The Stability of Carotene in Plant Tissues

Abstract

Chopped, artificially dried alfalfa hay, stored in bags in a barn, lost 50% of its carotene during the first 3 months of storage (late summer and early fall). There was no loss of carotene during the following winter but a further loss of 25% occurred during the succeeding summer season. No loss occurred during the second winter of storage. Storage of ball-milled, artificially dried alfalfa hay in vacuo in the dark at 0° ± 5°C. preserved the carotene very efficiently for 20 months. Both the exclusion of air and low temperature were important factors in the carotene preservation. The degree of fineness was of little importance. A.I.V. corn silage lost approximately 20% of its original carotene content during 5 months storage. In the case of A.I.V. alfalfa silage there was practically no loss in 5 months. Regular corn silage, during drying in vacuo over sulfuric acid, and storage in vacuo in the dark at 0° ± 5°C. lost carotene very rapidly. Biological assays on the hay stored in vacuo, and on a sample of regular corn silage, showed that the carotene content of these materials was a good index of their vitamin A potencies. In the case of the barn stored hay, the bio-assay gave relatively lower values. The data suggest that, as the carotene was destroyed during storage, a change also occurred in the remaining carotene which rendered it less potent biologically.