Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2007
Publication Date: 5/1/2008
Citation: Erkan, M., Wang, S.Y., Wang, C.Y. 2007. Effect of UV treatment on antioxidant capacity, antioxidant enzyme activity and decay in strawberry fruit. Postharvest Biology and Technology. 48:163-171. Interpretive Summary: Berry fruits such as strawberries contain high levels of beneficial natural nutrients including vitamins and antioxidants. Antioxidants have been reported to reduce the risk of some types of cancer and other chronic diseases. However, little is known about changes in antioxidant levels in fresh fruits and vegetables after harvest or the effect of postharvest handling on these beneficial nutrients. In our experiments, we found that exposure to ultraviolet light enhanced the antioxidant content in strawberry fruit. We also found that this treatment reduced the amount of mold growth on the fruit during storage. This is important because decay is one of the main factors which terminate shelf-life of berry fruits. We have shown that exposure of strawberry fruit to ultraviolet light could both improve the nutritional value and lengthen shelf-life. This information is useful for plant scientists involved in berry research and could be beneficial to the berry industry and consumers.
Technical Abstract: The changes in antioxidant capacity, enzyme activity and decay inhibition in strawberry fruit (Fragaria x ananassa) illuminated with different UV-C dosages were investigated. Three UV-C illumination durations and dosages, 1 min, 5 min and 10 min, (0.43, 2.15 and 4.30 kJ m-2) tested promoted the antioxidant capacity and enzyme activities and significantly reduced the severity of decay during storage at 10°C compared to the control. UV-C illumination for 5 and 10 min showed the best results for enhancing antioxidant capacity, enzyme activity and inhibiting decay. All UV-C dosages increased the phenolic content of strawberry fruits as well. Strawberry fruits illuminated with UV-C for 5 min showed higher total phenolic capacity than other tested UV-C dosages. However, control fruit had the highest anthocyanin content after 15 days storage at 10°C. UV-C illumination for 5 min had the highest antioxidant capacity expressed as oxygen radical absorbance capacity (ORAC) values after storage for 15 days. All UV-C dosages inhibited the development of decay comparing to control treatment, but 5 and 10 min UV-C illumination gave the best decay control.