Description and references
Obtained from soybeans by solvent extraction
using petroleum hydrocarbons or, to a lesser extent, by expression
using continuous screw press operations. Constit. Triglycerides
of oleic acid 26%, of linoleic acid 49%, of linolenic acid 11%, of
saturated acids 14%. Free fatty acids are usually less than 1%.
Phospholipids (lecithin) 1.5-4%. Another 0.8% consists of stigmasterol,
sitosterols, and tocopherols. The phospholipids and sterols are removed
by refining with alkali. Reviews and bibliographies: K. S. Markley, Soybeans and Soybean Products, 2 vols. (Interscience, New York,
1951); E. W. Eckey, Vegetable Fats and Oils (Reinhold, New York, 1954); W. J. Wolf in Kirk-Othmer Encyclopedia of Chemical Technology vol. 21 (Wiley-Interscience, New York, 3rd ed., 1983) pp 417-442.
Properties
Pale yellow to brownish-yellow oil. Slight characteristic
odor and taste. The flavor of crude soybean oil has been described
as paint-like and grass-like, and is somewhat distasteful to the palate
of occidentals. d2525 0.916-0.922. Flash pt 540°F (282°C). Ignition temp 833°F (445°C). nD25 1.471-1.475. Titer 22-27. Solidifies at 10 to 16°. Viscosity (cP):
172.9 (0°); 99.7 (10°); 50.09 (25°); 28.86 (40°). Acid value 0.3-3.0.
Saponification value 189-195. Iodine value 127-138. Thiocyanogen
value 77-85. Diene no. 0.7. Hydroxyl value 4-8. Reichert-Meissl
value 0.2-0.7. Polenske value 0.2-1.0. Miscible with abs alcohol,
ether, petr ether, chloroform, carbon disulfide.Use
Directly as food in the Orient, also in blends with
olive oil. In the manuf of margarine, shortenings, candy, soap.
In drying oil industries (paints, varnishes, linoleum, printing ink).
The foots or residue from refining has been used to obtain soybean
fatty acids which can be used in the manuf of alkyd resins.