Polyamine Accumulation Following Hot‐Water Dips Influences Chilling Injury and Decay in‘Friar’ Plum Fruit

Mature‐green ( Prunus salicina Lindl. cv.‘Friar’) plums were treated in water at 40°C for 40 min, 45°C for 35 min, 50°C for 30 min or 55°C for 25 min, stored at 0°C for 35 d plus 9 d of ripening at 20 to 25°C. During cold storage, putrescine and cadaverine accumulated most compared to spermine and spermidine, especially in fruits treated at 45 or 50°C, compared to other treatments. Chilling injury (CI) and decay symptoms were severe in fruits of control, 55 and 40°C‐treated fruits. Decay incidence was also high in fruits stored at room temperature. Chilling injury and decay symptoms were retarded in fruits treated at 45 and 50°C, which also maintained increased polyamines and low ethylene. By the end of their shelf life, only 45 and 50°C‐HWD treated fruits were fit for market.