Food
Soybean oil is mostly used for frying and baking. It is also used as a condiment for salads.
Comparative properties of common cooking fats (per 100g)
Total Fat Saturated Fat Monounsaturated Fat Polyunsaturated Fat Smoke Point
Vegetable Shortening (hydrogenated) 71g 23g 8g 37g 182°C (360°F)
Sunflower oil 100g 11g 20g 69g 232°C (450°F)
Soybean oil 100g 16g 23g 58g 232°C (450°F)
Peanut oil 100g 17g 46g 32g 232°C (450°F)
Olive oil 100g 14g 73g 11g 216°C (420°F)
Lard 100g 39g 45g 11g 188°C (370°F)
Suet 94g 52g 32g 3g 200°C (400°F)
Butter 81g 51g 21g 3g 177°C (350°F)
Drying oil
Soybean oil will slowly harden on exposure to air, forming a flexible, transparent, and waterproof solid. For this reason, it is used in some printing ink and oil paint formulations.
Fixative for insect repellents
While soybean oil has no direct insect repellent activity, it is used as a fixative to extend the short duration of action of essential oils such as geranium oil in several commercial products.
Production
To produce soybean oil, the soybeans are cracked, adjusted for moisture content, heated to between 140°F and 190°F, rolled into flakes, and solvent-extracted with hexane. The oil is then refined, blended for different applications, and sometimes hydrogenated. Soybean oils, both liquid and partially hydrogenated, are exported abroad, sold as "vegetable oil," or end up in a wide variety of processed foods. Most of the remaining residue (soybean meal) is used as animal feed.
In the 2002–2003 growing season, 30.6 million tons of soybean oil were produced worldwide, constituting about half of worldwide edible vegetable oil production, and thirty percent of all fats and oils produced, including animal fats and oils derived from tropical plants.
Composition
See also: trans fat
100g of soybean oil has 16g of saturated fat, 23 g of mono unsaturated fat, and 58g of poly unsaturated fat. The major unsaturated fatty acids in soybean oil triglycerides are 7–10% alpha-Linolenic acid (C-18:3); 51% linoleic acid (C-18:2); and 23% oleic acid (C-18:1). It also contains the saturated fatty acids 4% stearic acid and 10% palmitic acid which are long chain saturated fatty acids.
The high-proportion of oxidation-prone linolenic acid is undesirable for some uses, such as cooking oils in restaurants. In the early nineties, Iowa State University developed soybean oil with 1% linolenic acid. Three companies, Monsanto Company, DuPont/Bunge, and Asoyia in 2004 introduced low linolenic Roundup Ready soybeans. In the past, hydrogenation was used to reduce the unsaturation in linolenic acid, but this produced the unnatural trans-fatty acid configuration, whereas in nature the configuration is cis. This external picture from North Dakota State University compares soybean oil fatty acid content with other oils.
Soybean oil is a vegetable oil extracted from the seeds of the soybean (Glycine max). It is one of the most widely consumed cooking oils. Being one of the drying oils,it is also used as a base for printing inks and oil paints.
