African drying oils. I. The seed oil of tetracarpidum conophorum

The seed fat of Tetracarpidium conophorum is a drying oil (iodine value 200–205) the component acids of which are linolenic 64–68, linoleic 10–12, oleic 10–11, and saturated acids 10–12% (wt.). The high content of linolenic acid (which exceeds that (50–55%) in linseed oil) and the correspondingly high proportion (about 75%) of glycerides containing either two or three linolenic groups point to this oil as superior in drying properties to linseed oil. It forms a clear, hard film on exposure to air. The Tetracarpidium shrub is of fairly rapid growth and is already cultivated for native edible purposes in Southern Nigeria and adjacent regions; its development as a technical source of oil‐seed appears feasible. Since, however, the seed tissues are exceptionally rich in lipase, formation of free fatty acid proceeds rapidly in the dried kernels, and it will be essential to destroy the enzymes by heating the kernels at 100° before they are stored for export to this country or elsewhere for oil extraction.