Effect of UV-C treatments on phenolic compounds and antioxidant capacity of minimally processed Satsuma mandarin during refrigerated storage

The effect of UV-C treatments (0.75, 1.5 and 3.0 kJ/m(2)) on fruit quality, phenolic compounds and antioxidant capacity of minimally processed Satsuma mandarin during 12 days of storage at 4 degrees C was studied. The results showed that UV-C treatments had no adverse effects on quality attributes, ascorbic acid, phenolic acids and antioxidant capacity of mandarin segments. Significant increases of flavonoids (22.20% and 21.34% for narirutin, 11.75% and 33.25% for hesperidin) and total phenolics (5.73% and 8.13%) were found in 1.5 and 3.0 kJ/m(2) UV-C treated fruit at 3 days of storage. Further study confirmed that the increase of flavonoids occurred during the first 3 days and diminished after 4 days of storage. UV-C dose at 3.0 kJ/m(2) did not further improve the increase of flavonoids, and 0.75 kJ/m(2) had no significant effects on phenolics. Proper application of UV-C treatment could be a new way to enhance the functional quality of minimally processed citrus fruit. (C) 2012 Elsevier B.V. All rights reserved.