Comparison of the in vitro protein digestibility of Protaetia brevitarsis larvae and beef loin before and after defatting

•In vitro protein digestibility of Protaetia brevitarsis larvae was evaluated.•Larvae and beef proteins had different molecular distribution.•Digesta of larvae had significantly more proteins under 3 and 10 kDa than beef.•Defatting with hexane improved digestive accessibility to actin in larvae.•P. brevitarsis larvae with great digestibility can be a substitute for beef protein. Protein digestibility of Protaetia brevitarsis larvae before and after defatting by hexane was compared with that of beef loin in an in vitro digestion model. Larvae had higher crude protein content and 10% trichloroacetic acid (10% TCA)-soluble α-amino groups than beef. Decreases in the levels of total free sulfhydryl groups and 10% TCA-soluble α-amino groups were detected in larvae and beef after defatting (P