AbstractsChemistry

In 1920 Hopkins (1) demonstrated that vitamin A was inactivated in the presence of atmospheric oxygen at elevated temperatures, although little or no effect could be observed at room temperatures or in the absence of air. During the same year Drummond and Coward (2) showed that butter exposed to air at 37°C lost a considerable portion of its vitamin A potency. Frequent confirmations of this early work have been obtained both for vitamin A itself and for its precursors, although the latter are apparently more stable than is the actual vitamin (3). [...]