Abstract
The present paper has dealt with the ascorbic acid content of spinach, as determined by the titration method with 2, 6-dichlorphenolindophenol solutions described by EMMERIE and FUJITA et al. Three varieties used for the experiments were Japanese-variety, Hollan ha and Novel, which were cultivated in the field. Since preliminary test had shown that the petioles and the stems are almost devoid of ascorbic acid, the experiments were made on the contents of leaf-blades.
The freshly cut blades of the Japanese-variety had an ascorbic acid content of 1.9mg per gram before maturity, 2.4mg at nearly full growth and 2.5mg per gram after beginning to bolt. Similar results for the Hollandia and Novel variety were 1.8-1.9, 2.0 and 2.0mg per gram, respectively. These values indicated that the ascorbic acid content of spinach blades is nearly constant during the growth period. Remarkable differences are noticed on the amount of ascorbic acid amang the blades and the roots. The spinach leaf-blade has a larger amount of ascorbic acid than the other portions, during the growing and flowering period.
The blades of three varieties grown on about 33 per cent sun-light averaged 50 per cent lower in ascorbic acid content than those grown on full sunlight and harvested the same day. The variety with the highest value on full sunlight was Japanese-variety (2.4-2.5mg per gram).
