Biochemical and sensory characteristics of the cricket and mealworm fractions from supercritical carbon dioxide extraction and air classification

Insects represent a sustainable but under-exploited food resource partly due to the chitin-containing exoskeleton and also the high lipid content that hamper the production of food ingredients. Here we present dry fractionation technology for upgrading house crickets (Acheta domesticus) and yellow mealworm larvae (Tenebrio molitor) by extraction with supercritical carbon dioxide followed by separation to fine and coarse fractions by air classification. The defatted insects contained 73-79% crude protein that was partially fractionated by air classification to protein-enriched fractions containing less chitin. In addition to the significant difference in the coarse mouthfeel between the fine and coarse fractions, the fine fraction of crickets was perceived saltier and more intense in flavour, and the fine fraction of mealworms having more meat-like flavour than the coarse fraction. Thus, it seems that the fractionation process has a clear impact on the texture (coarseness), but the flavour characteristics could be varied according to the insect variety. Overall, the dry fractionation technology holds promising prospects for the production of insect-based food ingredients that are modified in their chitin content and flavour intensity, does not contain identifiable anatomical parts, and thus, could better meet consumer acceptance.