Note on Tea as a Source of Vitamin C.

Abstract

With the exception of cabbage and lettuce the leaves of plants have not been examined quantitatively for their content of vitamin C. The observations of Miura 1 indicated that different kinds of tea possessed widely different amounts of vitamin C, and the quantity found in green tea compared favorably with the content of the usual anti-scorbutic foodstuffs. Fermentation and its accompanying oxidative changes are a part of the commercial processes of tea manufacture and it seemed desirable to confirm Miura's observations with the possibility of correlating the data with the accepted facts relative to the oxidative destruction of vitamin C.

A series of 300 gm. guinea pigs on Sherman's 2 basal ration (with equal weights of rolled oats and wheat bran) was used for curative tests. These animals gained their last 50 gm. of body weight on the basal ration plus a leaf of cabbage. After the latter was omitted scurvy developed in from 2 to 4 weeks. Due to too long a delay in initiating the curative regime some animals succumbed within a day or two after its beginning, and thus served, along with others by design, as controls. Other controls proved the prolonged adequacy of the basal ration plus cabbage. None of these animals appears in the tables.

Four kinds of tea were tested in the form of infusions and the results are given in the following table. The preparation of the tea infusion was carried out as uniformly as possible. Fresh infusions were made daily; distilled water and glass flasks were used.