Extending Storage Life and Ensuring Arrival Quality of ‘Bartlett' Pears after Long-distance Export by Maintaining Cold Chain and MA Chain

There is a potential of using modified atmosphere packaging (MAP) to replace CA for long-term storage and to ensure arrival quality of pears after long-distance export. However, there are insufficient data on optimum MAP conditions for pears. The objective of this research was to investigate the effects of MAP on extending storage life and maintaining fruit quality of ‘Bartlett’ pears at simulated transit conditions. ‘Bartlett’ pears harvested at commercial maturity were packed (20 kg/box) in four different MAP bags varying in gas permeability and stored in air at –1.1 °C for 5 months. Control fruit packed in standard perforated polyethylene liners lost fruit firmness (FF) and skin color at 3 months. MAP1&2 achieved steady-state atmospheres of 5% to 12% O₂ + 4% to 6% CO₂, inhibited ethylene production and ascorbic acid degradation, and extended ‘Bartlett’ pear storage life for 4 months with high quality and up to 5 months with certain skin green color loss. The headspace atmosphere of MAP3 equilibrated at ~2% O₂ + ~6% CO₂, which resulted in fruit internal browning (IB) after 3 months of storage. MAP4 with higher gas permeability (~18% O₂ + 1% to 2% CO₂) had minimal effect on delaying fruit softening and yellowing in cold storage compared to control. After 3 months at –1.1 °C plus 3 weeks at simulated transit conditions, MAP1&2 fruit maintained FF and skin color at transit temperature of 2.0 °C, maintained skin color but reduced FF to about 66.7N (the critical FF to resist scuffing) at 4.5 °C, and developed IB at 7.5 and 10 °C (6% to 8% CO₂ + < 2% O₂). The MAP 1&2 fruit could ripen to high eating quality after the simulated transit at 2.0 and 4.5 °C. In conclusion, MAP could increase the storage life of ‘Bartlett’ pears with high eating quality by up to 2 months and ensure arrival quality after long-distance export by maintaining cold chain and MA chain.