Studies on the Vitamin C in Vegetables and Fruits (Report 8) : Variation of Vitamin C Content related to the Growth of Light Colored Edible Herbs

Changes of vitamin C content in various parts at different periods of growth were measured in edible herbs, mainly the softwhite vegetables such as the welsh onion (welsh onion family), Chinese cabbage and cabbage (rape family). The following results were obtained. (1) During the growth period, vitamin C content was higher at the initial period. Along with growth especially in the solid head, a marked fall in vitamin C content was noted. In the welsh onion, however, a tendency towards an increase was again noted during the early winter along with the period of increased growth activity. (2) As for the various parts of the vegetable, vitamin C content was highest at the tip of the leaf blade of the welsh onion, while it was highest in the heart leaves of the Chinese cabbage and the cabbage. Namely, vitamin C is found abundantly in those parts with intense physiological activity such as the assimilatory tissues containing large amounts of chlorophyll and the meristematic tissues including the growth spots. (3) In general, vitamin C content is much lower in the white portion than in the green portion. Due to the covering of the roots with soil blocking out the sunshine and whitening due to the solid head, the assimilatory action is decreased in that portion and the property as a kind of storage organ is noted with a marked decline in the vitamin C content. On the other hand, assimilatory action of the outer leaves without the solid head is intensified and the vitamin C quantity is also increased.