Effect of Processing Methods on Nutrient Composition of Black Soldier Fly Larvae Reared on Slaughterhouse Waste and Rice Bran

Abstract

Black Soldier Fly (BSF) larvae have emerged as a sustainable and nutrient-dense resource for livestock feed, primarily due to their high protein and lipid contents. However, the nutritional composition of BSF larvae is substantially influenced by the processing methods. This study aimed to evaluate the effect of five processing methods (room dried, sun dried, oven dried, microwave dried, and roasted) on the nutrient content of BSF larvae reared on slaughterhouse waste and rice bran composite substrate. The treatments in this study were different processing methods namely room dried: conducted at ambient temperatures of 25–26°C for 31 days, sun dried: performed daily under sunlight exposure from 07:00 to 17:00 for 24 days, oven dried: executed at a controlled temperature of 60°C for 36 hours, microwave dried: completed in 20 minutes using a microwave, and roasted: conducted on a stainless-steel pan over a moderate flame for a duration of 4 minutes. Results showed that the processing methods significantly affect (P < 0.05) dry matter, ash, crude protein, crude fiber, and ether extract contents across the treatments. Room dried and sun dried were better suited for preserving ether extract. On the other hand, heat-based methods such as oven dried, microwave dried, and roasted were effective in enhancing protein content while reducing lipid levels. These findings highlight the critical role of processing methods in determining the nutritional profile of BSF larvae.