insects to convert plants, animal feed and manure into marketable products Can we make the production of useful proteins, lipids and comparable resources from underused organic side-streams or residue profitable by exploiting insects? An EU initiative explored innovative processes and approaches to introduce new products and compounds. Industrial Technologies © pitaksin, Shutterstock The EU-funded InDIRECT project developed indirect cascading biorefinery methods to convert a variety of side-streams from various sectors into useful and commercial products. Side-streams include organic and plant biomass from the agricultural, processing and retail sectors. Examples are grass, green leaves, fruit, vegetables and presscakes. “We targeted the biorefinery of underspent side-streams to be used as feed ingredients for insect rearing and investigated whether insect-based products have potential as marketable compounds,” says coordinator Leen Bastiaens. InDIRECT received funding from the Bio-based Industries Joint Undertaking, a public-private partnership between the EU and industry. New value chain for converting biomass into valuable products The researchers applied a three-step biorefinery model to convert the different side-stream feedstocks into a homogeneous biomass. They used the black soldier fly and the lesser mealworm for this conversion. The research team subsequently utilised the insects’ own biomass. The activities required the production of over 1 t of insects. The resulting insect biomass was processed into crude extracts, which were then purified and converted into new products and compounds. These include proteins and oligopeptides, lipids, chitin, chitosan and derivatives, N-light compost and minor compounds. “These products will have significantly higher values than current biomass applications,” notes Bastiaens. “Presently, agro-industrial and food side-streams are often used as feed or bioenergy sources.” Valuable compounds can be recycled from this biomass via different biorefinery approaches. Project partners compared direct and indirect approaches. “A direct approach is challenging to scale for small biomass side-streams because biomass is only seasonally available and can’t be produced all year,” explains Bastiaens. “On the other hand, it’s an approach that can generate a large variety of potentially high-value compounds when applied in a cascading mode – proteins, carbohydrates, fibres, and multiple minor compounds like carotenoids and polyphenols.” Transforming waste-fed insects to proteins using biorefinery Indirect biorefinery converts side-streams into crude extracts via a two-step process: conversion of biomass by insects, and subsequent biorefinery of the insect biomass. “The indirect approach shows potential for year-round, relatively stable production of mainly chitin, proteins, lipids and N-light compost,” adds Bastiaens. “The crude fractions such as proteins, lipids, chitosan, carbohydrates and minor compounds obtained through both approaches need to be further purified and processed towards viable products in sectors like feed, chemistry and food.” Optimising biorefinery processes will increase conversion efficiency (product/tonne biomass input) compared to the existing state of play and maximise feedstock values (euro/tonne biomass input). A position paper presents the overall findings, their potential and challenges. The project’s findings are also accompanied by 19 recommendations for stakeholders along the entire insect value chain. In addition, a report summarises the legal framework and bottlenecks involving the use of insect-derived products. “InDIRECT has greatly boosted the visibility of insect-based value chains, and helped lower their barriers to implementation in Europe,” concludes Bastiaens. “This new value chain isn’t economically feasible yet because of legal and technical constraints. However, potential solutions were identified, including targeting high-value applications like chemicals, textiles and cosmetics, and valorising all generated biomass like frass and sheddings.” Keywords InDIRECT, biomass, insect, side-stream, compound, biorefinery, feed, value chain
