Ultraviolet-C treatment maintains physicochemical quality of water bamboo (Zizania latifolia) shoots during postharvest storage

Abstract

Ultraviolet-C (UV-C) treatment has been used as a method to maintain postharvest quality for many kinds of fruits and vegetables. In this study, we investigated the effects of UV-C treatment on physicochemical changes in water bamboo shoots (WBS) during storage. WBS were treated with UV-C at the doses of 0 (control), 1.06, 2.12, 3.18, 4.24, 5.30, and 6.36 kJ m−2 at 20 °C ± 2 °C for 2 d. The increase in greenness of WBS was inhibited by all UV-C treatments, but the 4.24 kJ m−2 UV-C treatment maintained lightness and whiteness index values of WBS better than other treatments. Thus, the 4.24 kJ m−2 UV-C treatment was selected for use to determine the physicochemical quality of WBS during refrigeration at 10 °C. The UV-C treatment retarded the increases in greenness, chlorophyll a, chlorophyll b, and total chlorophyll content, resulting in maintenance of the whiteness index and colour attributes. It also prevented toughness by retarding lignin increase during storage. Moreover, it induced antioxidant activities and bioactive compounds, especially total phenol, and maintained the activities of antioxidant enzymes such as phenylalanine ammonia lyase and catalase during storage. However, the UV-C treatment did not affect ascorbic acid content and the activities of ascorbic acid peroxidase and guaiacol-peroxidase. These results indicated that UV-C treatment at the dose of 4.24 kJ m-2 is a potential alternative for maintaining physicochemical quality and improving the nutritional quality of WBS during storage.