Effect of nano-ZnO-packaging on chilling tolerance and pectin metabolism of peaches during cold storage

- Nano-ZnO-based LDPE (NZLDPE)-packaging was applied to the cold storage of peaches.
- The chilling tolerance of peaches was improved by NZLDPE-packaging.
- NZLDPE-packaging was benefit to rapid formation of low O2 and high CO2 environment.
- The activities of pectin-related enzymes were coordinated by NZLDPE-packaging.
- NZLDPE-packaging was contributed to pectin metabolism to alleviate chilling injury.

The effects of nano-ZnO-based low-density polyethylene (NZLDPE)-packaging on chilling tolerance and pectin metabolism in postharvest “Hujingmilu” peaches were investigated. Peaches packed in low-density polyethylene (LDPE) and NZLDPE were stored at 2 °C for 40 d. Compared with the control, both packages alleviated the development of chilling injury, showed higher fruit firmness with lower browning index, electrolyte leakage, relative viscosity, and decay rate. NZLDPE-packaging performed better than LDPE-packaging because of the rapid formation of low O2 and high CO2. Moreover, NZLDPE-packaging inhibited pectin esterase and enhanced polygalacturonase and β-galactosidase, leading to the promotion of alkali soluble-pectin and water-soluble pectin, and the decrease of chelater-soluble pectin. These effects were of great benefit to the maintaining of cell wall structure and the degradation of calcium-pectate gel, which finally alleviated the chilling injury and therefore maintained good quality during chilling stress.

145