Effects of controlled atmosphere storage on respiratory metabolism of apple fruit tissue

Abstract

AbstractThe effects of CO2 and O2 concentrations commonly used in fruit storage upon various respiratory processes in apple fruit tissue have been investigated. In manometric experiments 10% CO2 inhibited CO2 release from succinate supplied to peel discs by over 50%; CO2 release from malate was inhibited at high substrate concentrations, while CO2 release from pyruvate was not affected. High CO2 concentrations also inhibited 14CO2 release from succinate 1,4‐14C and succinate 2,3‐14C supplied to peel discs. It is concluded that succinate dehydrogenase is the respiratory enzyme most affected by CO2 concentration.Oxygen uptake was found to be 50% inhibited at ambient concentrations of 0.5% O2 for cortical tissue and 5% O2 for peel tissue. It is concluded that cytochrome oxidase is responsible for O2 uptake in peel and cortical tissue. The apparent low affinity for O2 in peel respiration may be due to limited O2 diffusion through the tissue. It is concluded that O2 uptake by the bulk of the apple is not directly affected by O2 concentrations employed in fruit storage.