The combination treatment of MeJA and pectin coating regulates ROS homeostasis in collision bruising tissues for pear...

Postharvest collision bruising during handling often leads to significant quality deterioration in perishable fruits. This study developed an optimized pectin/diatomite (PT/DT) composite film and investigated the synergistic effect of methyl jasmonate (MeJA) and PT/DT coating on regulating ROS homeostasis in bruised pears. The PT/DT composite film demonstrated superior mechanical strength (tensile strength of 41.01 MPa) and improved barrier properties (21.3 % reduction in water vapor permeability), attributable to the uniform DT dispersion within PT matrix. The synergistic application of MeJA and PT/DT coating effectively mitigated oxidative stress for bruised pears, as evidenced by 32.7 % decrease in malondialdehyde content and 22.2 % reduction in H₂O₂ accumulation at their peaks compared with control. This was achieved by enhancing the antioxidant enzyme activities, with SOD, CAT, APX, and GR at levels 15.8 % to 115.1 % higher than the control on day 30. Meanwhile, the combination treatment also sustained non-enzymatic antioxidant capacity via ascorbate-glutathione cycle, maintaining higher levels of AsA (75.71 mg/kg FW) and GSH (13.28 mg/kg FW). This dual intervention significantly maintained fruit quality and accelerated wound healing in bruised pears, offering a promising approach for postharvest quality preservation using biodegradable coatings combined with phytohormone treatment.