From farm to table: Enhancing lychee preservation with spatial electric field in smart cold chain systems

A spatial electric field (SEF) refrigeration system combined with a starch-based composite film was developed to enhance postharvest preservation of lychee. During storage, appearance, texture, nutritional composition, and antioxidant capacity were evaluated. The SEF and film co-treatment (STF) effectively delayed pericarp browning, reduced weight loss (4.31 %), maintained moisture (77.9 %), and preserved textural. It also retained high levels of soluble solids, sugars, organic acids, vitamin C (31.62 mg/100 g), and phenolics (68.69 mg/g), while suppressing polyphenol oxidase and peroxidase activities and maintaining low CMP (39.97 %). These effects were attributed to SEF-induced stabilization of CMP and antioxidant defenses, coupled with the gas barrier and moisture control properties of the starch-based composite film. Metabolomic analysis confirmed the regulation of antioxidant and energy metabolism pathways, enriching metabolites like γ-linolenic acid, indoleacetic acid, and 1-phenylethylamine enriched. This study provides a novel, green strategy for lychee preservation, supporting the development of intelligent cold chain systems.