Abstract
The vitamin C (VC) contents and activities of L-galactonolactone dehydrogenase (EC 1.3.2.3, GLDH) and ascorbate oxidase (EC 1.10.3.3, AAO) in the upper and lower parts of the roots of three cultivar varieties of Japanese radish, Ryokki, Kurama and Fukumi, were determined immediately after harvesting and after storage for 7 days. Ryokki contained a higher amount of VC, and had a high level of GLDH activity, and low level of AAO activity. The lower part of the roots of Ryokki retained more VC than the upper part at both 4°C and 15°C, while keeping a high level of GLDH activity but no AAO activity during storage under the same conditions. It is suggested that the GLDH level was positively correlated with the retained VC content, while the AAO level was a negatively correlated with the retained VC content. It seems likely that the best storage temperatures for these three cultivar varieties of Japanese radish are 4°C for the upper parts of the root and 15°C for the lower parts.
