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´Mibaek´ peaches were stored at 0℃ for 4 weeks, and then were examined during ripening at 20℃. Woolliness developed only in cold-stored fruits. After cold storage, severity of the disorder increased progressively until the 5th day of ripening and thereafter tended to decrease. In non-stored fruit, water-soluble pectin (WSP) content increased, EDTA-soluble pectin (ESP) content remained constant, and sodium carbonate-soluble pectin (SSP) content decreased during ripening. In cold-stored fruits, WSP content was lower, and SSP content was higher than that of non-stored fruits during the ripening period. ESP content of cold-stored fruits increased during ripening and, after the 5th day of ripening, which was higher than that of non-stored fruits. Cold-stored fruits showed lower polygalacturonase (PG) activity, which is likely to be a cause of lower WSP content and higher SSP content. Pectinmethylesterase (PME) activity was not affected by cold storage. These results suggest that the poor texture described as ´woolliness´ was caused by altered pectic polymer breakdown by inhibited PG activity. PME activity was not correlated with the woolliness.
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