Characterisation of ‘Royal Gala’ and ‘Cox's Orange Pippin’ apple (Malus domestica) softening during controlled atmosphere storage

Abstract

Firmness is an important trait of postharvest quality in apple fruit (Malus domestica). This study characterises softening rates of early season cultivars before, during, and after controlled atmosphere (CA) storage. ‘Royal Gala’ and ‘Cox's Orange Pippin’ apples in CA had a triphasic softening curve during storage similar to that of fruit in regular air storage (RA). Fruit in CA had a longer initial slow softening phase, and a slower rapid softening phase, than fruit in RA. Firmness benefits in the market arising from CA were attained only when CA was applied to fruit before the onset of rapid softening. Fruit in CA also exceeded an internal ethylene concentration (IEC) of 1.5 μl litre^‐1 later, and had a lower maximum IEC, than fruit in air. Thus, CA may extend the initial slow softening phase, and reduce softening in the rapid softening phase by decreasing ethylene production in both cultivars.

Key words:

• Malus domestica
• firmness
• softening rate
• ethylene
• controlled atmospheres
• temperature
• empirical modelling
• quality