The Effect of Conditions of Storage on the Respiration of Apples

Abstract

SummaryThe respiration of Cox’s Orange Pippin apples has been studied at five temperatures and in seven gas mixtures; comparable samples from some of the temperatures and gas mixtures have been analysed at intervals for concentration of malic acid and carbohydrate. The main conclusions are as follows:The concentration of acid in the fruit decreases logarithmically with time in apples which remain uninjured. When low temperature breakdown supervenes, the rate of loss of acid is accelerated.The rate of loss of acid is reduced by reduction of concentration of oxygen, so long as the respiration remains aerobic. It is also reduced by increase of concentration of carbon dioxide.The loss of carbohydrate varies with rate of respiration, and is reduced by controlled-atmosphere storage conditions. The rate of loss of substrates usually exceeds the loss of carbon as CO2, and the theoretical oxygen-uptake for oxidation of the substrate lost exceeds the observed oxygen-uptake. The lower the temperature, the greater the excess.Carbohydrate substrate is inter-convertible into some non-reducing substance or substances.