Submitted to: Postharvest Biology and Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/29/2006
Publication Date: 12/20/2006
Citation: Smith, D.L., Stommel, J.R., Fung, R.W., Wang, C.Y., Whitaker, B.D. 2006. Influence of cultivar and harvest method on postharvest storage quality of pepper (capsicum annuum l.) fruit. Postharvest Biology and Technology. 42:243-247. Interpretive Summary: The most significant postharvest problem in bell peppers is water (weight) loss and shriveling. The cause of water loss is not known, although it is believed the peel thickness/composition may be one of the determining factors. To address this problem, we chose to examine different harvesting and storage methods. Our results over two growing seasons clearly demonstrated that the harvesting methods (tearing versus cutting) had no significant impact on fruit water loss during storage. Storage temperatures also had no significant impact on water loss, however temperatures below 10°C resulted in severe chilling damage. Fruit wax samples were also examined and no correlation was found between wax content and water loss. The only significant difference found in water loss was among pepper variety. One type lost water very rapidly and also suffered the greatest chilling injury while another cultivar lost weight slowly and was significantly resistant to chilling injury. In summary, there are differences in storability of pepper varieties and screening for water loss and chilling injury are helpful for selection of peppers most suitable for cold-storage. This research will help seed companies to identify superior varieties and can be used by breeders to improve quality of bell peppers for the fresh-cut and fresh pick markets.
Technical Abstract: The principal physiological factors that negatively impact pepper fruit during shipment and storage and subsequent marketability include water loss and chilling injury. The current study evaluates the effect of harvest methodology on postharvest water loss from sweet bell pepper fruit and the potential relationship between water loss and chilling injury in cold-stored fruit. The influence of cultivar, epicuticular wax, and AOX gene expression on water loss and chilling injury were examined. Our results demonstrated that the degree of water loss in pepper fruit is subject to genotype effects and pre- and postharvest environments as evidenced by year to year variation in fruit storage attributes. A comparison of pepper fruit harvest methods, wherein peduncles were either torn or cut, demonstrated little difference in harvest method for percent water loss. Observations on fruit water loss in relationship to fruit size suggested that fruit cuticles are the primary barrier to water loss. A clear relationship between epicuticular wax content and fruit water loss was not evident in our studies. Cultivars varied in their susceptibility to chilling injury and fruit water loss was positively correlated with the degree of chilling injury. No correlation was found between endogenous AOX transcript levels and cultivar-specific susceptibility to chilling injury. The results illustrate the difficulty of identifying indices correlated with water loss for development or identification of cultivars with improved storability. We did find that there are significant differences in storage attributes of pepper cultivars and routine screening for water loss and chilling injury are advantageous for selection of cultivars most suitable for cold-storage.