Soybean oil is a popular vegetable oil extracted from the soybean. Soyabean oil is valued for its economical, high smoke point and health benefits. Soyabean oil has a faint green or dark yellow color. Soybean oil accounts for 80% of all commercial oil used in the United States. So, the oil of soyabean is all rounder oil, which is used as frying medium, baking and cooking purposes.
The process of obtaining soybean oil is through extraction from the soybean. The beans are cracked beans and then heating the beans to remove any unnecessary moisture. After that, the beans are sliced and then rolled to extract the oil from beans. Generally, commercial brands mix the soybean oil with other cheaper oils to make it more economical. The unrefined oils have a stronger flavor as compared to refined oil, but unrefined oil usually retains a higher nutritional value than refined oils.
Soybean is the dominant oilseed produced in the world, due to its favourable agronomic characteristics, good quality proteins, and produces valuable edible oil. Soyabean contributes over a half of all oilseeds produced worldwide. The production of soybeans and soybean oil is driven by the need for protein meal that is used mostly in commercial feeds for cattle, swine and poultry. Soybean oil has many desirable compositional and functional properties. The oil of soybean is the predominant vegetable oil produced globally, with palm oil being the second.
Soybean oil is produced in largest quantity and is second to palm oil in traded oil. The major producers of soybean oil are the Argentina, Brazil, US, India, China and EU-15. Consumption of soybean oil is seen in every country. Disappearance is generally greatest in the producing countries with five countries/regions exceeding one million tonnes. These are the US (28%), China (13%), Brazil (12%), India (7%), and EU-15 (7%). Argentina is the biggest exporter of soybean oil (43% of total soybean oil exports).The import of soybean oil in India was 1.47 million tonnes in 2000 as shown in table below. The import of soyabean oil goes to the highest 2.026 million tonnes in 2004 with a growth rate of 123.62 %, later on it showed a reduction in the growth rate. As shown in the table below the minimum growth rate of soyabean oil was in the year 2007 (-49.34 %). In 2008-09 it showed a rise in growth rate. In the last year 2014, the quantity of import was 1.85 million tonnes with a growth rate of 1.09 %.
Table 1 India’s soyabean oil import by year
Extraction of soybean oil The two common processes for soybean oil extraction are solvent extraction and mechanical pressing but in the US, soybeans are processed by mechanical means only less than 1%. Extraction by solvent like hexane is the standard practice in today’s modern processing facilities. There are three major steps involved in solvent extraction these include seed preparation, extraction of oil, and desolventizing of the oil and meal. The conventional seed preparation involves drying to get rid of moisture, cleaning to remove impurities, cracking, optional dehulling, conditioning of seeds and flaking of the seeds. The choice of expanding after flaking is used to improve solvent drainage, percolation and oil extraction, and is accompanied by a doubling of the throughput. The other ways of seed preparation (hot dehulling), the hulls are removed from the split seeds by alternate slow and rapid heating before cracking and flaking. However in the US the majority of soybean oil is chemically refined.
Solvent (hexane) extraction of soybeans is a diffusion process achieved by immersing solid in solvent or by percolating solvent through a bed of solids. Horizontal belt, rotary (deep-bed) and continuous loop extractors are used for soybeans. Solvent is recovered from the mixture of solvent and extracted oil (miscella) by double-effect evaporator and steam stripping and from flake by a desolventizer–toaster and is then recycled.
The two major mechanical processes for soybeans are continuous screw pressing with extensive heating and extrusion-expelling. Extrusion-expelling technology is used increasingly for processing identity preserved seeds for niche market soybean oil and protein products. The advantages of small tonnage requirement (easy switchover for various different types of seeds, low initial capital investment, no flammable solvent used and unique products) have made this processing technology very appealing for many soybean growers and processors.
Food uses of soybean oil Soybean oil is often used to make margarine, salad dressing, mayonnaise and non-dairy coffee creamers. Because of the high smoke point of soybean oil, it is often used for frying purposes. The smoke point of soybean oil is found to be 450 degrees. The shelf life of soybean oil has been found to be one year. Soyabean oil should be stored in a dark place, dry and kept away from hot places. Soybean oil can also be stored in the refrigerating conditions. Soybean oil is popular oil for cooking because it is so versatile and it has a bland flavor that will not interfere with cooking or baking.
When purchasing soybean oil, consider buying unrefined soybean oil so that you can obtain all the health benefits this oil provides without any of the negative side effects from the added trans fat. According to Agricultural Statistics 2000 (USDA–NASS 2000, soybean oil was used to produce 95% of the total margarine and 83% of the total shortening. It has been found that 95% of the total soybean oil produced was used in food applications. Among the food uses, 13, 38 and 48% of the soybean oil was used in margarine, shortening, and cooking oil, respectively. Most important uses of soyabean oil are
1. Cooking and salad oils
2. Margarine and shortening
3. Mayonnaise and salad dressing
Health Benefits of Soybean Oil The cholesterol level in soyabean is negligible that makes it a perfect choice for persons with heart disease or high cholesterol level. Soybean oil is composed of polyunsaturated fats that have the ability to reduce total cholesterol level, lower low density lipids or bad cholesterol levels and increase high density lipids or good cholesterol levels. The oil of soybean is possessed with omega-3 fatty acids that have shown to decrease the risk of heart disease, lower the growth of atherosclerotic plaque, lower the risk of arrhythmias or abnormal heartbeats and reduces triglyceride levels. Naturally antioxidants have been found soyabean, which remain in the oil even after it is pressed or extracted. These antioxidants protect from the damage caused by free radicals that may help prevent certain cancers.
Nutritional Value per 1 tablespoon of soybean oil: 120 calories
13.6 g fat
1.96 g saturated fat
7.87 polyunsaturated fat
3.17 monounsaturated fat
0 mg cholesterol
0 mg sodium
0 mg potassium
0 g carbohydrates
0 g fiber
0 g protein
1 tablespoon of soybean oil is contained with 6% of daily recommended value of vitamin E.
Negative Effects of Soybean Oil For the increase of shelf life many commercial brands of soybean oil are often hydrogenated. This hydrogenation process makes Trans fats to the soybean oil that increases the cholesterol of the product. Using soybean oil with Trans fat may increase the risk of certain kind of heart diseases.
Global supply demand estimates The major soy meal exporting countries are
1. Argentina (20 MT)
2. Brazil (15 MT)
3. USA (6MT)
4. India (4 MT)
5. European union (3 MT)
The major importers of soy meal are
1. European union (22 MT)
2. Central Europe (3.5 MT)
3. Thailand (2MT)
4. South Korea (1.5 MT)
5. Indonesia (1.5 MT)
6. Japan (1MT)
7. Philippines (1 MT)
8. Canada (1 MT)
India is fifth largest producer of soyabean in the world, with average production of 4809 TMT of soyabean. Average consumption is 4812 TMT of soyabean. Currently India produces 6 MMT per annum. Soyabean has doubled in the last ten years.