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 degreesC in 20 kPa CO2 (high pCO(2)) or long-term storage at 0.5 degreesC in 0.5 kPa O-2 + 0.05 kPa CO2 (low pCO(2)) or 1.5 kPa O-2 + 3 kPa CO2 (medium pCO(2)). CO2-injury (brown-heart) occurred in apples exposed to high pCO(2) or medium pCO(2), but no internal disorders were observed in fruit held at 20 degreesC in air or 4 months at 0.5 degreesC in low pCO(2), regardless of watercore severity at harvest. Depending on harvest date anti 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 pCO(2). Accumulation of ethanol and acetaldehyde occurred in watercored 'Fuji' apples even under ambient (21 kPa O-2,) conditions and this accumulation increased with watercore severity regardless of storage environment. (C) 2002 Elsevier Science B.V. All rights reserved.