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 be 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 with low density polyethylene film significantly reduced weight loss and chilling injury during low temperature storage. Lower O-2 and higher CO2 levels were found in internal and in-package atmospheres of heated fruit than controls. Ethylene was not detected in the in-package atmosphere of treated fruit, 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 significant increase in putrescine was noted in packaged fruit treated at 53 degrees C for 4 min after 14 days of storage. Spermine levels decreased in control fruit during storage. However, heat treatment in combination with film packaging maintained higher levels of spermine in peppers during storage than controls. These results indicated that hot water treatment in conjunction 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.