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% O 2 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% CO 2 at the three temperatures. The beneficial effects of exposures to the O 2 -reduced or CO 2 -enriched atmospheres included reduction of respiration and ethylene production rates and retardation of skin yellowing and flesh softening. While 1.0% or 0.5% O 2 and 20% CO 2 did not increase ethanol and acetaldehyde contents, 0.25% O 2 slightly increased and 50% or 80% CO 2 dramatically increased the contents of these two volatiles in juice of the fruits. The effects of low O 2 or high CO 2 on the above attributes generally became more pronounced at the higher temperatures. The low O 2 or high CO 2 treatments did not significantly affect either soluble solids content or titratable acidity. Low O 2 did not influence, but high CO 2 slightly increased pH of the fruits.