Enhancing cold storage quality of Shabrang nectarine using calcium chloride and plasma-activated water

Preserving the postharvest quality and extending the marketability of nectarines is crucial to minimize postharvest losses and maintain consumer acceptance. In the present study, a completely randomized design (CRD) with two factors and five replications was employed to elucidate the effects of calcium chloride (CaCl₂) and plasma-activated water (PAW) on fruit storability and physiological integrity. Six dipping regimes were applied: distilled water for 5 min (control), PAW for 4 min, PAW for 8 min, 2% CaCl₂ for 5 min, 2% CaCl₂ (5 min) followed by PAW (4 min), and 2% CaCl₂ (5 min) followed by PAW (8 min). Fruits were subsequently stored at 0 (harvest), 15, 30, and 45 days, during which progressive declines in postharvest quality were evident, including increased chilling injury, electrolyte leakage, hydrogen peroxide accumulation, and lipid peroxidation, accompanied by a reduction in total soluble solids. Remarkably, the integrated application of CaCl₂ and PAW significantly suppressed these deleterious changes. This combined strategy reinforced the antioxidant defense system by enhancing the activities of catalase, peroxidase, ascorbate peroxidase, and superoxide dismutase, while also improving the radical scavenging capacity, thereby sustaining redox homeostasis. Multivariate analyses (PCA and hierarchical clustering heatmaps) further substantiated that nectarines treated with CaCl₂ + PAW clustered separately from the control and single-agent treatments, indicating a distinctive biochemical and physiological response profile. Moreover, the combined treatment effectively preserved key quality traits such as pH stability and soluble solid retention while concurrently alleviating stress-induced damage. Collectively, these findings demonstrate that the synergistic application of CaCl₂ and PAW constitutes a promising postharvest strategy to maintain fruit structural integrity, delay senescence-related deterioration, and markedly extend nectarine shelf life.