Preliminary Evaluation of Aqueous Protein Extraction from Black Soldier Fly Larvae (Hermetia illucens L.)

This study aimed to explore the efficacy of mild water-soluble protein extraction procedures on black soldier fly larvae (BSFL), a potential alternative and sustainable protein source for food. Different conditions were tested for extraction of water-soluble proteins including phosphate buffered saline (PBS) and Tris-HCl buffer in a pH range from 7.0 to 9.0. The total protein content and the water-soluble protein content were measured by Lowry BioRad DC™ protein assay. The molecular weight distribution of water-soluble proteins was characterized using SDS-PAGE. The black soldier fly larvae contained 42.3% protein on a dry matter basis, which is comparable to other studies. After extraction, the water-soluble protein fraction ranged from 5.5 to 17.2%, dependent on the buffer conditions, and total protein content and discoloration of the supernatant was observed, which could be an indication of oxidation. Moreover, the SDS-PAGE method allowed the determination of molecular weight distribution of the protein fraction showing no protein degradation with discrete bands and the most intensive band <75 kDa was observed. The extraction of water-soluble BSFL proteins was mild, easy, fast and in agreement with other studies. Further research should focus on the characterization and techno-functional properties of the aqueous protein extracts as food ingredient alternative.