Novel grasshopper protein/soy protein isolate/pullulan ternary blend with hesperidin derivative for antimicrobial edible film

Abstract

As a green agricultural resource and a new alternative protein, edible insects have the potential to become an excellent source of biopolymer. In this study, a new ternary blend composites were formed based on the mixture of edible grasshopper protein and soybean protein isolates by adding pullulan (PUL). The combined effect of incorporation of antimicrobial agent methyl hesperidin (2.5 %, 5 %, 7.5 % and 10 %) was investigated. The addition of PUL can greatly improve the tensile strength of protein blend composites but has no positive impact on elongation at break. 5 % methyl hesperidin can further increase tensile strength to 7.36 MPa with no deterioration on elongation at break. The SEM and XRD results showed good compatibility between PUL and protein blend. The WVP and WCA results showed that the hydrophobicity of composites increased slightly. Moreover, thermal analysis presented that the thermal stabilities of composites were impaired. The increasing of methyl hesperidin content enhanced antibacterial activity against E. coli and S. aureus of ternary blend film, proving its application value as active packaging.

Keywords

• Edible insects
• Locust (Locusta migratoria)
• Grasshopper
• Insect protein
• Active packaging
• Methyl Hesperidin