The Vitamin B and Vitamin G Content of Bosc Pears. Use of the Munsell Method of Assaying Foods for Vitamin G

Abstract

The vitamin B complex, vitamin B and vitamin G, of Bosc pears has been studied and tentative units for each are suggested. Expressed as the quantity of dried pear yielding one Sherman unit, 1.21 gm. (10.03 gm. fresh pear) will yield 1 unit of vitamin B complex. Translating this in terms of units per ounce, 1 ounce of fresh pear furnishes 2.8 units of vitamin B complex. As a source of vitamin B, 0.73 gm. dried Bosc pear (6.0 gm. fresh pear) furnishes 1 unit of vitamin B, or 1 ounce fresh pear furnishes 4.7 units of vitamin B. As a source of vitamin G, 0.59 gm. of dried pears (4.64 gm. of fresh pear) contains 1 unit of vitamin G, or 1 ounce of fresh pear furnishes 6.1 units of vitamin G. It appears, therefore, that Bosc pears are a somewhat richer source of vitamin G than vitamin B. Results show that white corn, when fed as 30 per cent of basal diet B, supplied enough vitamin B to prevent symptoms of polyneuritis and vitamin B deficiency, but does not supply enough vitamin G to promote more than very slight growth (1.9 gm. weekly). Autoclaved yeast at pH 5 when fed at a 0.5 gm. level, supplemented the 30 per cent white corn in vitamin G and normal growth was obtained on this level. When vitamin B is adequately supplied by white corn, vitamin G is furnished by Bosc pear in the same ratio as the quantity of pear supplied in the diet. In laboratories not equipped to prepare extracts of vitamin B for use in the assaying of foods for vitamin G, fairly satisfactory results may be obtained by use of the Munsell method in which white corn furnishes the vitamin B.