Dry weight changes in Porto Rico sweet potatoes under actual storage conditions in Tennessee

Respiration is a necessary process common to all forms of living matter. Since the sweet potato root is living tissue, it too must respire in order to remain alive.

Basically, the respiratory process involves the oxidation of sugars or sugar derivatives to carbon dioxide and water by the living cell (3). Since after harvest the sweet potato has no new source of food materials, it must rely upon the stored carbohydrates it accumulated during the time it was growing. This sugar consumption by respiration results in a dry matter reduction, which coupled with a decrease in moisture, brings about an economically serious weight loss of the stored crop.

Accelerated rates of respiration are responsible for a more rapid loss of substrate. Thus high temperatures, which are often the cause of increased respiratory rates (3), result in increased weight losses. Cold storage of the crop is not satisfactory, however, because sweet potatoes exhibit chilling injury even when stored at temperatures of fifty degrees Fahrenheit for prolonged periods. Generally, recommendations suggest that the crop be stored at temperatures ranging from fifty to sixty degrees Fahrenheit following the short curing period immediately after harvest.

Environmental conditions under which the sweet potato crop is grown and harvested differ from state to state. Varieties differ in response to storage conditions as well. In consideration of these points, the purpose of the experiment here reported was to investigate the metabolic activity of the Porto Rico sweet potato under the influence of actual storage conditions in Tennessee.