The influence of pre-storage delayed cooling on quality and disorder incidence in ‘Honeycrisp’ apple fruit

Abstract

Abstract The influence of a pre-storage, 7-day, 20 °C warming period on post-harvest apple ( Malus xdomestica Borkh.) fruit quality and disorder expression—soft scald and low temperature breakdown in particular, were investigated in ‘Honeycrisp’ fruit grown in the Annapolis Valley of Nova Scotia. The apples from 7-year old trees were harvested from three commercial sites on Sept 30, 2002 (early) and Oct 10, 2002 (late), after which, half of the fruit was immediately cooled to 5 °C (control), while the other half was held for 7 days at 20 °C (delayed cooling treatment). Both the control and delay cooled apples were then stored at either 3 or 5 °C in controlled atmosphere (CA) (2.5 kPa O 2 ; 1–1.5 kPa CO 2 ) or refrigerated air (RA) storage for 4 and 6 months. Fruit quality measurements and disorder incidence were recorded following storage removal and a 7-day shelf-life at 20 °C. Delayed cooling had no effect on fruit firmness, soluble solids (%), titratable acidity, epidermal greasiness, senescent breakdown, and bitter pit (the incidence of these latter disorders was low), while moisture loss from the delay cooled fruit ranged from 1.2 to 1.3% following the 7-day treatment. Delayed cooling strongly suppressed the development of the storage disorders soft scald and low temperature breakdown, which in the control fruit reached upwards to 30% of the sample. No CA- or RA-related differences in these disorders were observed in the fruit receiving the pre-storage delayed cooling treatment. Storage rot was not influenced by delayed cooling and was present in upwards to 32% of the fruit from the late-harvested apples after 6 months of storage. In regions where soft scald and low temperature breakdown are serious postharvest problems, it appears that a delayed cooling period prior to storage will help minimize economic loss.