Effect of drying methods on the nutrient content, protein and lipid quality of edible insects from East Africa

Abstract

This study investigated the effect of different drying methods on nutrient composition and quality of three edible insects from East Africa. Ruspolia differens (grasshopper), Gryllus bimaculatus (cricket) and Bunea alcinoe (caterpillar) were freeze dried, oven dried, sun dried, direct solar cabinet dried, boiled before sun dried or direct solar cabinet dried. Proximate composition, available lysine, and protein digestibility were not significantly affected by drying methods. The protein digestibility corrected amino acid score was lower in boiled dried cricket and caterpillar than the other dried forms. Boiled and dried insects had lowest proportions of linoleate and α-linolenate. Despite these losses in boiled dried insects, the essential amino acid scores and lipid quality indices of differently dried insects were within desirable limits for human nutrition. Sun drying and solar cabinet drying on their own or with prior boiling could be cost-effective and affordable alternatives to freeze drying and oven drying for preserving edible insects.