Microwave-assisted Lewis acid catalysis for one-step preparation of high-performance buckwheat peptide-based films: Efficacy, mechanism, and applications

This study presents a novel method for the efficient preparation of peptide-based films through microwave-assisted Lewis acid catalysis (MALC) of buckwheat globulin (BG). The MALC process efficiently degraded BG into small molecular peptides (1.6–1.8 kDa) within 10 min. These peptides formed aggregates with a high β-sheet content through coordination with metal ions, which demonstrated a strong ability to create highly cross-linked network structures. The peptide-based films (PFs), without the addition of any cross-linking agents, exhibited excellent tensile strength (1.65–3.62 MPa), elongation at break (11.52–44.61 %), superior oxygen barrier properties (0.06–2.45 cm³/m²·day), and low swelling rates (20–36 %). Notably, the PFs also possessed strong antibacterial, antioxidant, and ultraviolet resistance capabilities, extending the shelf life of fresh chili peppers by approximately 7 days. This study enhances our understanding of the interactions between transition metal ions and plant proteins, establishing a technological foundation for the large-scale application of plant protein films.