Carrot browning on simulated market shelf and during cold storage

Browning index, degree of browning, total phenolics content and polyphenoloxidase (PPO) activity of three carrot cultivars-Kendo, Ricardo and Stefano-were studied on a simulated market shelf (20degreesC) and during cold storage (4degreesC). There was a general increase in browning indices and degree of browning during simulated marketing storage for all three cultivars. The three cultivars had similar levels of browning after cold storage but Ricardo reached the highest level after 10 days of simulated shelf life. There appeared to be a rapid increase in total phenolics content during cold storage, which increased further during a simulated marketing trial. The PPO activities of Kendo and Stefano decreased during cold storage whereas that of Ricardo increased, reaching its highest level after 2 months in cold storage. A positive and significant correlation between total phenolics and degree of browning was found for all three cultivars stored for different lengths of time. This research suggests that shorter periods of cold storage reduce the potential for carrot browning and hence prolong the shelf life of carrots. (C) 2004 Society of Chemical Industry.