Apple ( Malus domestica ) softening in the postharvest coolchain: Effects of delayed cooling and shelf‐life temperatures

Abstract ‘Royal Gala’ and ‘Cox's Orange Pippin’ apples ( Malus domestica ) soften rapidly after harvest, resulting in poor fruit quality after extended periods of storage and transportation. This study sought to characterise the effects of delayed cooling, intermittent warming, and exposure to shelf‐life temperatures on softening of these cultivars during postharvest handling. Rapid cooling of freshly harvested fruit to cold‐storage temperatures delayed the onset of rapid softening and improved the firmness market life of both cultivars. Fruit transferred temporarily from 0.5–3°C to ambient temperatures (10–20°C) were softer once returned to 0.5–3°C, an effect exacerbated by increased temperature and duration of the break in the coolchain. Storage temperature and duration did not affect subsequent softening rates of either cultivar at 20°C. Softening rates, derived from constant temperature treatments, were able to describe softening in fruit treated with stepwise changes in temperature, indicating that rate of softening at a given temperature was not affected by prior exposure to temperatures between 0.5 and 20°C. Results from this research could be used to develop models that estimate softening of both cultivars during postharvest handling.