Impact of watercore on gas permeance and incidence of internal disorders in ‘Fuji’ apples

The impacts of watercore on incidence of internal disorders and other physiological characteristics of ‘Fuji’ apples (Malus domestica Borkh) were determined following short-term exposure at 20 °C in 20 kPa CO2 (high pCO2) or long-term storage at 0.5 °C in 0.5 kPa O2+0.05 kPa CO2 (low pCO2) or 1.5 kPa O2+3 kPa CO2 (medium pCO2). CO2-injury (brown-heart) occurred in apples exposed to high pCO2 or medium pCO2, but no internal disorders were observed in fruit held at 20 °C in air or 4 months at 0.5 °C in low pCO2, regardless of watercore severity at harvest. Depending on harvest date and orchard, the severity of CO2-injury was significantly correlated with watercore severity. Watercored tissue has a lower intercellular air space volume, reduced permeance to gas diffusion and increased internal pCO2. Accumulation of ethanol and acetaldehyde occurred in watercored ‘Fuji’ apples even under ambient (21 kPa O2) conditions and this accumulation increased with watercore severity regardless of storage environment. © 2002 Elsevier Science B.V. All rights reserved.