Effects of pre-storage heat treatment on fruit ripening and decay development in different apple cultivars.

摘要

Apple fruits of different cultivars were heat-treated at 38 degrees C for 4 d immediately after harvest, then stored at 0 degrees C for 6 weeks ('Gala') or 4 months ('Golden Delicious' and 'Red Fuji'). Upon removal from storage, fruits were kept for 7 d at 20 degrees C as a shelf-life test. During storage and shelf-life, various ripeness parameters were measured. 'Golden Delicious' and 'Red Fuji' apples were artificially inoculated with Penicillium expansum or Botrytis cinerea before heat treatment, then stored at 20 degrees C for 3 weeks, or 0 degrees C for 6 weeks, and the development of fruit decay was recorded. The respiration rate decreased and the ratio of soluble solids contents (SSC): titratable acidity (TA) increased for all heat-treated fruits. For 'Gala' and 'Golden Delicious' apples, heat treatment significantly reduced ethylene evolution, reduced softening during cold storage, and reduced membrane electrolyte leakage after cold storage and shelf-life. Better quality was maintained at the end of the shelf-life for these two cultivars. However, the effects of heat treatment on ethylene production, membrane electrolyte leakage and texture parameters of 'Red Fuji' apples were not significant. The rotting caused by P. expansum or B. cinerea was very severe, especially for apples stored at 20 degrees C. However, decay was completely inhibited in 'Golden Delicious' and 'Red Fuji' apples that had been heat-treated after inoculation. It was concluded that the response to heat treatment varied according to cultivar. Pre-storage heat treatment could delay the ripening of 'Gala' and 'Golden Delicious' apples and maintain storage quality. Although heat treatment gave no beneficial effects on the quality of 'Red Fuji' apples, it could be applied to control disease in this apple cultivar..