Nitric oxide maintains postharvest quality of navel orange fruit by reducing postharvest rotting during cold storage and enhancing antioxidant activity

Current study aimed to evaluate the effects of fumigation with 15 mu I L-1 nitric oxide (NO) on the quality of 'Newhall' navel orange fruit during storage at 5 degrees C. Fruits quality parameters, decay rate, antioxidant capacity, antioxidant enzymes activities and disease resistance related enzymes activities were evaluated. NO treatment significantly inhibited the increasing weight loss, maintained soluble solid content (SSC), titratable acid (TA) and vitamin C (VC) contents (P<0.05). Furthermore, NO treatment significantly decreased the respiration rate, suppressed superoxide anion (OA and hydrogen peroxide (H2O2) generation (P<0.05). Antioxidant capacity, superoxide dismutase (SOD), catalase (CAT) and pemxidase (POD) activities in NO-treated navel oranges were significantly higher than controls (P<0.05). Moreover, exogenous NO significantly enhanced the activities of phenylalanine ammonia-lyase (PAL), polyphenoloxidase (PPO), beta-1,3-glucanase (GLU) and chitinase (CHT) (P<0.05). Application of NO would be a promising method in maintaining the quality of postharvest navel orange in the future.

Automated summary

This study investigated the effects of fumigation with 15 mu I L-1 nitric oxide (NO) on the quality of 'Newhall' navel orange fruit stored at 5 degrees Celsius. The results showed that NO treatment could significantly reduce weight loss, maintain important nutrient contents, suppress respiration rate, enhance antioxidant capacity, and increase disease resistance related enzyme activities in the fruit. Application of NO could be a promising method to preserve the quality of postharvest navel oranges in the future.