Abstract
Using the spinach (Japanese variety) as samples, the ascorbic acid contents of the blades, the activation of the enzyme which oxidizes ascorbic acid into dehydroascorbic acid, and the effect of carbon dioxide on the ascorbic acid content of plants were studied from the satndpoint of storage. The amount of ascorbic acid in the blades was determined by the titration method with 2, 6-dichlorphenol-indophenol solutions, described by EMMERIE and FUJITA et al.
The fresh blades, which were just being cut, contained the ascorbicacid in the state of reduced form and the same amount of theascorbic acid was found even in the extracted plant juice. The ascorbic acid oxidase might be absent in the juice, because no reaction of enzyme appeared on synthetic ascorbic acid after adding the juice to it.
The ascorbic acid content of blade tissue was influenced remarkably by the carbon dioxide contained in air in the storage, and the highest content was found in the sample which had been kept in the lowest concentration of carbon dioxide.
The disappearance of reduced ascorbic acid in the storage started rappidly in the contact with carbon dioxide regardless of temperature. After loss of ascorbic acid during storage in the air, which contained much carbon dioxide, there was no complete recovery even if the extract of tissue was treated with hydrogen sulphide for 30minutes
