Preparation and characterization of polypeptide film/coating derived from Idesia polycarpa Maxim. Cake meal and its application in nectarine preservation

• Preparation of novel fruit cling film/coating from a novel antioxidant peptide CIP. • The films have excellent oxidation resistance, mechanical properties and thermal stability. • The coating/3% fraction is effective in maintaining the quality of nectarines and slowing down aging. Considering that the peptide from Idesia polycarpa Maxim.cake meal polypeptide (CIP) is a novel antioxidant agent, this study aimed to develop an efficient and safe food film by incorporating the CIP agent into a gelatin matrix. The films with different concentrations of CIP were characterised and applied in the preservation of nectarines. The results indicated that the CIPF/3% fraction exhibited significant moisture barrier properties, with a water vapor permeability (WVP) of only 8.12 % ± 0.09 %. Additionally, it demonstrated excellent mechanical and antioxidant properties, with scavenging capacities of 76.31 % ± 0.597 %, 65.98 % ± 0.444 %, and 60.98 % ± 0.231% for DPPH, ABTS, and hydroxyl radicals, respectively, surpassing those of other fractions. In nectarine freshness preservation, the Coating/3% fraction showed the best performance. It significantly reduced the weight loss rate of nectarines, improved fruit firmness, maintained the pH value, and minimized nutrient losses, including ascorbic acid and Total soluble sugars (TSS). Furthermore, it effectively preserved the bright surface color of nectarines and extended their shelf life. In summary, the specific environmental protection, safety, and preservation qualities of the CIPF/Coating in food packaging suggest a promising potential for its application.