Controlled atmosphere storage of ‘Granny Smith’ apples

Abstract

Abstract The effect of controlled atmosphere (CA) regimens on the storage quality of ‘Granny Smith’ apples has been examined over two seasons. Fruit quality was assessed by physical parameters, incidence of storage disorders and sensory evaluation. There were small differences in fruit quality between 2% O2/2% CO2 and 3% O2/3% CO2 atmospheres, with slight advantages of 2% O2/2% CO2 in terms of titratable acidity. A 2% O25% CO2 atmosphere resulted in fruit of the same firmness as those in 2% O2/2% CO2, although titratable acid levels were lower. Compared with 2% O2/2% CO2, fruit from a 1% O2/ 1.5% CO2 atmosphere were not significantly firmer or more acid. Low (0.75%) CO2 concentrations with either 2% or 3% O2 resulted in softer fruit, suggesting that moderate levels of CO2 are important for maintenance of flesh firmness. Fruit from 2% O2/ 0.75% CO2 atmospheres were also less green than fruit from 2% O2% CO2, but there was no effect of CO2 on colour when O2 levels were 3%. Low CO2 concentrations resulted in...