Optimizing Waste Management: The Impact of Pre-treatment on Black Soldier Fly Larvae for Sustainable Protein Sourcing

Amidst escalating global urbanization and population growth, the necessity to revolutionize food systems and redefine waste management strategies has become paramount. This study aimed to contribute to the evolution of protein resource diversification within animal feed and offer a sustainable solution for organic waste management using black soldier fly larvae (BSFL) in Bafia, Cameroon. A survey characterized waste production in both restaurants and households to assess their quantity and quality. Subsequently, collected organic wastes were subjected to two pre-treatments: heating (60°C) and fermentation (4 days), while another batch was used fresh as feeding substrates for BSFL in comparison to a broiler starter diet in a 17 days larval feeding experimental period. Throughout the study period, various parameters were evaluated, including physicochemical properties of substrates, bioconversion and growth parameters, life cycle traits of adult BSF, and the nutritional composition of the larvae. The survey revealed a significant disparity in food waste disposal practices: while 98% of restaurants disposed of waste indiscriminately, 95% of households reported using food waste as fertilizer.In the experimental phase, heat treatment exhibited the highest substrate temperature and pH levels throughout the experimental period. Larvae reared on heated substrates showed superior daily weight gain (0.05g/larva/day) and bioconversion rate (41.76%) compared to other substrates. Additionally, larvae from heat-treated substrates had highest lipid (35%) and protein (29.89%) contents compared to all other organic waste treatments, although his protein content remained lower than that of the chick’s starter diet, which had a higher value (37.53%). Notably, flies from larvae reared on heated substrates emerged two days earlier than those from other treatments. These early-emerging adults lived longer and produced more eggs than their counterparts. This study has revealed a stark contrast in the disposal practices of food waste between restaurants and households in Bafia. The findings underscore the potential of utilizing waste, especially after heat pre-treatment, to produce high-quality black soldier fly larvae, offering a promising avenue for sustainable protein sourcing in animal feed while addressing organic waste management challenges.