The effect of harvest date on the responses of Discovery apples to modified atmosphere retail packaging

Abstract

SummaryIn order to study effects of physiological maturity on responses of Discovery apples to modified atmosphere (MA) retail packaging, samples of fruit were picked at 3–4 day intervals over a 3‐week period spanning the development of the climacteric rise in respiration and the normal marketing season for the variety. The apples were packed in MA (301∼.ethylene vinyl acetate) or perforated control packs and held under simulated marketing conditions at 10 or 20°C. The degree of modification of the pack atmospheres and the effects of MA packaging on fruit ripening changes were influenced by harvest date and related to the respiration rate of fruit when packed. MA packs were effective in retarding softening and skin colour changes in immediately pre‐climacteric and early climacteric fruit. There was little risk of taint development, except during 14‐day simulated marketing periods at 20°C. Little beneficial effect of MA packaging was found in apples harvested 4 days before the onset of the climacteric; relatively little deterioration occurred in such fruit in perforated control packs. Beneficial effects of MA packaging on ripening changes and quality attributes were reduced, and taint risk enhanced, when the technique was used for late picked fruit with much higher rates of respiration. Possible causes for the observed relationship between the different stages of physiological maturity of Discovery apples and their responses to MA packaging are discussed.