Effects of Blanching Methods on Nutritional Properties and Physicochemical Characteristics of Hot-air Dried Edible Insect Larvae

Global meat consumption is increasing worldwide, however, supply remains lacking. Several alternative protein sources, such as cultured meat, plant-based protein production, and edible insects, have been proposed to overcome this shortage. Interestingly, edible insects are characterized by superior digestive and absorptive qualities that make them the ideal replacement for traditional protein production. This study aims to further the processing ability of insect protein by investigating the effects of various blanching methods, such as blanching (HB), roasting (HR), and superheated steam (HS), on the nutritional properties and physicochemical characteristics of proteins extracted from Hermetia illucens larvae. The drying rate, pH value, colour analysis, amino and fatty acid profile, as well as bulk density, shear force, and rehydration ratios of the above pretreatment methods, were explored. HS was found to have the highest drying rate and pH value analysis showed that HB and HS samples have significantly higher values compared to the other modalities. Raw edible insects had the highest value in the sum of EAA and essential amino acid index (EAAI) when compared to essential amino acids. HB and HS showed significantly lower bulk density results, and HS showed the highest shear force and the highest value in rehydration ratio, regardless of immersion time. Thus, combining the above results, blanching and superheated steam blanching pretreatments were found to be the most effective modalities in improving the processing aptitude of Hermetia illucens after hot-air drying.