Patterns of flesh reddening, translucency, ethylene production and storability of ‘Friar’ plum fruit harvested at three maturity stages as affected by the storage temperature

• Different patterns of flesh reddening and translucency were found in ‘Friar’ plums.
• Anthocyanin accumulation contributed to flesh reddening under chilling temperature.
• Pectin solubilization contributed to flesh translucency under chilling temperature.
• Concomitant patterns of ethylene production accounted for disorders of the plums.

Flesh reddening and translucency are two predominant physiological disorders of ‘Friar’ plum (Prunus salicina Lindl.) during cold storage. In order to investigate the occurrence of these disorders, the fruit were harvested at early-, mid- and late-maturity stages and stored at 0, 2, 5, 15 or 25 °C, 85–95% relative humidity. Three concomitant patterns for flesh reddening, translucency and abnormal softening (melting) of ‘Friar’ plums were evident: rapid increases in these disorders at 5 and 15 °C, a delayed/suppressed of these disorders at 0 and 2 °C, and normal ripening at 25 °C, irrespective of fruit maturity stage. Three similar temperature-mediated patterns of anthocyanin accumulation related to flesh reddening, pectin solubilization related to translucency, and decline in firmness related to abnormal softening were observed. Three patterns of ethylene production were also identified: early and dramatically high ethylene production at 5 and 15 °C, suppressed ethylene production at 0 and 2 °C, and almost no ethylene production at 25 °C. These results suggest that ethylene may be involved in the onset and development of flesh disorders of ‘Friar’ plums during cold storage. Respiration greatly increased, water-soluble pectin content increased early during storage and remained high, and insoluble pectin (i.e., protopectin) decreased, in plums held at 5 and 15 °C. Overall, the biochemical and physiological behavior of plums were greatly affected by storage at 5 and 15 °C compared with 0, 2 and 25 °C, and late-maturity plums were more susceptible to storage disorders.

Development of physiological disorders of ‘Friar’ plums during storage at different temperatures.Figure optionsDownload as PowerPoint slide