COLD-STORAGE INFLUENCES INTERNAL CHARACTERISTICS OF NECTARINES DURING RIPENING

'Flavortop' nectarines [Prunus persica (L.) Batsch] were stored at -0.5C or 3C for 0, 1, 2, 3, or 4 weeks, after which the fruit was ripened at 15C. After ripening, fruit samples were tested daily or every second day for extractable juice, internal conductivity, and woolliness. The change in the percentage of extractable juice during ripening differed very little among the five storage periods. A rapid increase in internal conductivity occurred during ripening in fruit with or without cold storage, but the onset of the increase was advanced with longer cold-storage periods. No woolliness developed in fruit not placed in cold storage or in fruit cold-stored for 1 or 2 weeks at -0.5C or 3C. Woolliness only developed during ripening of fruit cold-stored for 3 or 4 weeks at -0.5C or 3C. Incidence of woolliness increased to high levels during ripening and decreased thereafter to no woolly fruit by the 11th day. The lowest values for extractable juice coincided with the highest incidence of woolly fruit. Fruit stored for 4 weeks took longer to pass the woolliness stage. At the end of the ripening period, cold-stored fruit were similar in appearance and juiciness to those ripened without cold storage. Nectarines stored at 3C generally developed woolliness earlier, had a lower incidence of woolliness, and took longer to overcome the problem than fruit stored at -0.5C. Incidence of browning of the mesocarp tissue was greater at 3C than at -0.5C.