Effects of Storage Temperature, Storage Atmosphere, and Growing Region on Internal Browning Disorder of `McIntosh' Apples

Abstract

Our study found that storage temperature, storage atmosphere and growing region interactively affect the probability of internal browning disorder in `McIntosh' apples (Malus domestica Borkh.). Higher incidence of internal browning occurred in apples stored for 6 months at 1 °C (34 °F) in controlled atmosphere (CA) with 2.5% O2 + 1.5% CO2 or in CA with 1.0% O2 + 0.5% CO2 than apples stored at 1 °C in air or stored at 3 °C (37 °F) in air or CA conditions. The magnitude of the incidence of internal browning varied among apples harvested from different growing regions. Apples from London, Ontario, Canada were less tolerant to these two storage conditions and therefore greater number of fruit developed internal browning than apples from other regions. In addition, apples from the London growing region and stored at 1 °C in CA with 1.0% O2 + 0.5% CO2 had greater probability of internal browning than apples stored at 1 °C in CA with 2.5% O2 + 1.5% CO2. However, there was no difference between these two CA storage conditions in causing internal browning among apples harvested from other three growing regions. Few apples showed internal browning when they were stored at 3 °C, no matter of what storage atmosphere was used. Therefore, internal browning disorder can be avoided or significantly reduced by storing apples at 3 instead of 1 °C, in these two CA conditions. Internal browning disorder will not be a risk if apples are stored in air at 1 or 3 °C.