Blueberry fruit response to postharvest application of ultraviolet radiation

Blueberries (Vaccinium corymbosum, cvs. Collins, Bluecrop) were exposed to ultraviolet light-C (UV-C) radiation treatments from 0 to 4 kJ/m(2) prior to 7 days storage at 5 degrees C plus 2 days at 20 degrees C, 90% RH. Weight loss and firmness were not affected by light treatment. Decay incidence from ripe rot (Colletotrichum acutatum, syn. C. gloeosporioides) on fruit was decreased by 10% with 1-4 kJ/m(2) UV-C light treatments. Antioxidants as measured by total anthocyanin, total phenolics, and ferric reducing antioxidant power (FRAP) were higher in 'Collins' fruit given 0 or 1 kJ/m(2) UV-C compared to unstored fruit. In 'Bluecrop', total anthocyanin content and FRAP values increased with treatment intensity, with highest values seen in fruit given 2 or 4 kJ/m(2) UV-C, but no clear treatment effects were seen in total phenolic content. These results indicate that postharvest application of UV-C radiation can decrease decay caused by ripe rot in blueberries and may enhance antioxidant levels. (c) 2007 Published by Elsevier B.V.