Soybean oil 

Soybean oil is widely used oil and is commonly called vegetable oil which is extracted from the seeds of the soybean (Glycine max). It is one of the most widely consumed cooking oils. soya bean oil doesn’t contains much saturated fats. It is one of the stable cooking oils; having a long shelf life. Soybean oil is very popular with rich value of Omega 3 and Omega 6. Those fatty acids regulate lipid and cholesterol metabolism and prevent narrowing in artery veins. As a drying oil, processed soybean oil is also used as a base for printing inks (soy ink) and oil paints. Soybeans owe their dominance of the oilseed market to the value of their protein, which is much greater than that of other oilseeds. Soybean oil of typical composition performs well as a salad oil, but it is usually hydrogenated for use as a margarine stock or frying oil. Soybean oil is the primary commercial source of alphatocopherol, also known as vitamin E.

Composition:

Per 100 g, soybean oil has 16 g of saturated fat, 23 g of monounsaturated fat, and 58 g of polyunsaturated fat. The major unsaturated fatty acids in soybean oil triglycerides are the polyunsaturates alpha-linolenic acid (C-18:3), 7-10%, and linoleic acid (C-18:2), 51%; and the monounsaturate oleic acid (C-18:1), 23%. It also contains the saturated fatty acids stearic acid (C-18:0), 4%, and palmitic acid (C-16:0), 10%.100 g oil provides 884 calories.

Physical characteristics :

Dry soybean seeds compose about 18-20% of extractable oil by weight. The seeds are then subject to pressing to obtain oil and the residue soybean meal which is used as animal feed. Crude soybean oil is deep yellow in color and contains impurities such as moisture, lecithin, free-fatty acids, and certain volatile compounds. These impurities are removed through further refininement to obtain acceptable standard oil. Refined oil is clear light yellow liquid, and features neutral odor and taste. Fresh oil has very low free fatty acids (FFA) less than 0.1%. Its specific gravity @ 25 °C is 0.9150–0.9280, Iodine value-75 – 94, and saponification value-184 – 195.

Uses:

Food uses : Salad Dressing Baked goods Crackers Barbecue sauce

Shortening Non-Dairy Creamers Potato chips Mayonnaise Breads Whipped Toppings

Non-food use of soybean oil: used as renewable raw material to produce a variety of non-food products like

Bio diesel Inks Plasticizers Crayons Paints Soy candles

Health benefits of soybean oil

Soybean oil is chiefly a poly-unsaturated fats rich vegetable oil. Linoleic acid (omega-6) is the major poly-unsaturated fatty acid found in it. Additionally it is low in saturated fats, and free from cholesterol; making it as one of the healthiest cooking oils.

Soybean, being a vegetable oil, is a good source of plant sterols, especially  -sitosterolβ .  The FDA has approved the following claim for phytosterols: "Foods containing at least 0.4 gram per serving of plant sterols, eaten twice a day with meals for a daily total intake of at least 0.8 gram, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease." Phyto-sterols competitively inhibit cholesterol absorption in the gut and thereby can reduce blood cholesterol levels by 10% to 15%.

Soybean oil is a moderate source of anti-oxidant vitamin E. 100 g fresh oil has 8.18 mg of -αtocopherol and 64.26 mg of gamma-tocopherol. Vitamin E is a powerful lipid soluble antioxidant, required for maintaining the integrity of cell membrane of mucus membranes and skin by protecting it from harmful oxygen-free radicals.

The oil has vitamin K in high concentrations; 100 g of oil compose of 183.9 mcg. Vitamin K has potential role bone health by promoting osteotrophic (bone formation and strengthening) activity. Adequate vitamin-K levels in the diet help limiting neuronal damage in the brain; thus, has established role in the treatment of patients suffering from Alzheimer's disease.

Production:

The production of commercial soybean oil is complicated. The mechanical production of soybean oil with hydraulic presses is not much used because it’s expensive and gives lower yields. Soybean oil is normally produced by extraction with solvents. The production consists of following steps:

Cleaning of Soyabeans:

The soybeans are first cleaned, dried and dehulled prior to oil extraction. The soybean hulls needs to be removed because they absorb oil and give a lower yield. This de-hulling is done by cracking the soybeans and a mechanical separation of the hulls and cracked soybeans. Magnets are used to separate any iron from the soybeans. The soybean are also heated to about 75ₒC to coagulate the soy proteins to make the oil extraction easier.

Extraction of soybean oil

First the soybeans are cut in flakes which are put in a percolation extractors and immerged with a solvent, normally hexane. Counterflow is used as extraction system because it gives the highest yield. After removing the hexane, the extracted flakes only contain about 1% of soybean oil and is used as livestock meal or to produce food products such as soy protein. The hexane is separated from the soybean oil in evaporators. The evaporated hexane is recovered and returned to the extraction process. The hexane free crude soybean oil is then further purified. In India, crushing of soybean for soy oil and meal starts from October and it peaks during the subsequent two-three months.

Purification of soybean oil

The crude soybean oil still contains many oil-insoluble and oil-soluble impurities that needs to be removed. The oil-insoluble material are removed with filtration and the soluble materials is removed with different processes including degumming (removing of phosphatides), alkali refining (washing with alkaline solution to remove free fatty acids, colorants, insoluble matter and gums) and bleaching (with activated earth or activated carbon to remove colour and other impurities.

Hydrogenation of soybean oil (optional)

This process will increase the stability of the soybean oil and will make it less liquid. However, this process will create more saturated fats and will reduce the favourable unsaturated fats. In addition, transfats are produced which can cause hearth problems. Hydrogenated soybean oil is used in foods that require more solid fat such as margarines.

Major International Exchanges for Soy Oil Trade

Chicago Board of Trade (CBOT) The South African Futures Exchange (SAFEX) Dalian Commodity Exchange (DC) Kansai Commodities Exchange (KEX) in Japan Tokyo Grain Exchange (TGE) in Japan’

Production of soyabean oil:

China, United States, Argentina and Brazil are the key producers of Soybean oil in 2014- 15.

India’s share in global production of Soybean Oil in 2014-15 is around 4.13 percent.

Major Exporting Countries:

Argentina is the largest exporting country in the world followed by Brazil, EU, and the US during 2014-15

Major Importing Countries of Soyabean oil:

India is the largest importer of soybean oil that constituted 17.55 percent of the global import in the year 2014-15.