This section is from the book "A Practical Treatise On Friction, Lubrication, Fats And Oils", by Emil F. Dieterichs. Also available from Amazon: A practical treatise on friction, lubrication, fats and oils.
Obtained from the seeds of Sesamum Jndicum of India and from the seeds of the plant cultivated in southern Europe and the Orient.
The seeds furnish from 40 to 50 per cent of oil of a bright yellowish color and agreeably sweet taste. It is much used as a substitute and adulterant of olive oil, and is very similar to it in its characteristics. Its specific gravity at 60° F. is 0.9235, or 22° Baume.
Cottonseed oil is obtained from the seeds of the cotton plant. The seeds contain from fifteen to twenty per cent, of oil, a thickish liquid of a straw-yellow color, with nut-like taste and smell. It is of a semi-drying character, consists of palmitin and olein, and is from twenty-eight to thirty times less fluid than water. Like all the oils obtained from seeds, the latter are first slightly roasted and separated from their outside shells by mechanical power, and the oil is secured by pressure or by extraction with solvents.
The specific gravity of cottonseed oil is 0.9206 at 60° F., or 20° Baume. It separates palmitin and stearin at about 55° F., and solidifies at about 40° F.
Rape or colza oil is produced from rapeseed, turnips, and other species of Brassica. It is obtained from the seeds by cold and hot pressure, and they yield from thirty to forty-five per cent of oil. The first pressings are known under the name of colza oil; the second pressings are usually sold as rapeseed oil. Colza oil has a pale yellow color; rapeseed oil a greenish-brown color. They are limpid oils, with a peculiar and characteristic odor, and an unpleasant and harsh taste. Exposed to the air, the oil becomes more viscid. Its specific gravity at 60° F. ranges from 0.913 to 0.915, or 23° Baume. It is a semi-drying and gumming oil.
Hempseed oil is obtained from the seeds of the Cannabis Indica plant. The seeds when crushed have a peculiar odor, and yield by pressure or extraction from thirty to thirty-five per cent of an oil of a greenish-yellow color. The oil remains fluid to 10° F., and thickens when cooled down to 5° F., to a brownish-yellow mass. Its specific gravity is 0.9276, or 21° Baume, at 60° F., and about 0.9240 at 70° F.
The oil consists of lineolic acid, oleic acid and palmitin and stearic acids. It is somewhat less drying than linseed oil.
Palm oil is obtained from the fruit of the oil palm and the cocoanut palm of tropical Africa, and is known as palm fat, palm butter or palm oil. The oily pulp of the fruit of the oil palm, after being bruised and boiled in water, yields an oil which, when fresh, has a pleasant odor of violets, and assumes in the cold the consistency of butter of an orange-yellow to a dirty, reddish color.
From the dried kernels of the cocoanut (copra) a fixed oil is extracted, which is the cocoanut oil of commerce. The kernels are ground, and the resulting paste is boiled with water. The paste is then submitted to high pressure, whereby a large quantity of milky juice is obtained. This is boiled, and when the oil separates from the water it is skimmed off.
Palm oil or palm butter consists chiefly of stearin and palmitin, both of which have a comparatively high fusing point of about 115° to 120° F., and are preponderant in the solid fat, while olein, which is fluid at 32° F., is the chief constituent of the oil.
The specific gravity is 0.968, or 15° Baume.
Cocoanut oil is of a bright white color. Its specific gravity is .952, or 17° Baume.
Almond oil is obtained from the kernels of bitter and sweet almonds, the seeds of the almond plant, The sweet almonds contain more fatty oil than the bitter almonds. The almonds contain from forty-five to fifty-five per cent of oil. For pressing the bitter and sweet almonds are mixed. The oil obtained is a thick liquid, little affected by cold, possesses a purely oleaginous taste and solidifies at 5° F. to a buttery mass. Almond oil is more limpid than olive oil and is thicker than poppyseed oil. It consists almost of pure olein. Its specific gravity is about 0.917 or 23° Baume.
Poppyseed oil is obtained from the seeds of the poppyflower by cold and by warm pressure. It is imported from India and the plant is largely cultivated in France and Southern Europe. The seeds yield about forty-seven to fifty-five per cent of oil of a pale-yellow to a gold-yellow color. It is a clear, limpid oil, with an agreeable taste and a peculiar, slight odor, somewhat like olive oil. Its specific gravity at about 60° F. is 0.9250 or 21° Baume. It remains liquid until cooled down to 0° F. when it forms a thick, whitish mass. Once solidified by cold, it remains solid to about 30° F., when it begins rapidly to become liquid again. Poppyseed oil is almost as quick drying as linseed oil, and is composed of linolein, oleic, stearic and palmitic acids.
Corn oil is obtained from the kernels of the corn (maize) plant, and is almost entirely found in the shells of the kernels.
To separate the shells from the farinaceous part of the kernels, and to make the latter better available for the mashing process, the kernels are first subjected to the malting process. They are then crushed and the shells separated from the farinaceous part by a sifting or centrifugal operation, whereby the parts of lighter specific gravity are easily separated from the heavier ones, nearly eighty per cent of cornmeal, almost entirely free from oily matter, being thereby obtained. Otherwise the oily matter would greatly interfere with the fermentation of the mash, and impart an unpleasant flavor to the alcohol manufactured therefrom.
The hulls thus separated are subjected to heavy pressure, and about fifteen per cent of pure corn oil obtained.
Corn oil is of a light to a gold-yellow color, and has a peculiar, agreeable odor. It is a thickish liquid of 0.9215, or 22° Baume at 60° F. It is composed of oleic, stearic and palmitic acids, with a small percentage of a volatile oil, and solidifies at about 50° to 60° F. to a quite solid, white mass. It is used as a wool oil, for the manufacture of soaps, and in the manufacture of lubricating oils.