An active cling film developed from pomelo peel for synergistic preservation of Oncorhynchus mykiss: Utilizing K/Fe enzyme-like materials and natural extracts

The high protein content of Oncorhynchus mykiss , despite its nutritional value, poses a risk of microbial contamination and foodborne illnesses in fresh products, thus necessitating paramount importance for effective preservation. In this study, a synergistic preservation system possessing both antimicrobial and antioxidant functions was developed from pomelo peel. Enzyme-like material with peroxidase-like activity (K/Fe-PP) were synthesized from pomelo peel, KCl and FeCl 3 via a hydrothermal method. These enzyme-like materials catalyze the continuous generation of hydroxyl radicals (▪OH) from H 2 O 2 , enabling sustained bacterial inhibition. An ethanol extract of pomelo peel, harnessing the strong reducing power of its enriched phenolic compounds, was used to inhibit lipid oxidation in fish. To realize their synergy, the K/Fe-PP and the pomelo peel extract were added into a chitosan matrix, which served as a carrier, and were subsequently fabricated into a composite cling film (CS/K/Fe-PP).CS/K/Fe-PP films were applied to Oncorhynchus mykiss under refrigerated storage. The spoilage of Oncorhynchus mykiss was assessed by the value of malondialdehyde (MDA), acid value, total volatile basic nitrogen (TVB-N), histamine content, and total viable count (TVC). It was shown that the optimal cling film extended the storage time of Oncorhynchus mykiss by 3–6 days. This work not only provides a new strategy for applying catalysis based on enzyme-like materials in aquatic product preservation but also establishes a sustainable approach for the high-value utilization of waste biomass resources.