Closing the loop with pretreatment and black soldier fly technology for recycling lignocellulose-rich organic by-products: A progressive review

Abstract

The rise of the global population and improving living standards have increased food demand, imposing significant pressure on agricultural systems. As a result, substantial quantities of organic by-products rich in lignocellulose, termed organic agricultural biomass (OAB), are produced. These materials, rich in cellulose, hemicellulose, and lignin, provide environmental and economic difficulties if not treated properly. Conventional animal feed cannot adequately digest OAB owing to its structural complexity, restricting its effectiveness. Pretreatment strategies have become vital for altering the lignocellulosic structure of OAB, improving enzymatic hydrolysis, and transforming complicated polysaccharides into fermentable sugars. These techniques-physical, chemical, physico-chemical, and biological enhance fibre degradation, promote nutrient extraction, and adhere to circular economy principles. Recently, black soldier fly larvae (BSFL, Hermetia illucens L.) have shown potential as a recycling agent, particularly within EU regulatory frameworks, for converting agri-food by-products into nutrient-rich feed for livestock. This research examines the integration of pretreatment techniques with BSFL technology to recycle lignocellulose-rich by-products, highlighting the creativity in merging these methods to enhance nutrient conversion. The results indicate a sustainable approach to waste valorisation, mitigating the environmental effects of lignocellulosic by-product management while providing economic advantages. This interdisciplinary approach shows potential for sustainable agriculture and bio-economies, enhancing resource recovery via nature-based, circular solutions. Future research should concentrate on pretreatment methods for various biomass compositions and developing BSFL-rearing substrates as a viable recycling agent.

Keywords

• Co-digestion
• Pretreatments
• Bioconversion with insects
• Sustainable insect-based feeds and foods