Data-driven preservation of value-added rapeseed shoots during cold storage: Cultivar-specific effects of chitosan, electron-beam irradiation, and melatonin

Rapeseed shoots are nutrient-rich but highly perishable vegetables whose postharvest quality is strongly influenced by cultivar and storage duration. This study compared chitosan coating (CH), electron-beam irradiation (EBI), and melatonin treatment (MT) in three double-low Brassica napus cultivars during 28 d of storage at 4 °C. Changes in physical quality, nutritional attributes, oxidative status, antioxidant enzyme activities, and lignification-related characteristics were evaluated and integrated using machine learning, a baseline-corrected postharvest deterioration index (ΔPDI), partial-correlation analysis, and three-way ANOVA. All three treatments reduced water loss, maintained firmness, chlorophyll, ascorbic acid, soluble protein, and soluble solids, and alleviated membrane lipid peroxidation and PAL-associated lignification to varying degrees. Significant cultivar × treatment interactions confirmed that treatment responses were cultivar dependent. Under the specific conditions tested, CH and MT showed broadly comparable overall quality-retention performance and generally resulted in lower cumulative deterioration than EBI, although RH928 responded particularly well to CH and S28 to MT. The LASSO-L1 storage-stage classifier achieved an accuracy of 0.885 and identified weight loss, firmness, peroxidase activity, respiration rate, soluble solids, and PAL activity as major indicators associated with storage progression. Treatment classification was more moderate (Ridge-L2 accuracy = 0.655), indicating substantial overlap among treatment-response patterns. Molecular docking and 100-ns molecular dynamics simulations suggested a possible interaction of melatonin near the PAL substrate-recognition region, but did not establish direct binding or enzyme inhibition. Overall, the results provide a multivariate basis for cultivar-adapted preservation of rapeseed shoots during refrigerated storage.