PHYSIOLOGICAL-CHANGES IN PEACHES RELATED TO CHILLING INJURY AND RIPENING

Firm-breaker (FB) and firm-mature (FM) peaches cv. 'Paraguayo' were ei ther stood for 4 weeks at 2 degrees C or subjected to three cycles of 1 day of intermittent warming (IW) at 20 degrees C every 6 days at 2 d egrees C. Normal postharvest ripening and post-storage ripening at 20 degrees C were also studied in order to relate postharvest physiology with the onset of chilling injuries (CI) (woolliness, gel breakdown an d scald). As far as we know, both gel breakdown and scald have been de scribed and reported on peaches for the first time. FB peaches were mo re sensitive to CI than FM ones. A high respiration rate and ethylene production in conventionally stored fruit after 2 weeks of storage, fo llowed by a drop in ethylene production, was accompanied by the develo pment of CI in fruit of both maturity stages. IW strongly reduced CI d uring storage. Periodic warming acclimatised chilled fruit to subseque nt periods of chilling by allowing them to ripen due to the production of a suitable amount of ethylene, depending on their maturity stage a t harvest. The increase in ethylene production during post-storage rip ening could be related to the development of over-ripeness. (C) 1998 E lsevier Science B.V. All rights reserved.