Physiological and Quality Responses of `Bartlett' Pears to Reduced O2 and Enhanced CO2 Levels and Storage Temperature

Abstract

`Bartlett' pears (Pyrus communis L.) tolerated up to 10 days of exposure to atmospheres containing 1.0%, 0.5%, or 0.25% O2 at 0, 5, or 10C without any detrimental effects on their quality attributes. The fruits also tolerated 4 to 6 days of exposure to air enriched with 20%, 50%, or 80% CO2 at the three temperatures. The beneficial effects of exposures to the O2-reduced or CO2-enriched atmospheres included reduction of respiration and ethylene production rates and retardation of skin yellowing and flesh softening. While 1.0% or 0.5% O2 and 20% CO2 did not increase ethanol and acetaldehyde contents, 0.25% O2 slightly increased and 50% or 80% CO2 dramatically increased the contents of these two volatiles in juice of the fruits. The effects of low O2 or high CO2 on the above attributes generally became more pronounced at the higher temperatures. The low O2 or high CO2 treatments did not significantly affect either soluble solids content or titratable acidity. Low O2 did not influence, but high CO2 slightly increased pH of the fruits.