Ozonised water treatment delays ripening and senescence of stored papaya fruit via eliciting antioxidant defence system

• Ozonised water (2 mg L –1 ) delays papaya fruit peel browning and senescence effectively • It lowers respiration rate and disease severity while preserving bioactive compounds • Ozonised water treatment lowers oxidative membrane damage by boosting antioxidant enzymes activity Fruit senescence profoundly affects the postharvest quality of papaya, which is linked to oxidative damage from reactive oxygen species and lipid peroxidation during storage. In this study, we analysed the effect and physiological mechanism of ozonised water (2 mg L –1 ) dipping for 5 min on the antioxidant defence system and oxidative membrane damage in extending the shelf life of papaya fruit under cold storage. Ozonised water treatment inhibited respiratory metabolism and ethylene evolution, delayed the ripening and color indices, reduced peel browning and the loss of titratable acidity, and lowered disease severity. Additionally, ozonised water led to substantial elevations in total phenol, flavonoid, radical scavenging activity and antioxidant enzyme activities while mitigating oxidative breakdown by lowering the malondialdehyde and hydrogen peroxide content. Principal component analysis and Pearson correlation (multivariate analysis) further confirmed the effectiveness of ozonised water (2 mg L –1 ) treatment in delaying the senescence of papaya by eliciting antioxidant defence system.