Polyamines induced by hot water treatments reduce chilling injury and decay in pepper fruit

Treatment of peppers with hot water (53 degrees C) for 4 min was found to b e effective in alleviating chilling injury and reducing decay after 14 and 28 days of storage at 8 degrees C. Treatment at 45 degrees C for 15 min was less effective in maintaining pepper quality during storage. Packaging wit h low density polyethylene film significantly reduced weight loss and chill ing injury during low temperature storage. Lower O-2 and higher CO2 levels were found in internal and in-package atmospheres of heated fruit than cont rols. Ethylene was not detected in the in-package atmosphere of treated fru it, but was present in the control. Polyamine levels increased immediately after hot water treatments. Putrescine levels increased during storage at 8 degrees C particularly in heat-treated fruit and in packaged fruit. A sign ificant increase in putrescine was noted in packaged fruit treated at 53 de grees C for 4 min after 14 days of storage. Spermine levels decreased in co ntrol fruit during storage. However, heat treatment in combination with fil m packaging maintained higher levels of spermine in peppers during storage than controls. These results indicated that hot water treatment in conjunct ion with film packaging may delay chilling injury and decay of bell peppers through a mechanism that involved elevation of polyamine levels. (C) 2000 Elsevier Science B.V. All rights reserved.