Storage Humidity Influences Fruit Quality and Permeability to Ethane in `McIntosh' Apples Stored in Diverse Controlled Atmospheres

Abstract

Storage of `McIntosh' apples (Malus domestica Borkh.) in high humidity (94% to 100% RH) or in 0.5% CO2 plus 1.0% O2 at 3C (LO) atmospheres decreased resistance to ethane diffusion relative to fruit stored in low humidity (75% RH) or in 5.0% CO2 plus 3.0% O2 at 3C (SCA), respectively. Loss of fruit firmness of SCA- or LO-stored `McIntosh' apples, determined immediately after storage or after 7 days at 20C, decreased with increased storage humidity in each of three crop years. Storage humidity did not significantly affect (P = 0.05) fruit titratable acids or soluble solids contents. High storage humidity (96% to 100% RH) generally increased the incidence of senescent disorders (consisting of senescent breakdown and senile brown core) in SCA-stored fruit, while humidities of 92% to 100% RH decreased the incidence of low-O2 injuries (epidermal bluing and cortical browning) in LO-stored fruit. Senescent disorders were found in SCA-stored fruit, but not in LO-stored fruit. The incidence of decay was not significantly affected by either storage humidity or atmosphere.