2018 Volume 71 Issue 5 Pages 251-256
Recently, the Consumer Affairs Agency revised the food labeling system used in Japan. The new system allows fresh agricultural products to be labeled as “Foods with nutrient function claims”. The satsuma mandarin (Citrus unshiu Marcow.) is one of the most commonly consumed domestic fruits in Japan, and is rich in vitamin C. Therefore, there has been high expectation that the satsuma mandarin can be labeled as a food with nutrient function claims. However, there are very few data concerning the differences in ascorbic acid content among cultivars and their associations with fruit quality. In this study, we measured the ascorbic acid content of various satsuma mandarin cultivars in relation to their sugar content. We found that the cultivar with the highest total ascorbic acid content was wase (an early-ripening variety) , followed by gokuwase (an extremely early ripening variety) . On the other hand, okute (a late ripening variety) and a storage cultivar (3 months of storage) had significantly lower total ascorbic acid contents than wase and/or gokuwase, and the oxidized ascorbic acid content was higher in okute and the storage cultivar than in the wase cultivar. The satsuma mandarin cultivar with the lowest oxidized ascorbic acid content was one grown in greenhouses. Our study revealed that ascorbic acid content is significantly and positively associated with sugar content.
