External and Internal Factors Influence Fruit Tolerance to Low-oxygen Atmospheres

Abstract

Fruits of `Bing' cherry (Prunus avium L.), `Red Jim' nectarine (Prunuspersica L.), `Angeleno' plum (Prunus salicina, L.), `Yellow Newtown' and `Granny Smith' apples (Malus domestica Borkh.), and `20th Century' pear (Pyrus serotina L.) were treated with 0.25% or 0.02% O 2 (balance N 2 ) at 0, 5, or 10C to study the effects of these insecticidal low-O 2 atmospheres on their postharvest physiology and quality attributes. Development of alcoholic off-flavor was associated with ethanol accumulation, which was the most common and important detrimental effect that limited fruit tolerance to low O 2 . Relatively higher storage temperature (T), higher respiration rate (R), and greater resistance to gas diffusion (r) enhanced while relatively higher O 2 concentration (C) and higher soluble solids concentration (SSC) reduced off-flavor development. Using a SAS computer program to do multiple regression analysis with T, C, R, r, and SSC as variables, models were developed for prediction of fruit tolerance to insecticidal low-O, atmospheres. Comparison of fruit tolerances and published information on the times required to completely kill specific insects by O 2 levels at or below 1% suggests that low-O 2 atmospheres have a good potential for use as postharvest quarantine treatments for some fruits.