Abstract: The influence of short-wave ultraviolet (UV-C) irradiation at a dose of 3.0 kJ/m2, 10 g/L chitosan coating and their combination on physiological indices of fresh-cut Chinese yam at different storage times was investigated in order to explore the effect of these treatments on preserving the quality of fresh-cut Chinese yam and the underlying mechanism. The results showed that compared with the control group, UV-C irradiation could promote the accumulation of phenolics and flavonoids, enhance antioxidant capacity and reduce oxidative damage. Chitosan coating maintained the quality of fresh-cut Chinese yam for a long time by inhibiting respiration, reducing the permeability of the cell membrane, and decreasing lipid peroxidation in the cell membrane. On day 12 of storage, UV-C irradiation, chitosan coating and their combination reduced the respiration intensity by 15.7%, 21.3% and 23.6%, reduced the total number of bacterial colonies by 24.6%, 18.5% and 30.8%, increased the total phenol content by 13.3%, 16.7% and 22.2%, and enhanced the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity by 17.5%, 9.6% and 20.2% respectively when compared with the control group. Therefore, both treatments especially their combination was effective in preserving the quality of fresh-cut Chinese yam. This study is meaningful for the preservation of fresh-cut fruits and vegetables.

Key words: fresh-cut Chinese yam; chitosan; short-wave ultraviolet (UV-C) irradiation; preservation; storage