Antioxidant capacity of fresh-cut vegetables exposed to ionizing radiation

The effect of ionizing radiation on antioxidant capacity, phenolic content and tissue browning of three vegetables was studied. Midrib and non-midrib leaf tissues of Romaine and Iceberg lettuce and endive were irradiated with gamma-rays at 0, 0.5, 1 and 2kGy, and then stored at 7-8 degrees C for 8 days. Antioxidant capacity and phenolic content of tissues as well as tissue browning were analyzed at 1, 4 and 8 days of storage. In general, irradiation increased the phenolic content and antioxidant capacity of both tissue types of all vegetables at day 4 and day 8. The rates of the increase were higher in midrib tissues than in non-midribs, and increased with storage time. Irradiation, however, increased tissue browning of midrib tissues of Romaine and Iceberg lettuce. Our results suggest that irradiation increased nutritional quality of leafy vegetables, but some adverse visual quality changes were encountered. Published in 2005 for SCI by John Wiley & Sons, Ltd.