Storage and handling effects on a CO2-related internal browning disorder of 'Braeburn' apples

'Braeburn' apple (Malus xdomestica Borkh.) fruit can be susceptible to the development of an internal disorder called "'Braeburn' browning disorder" (BBD), Factors associated with development of this disorder were investigated. Susceptibility to injury was greater in fruit exposed to 2 or 5 kPa CO2 than to 0 kPa CO2 during storage. Susceptibility also increased with decreasing O-2 partial pressure in the range of 5 to 1 kPa in the storage atmosphere. However, fruit stored in 1 kPa O-2 remained firmer than those stored at higher partial pressures, regardless of CO2 level. BED appeared to develop during the first 2 weeks of storage, and delays in air at 0 degrees C prior to controlled-atmosphere (CA) storage decreased incidence and severity of the disorder. The incidence of BED was also reduced when the time to establish CA conditions was prolonged. We recommend that 'Braeburn' apples be stored under CA conditions of less than or equal to 1.0 kPa CO2 and 3.0 kPa O-2. Delayed application of CA for 2 weeks after fruit enter the coldstorage may also reduce development of BED.