Effect of Heating Pretreatment and Drying Temperature on the Characteristics of Dried Black Soldier Fly ( Hermetia illucens ) Larvae

Black soldier fly larvae (BSFL) offer significant environmental and nutritional benefits, including organic waste reduction and utility as a supplemental feed ingredient. This study investigated the effects of heating pretreatment and drying temperature on the physicochemical characteristics of dried BSFL. A factorial experimental design was employed, combining two pretreatment methods (immersion in hot water [90–95 °C] and steaming) with three drying temperatures (42 °C, 50 °C, 58 °C), yielding six treatment groups with triplicate samples. Analysed parameters included yield, colour, moisture content, ash content, protein content, and lipid content. Drying at 58 °C with hot water immersion pretreatment yielded optimal results: the highest protein content (42.203% ±0.381%), lowest moisture content (2.427% ±0.131%), and favourable lipid (27.18% ±2.71%) and ash (14.833% ±1.81%) levels, alongside a yield of 25.437% ±0.150%. Principal component analysis (PCA) found a sample distribution pattern into 3 clusters with a cumulative variance between PC1 and PC2 of 82.79%. These findings demonstrate that pretreatment and temperature selection critically influence dried BSFL quality, with hot water immersion and higher drying temperatures enhancing nutrient retention and process efficiency.