Vegetable oil
Vegetable oil or vegoil is fat extracted from plant sources. Although in principle other parts of plants may yield oil, in practice seeds form the almost exclusive source. Vegetable oils are used as cooking oils and for industrial uses. Some types, such as rapeseed oil, cottonseed oil, or castor oil, are not fit for human consumption without further processing.
Like all fats, vegetable oils are esters of glycerin and a varying blend of fatty acids, and are insoluble in water but soluble in organic solvents.
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Sources
Common sources of vegetable oil include:
Oilseeds:
- cashew
- castor bean - castor oil
- flax seed - linseed oil
- grape seed - grape seed oil
- hemp (cannabis)
- mustard
- poppy seeds - poppyseed oil
- rapeseed
- safflower - safflower oil
- sesame seed - sesame oil
- sunflower
Other vegetable oils:
- almond
- apricot
- avocado
- corn (maize)
- cotton plant seed - cottonseed oil
- coconut - coconut oil
- hazelnut
- neem oil
- olive - olive oil
- palm - palm oil - from the fruit of the African palm tree -
- palm kernel oil - from the seed of the African palm tree
- peanut - peanut oil
- pumpkin seed
- rice bran - used also in paints[1]
- soybean - soybean oil is sometimes marketed simply as "vegetable oil" in American grocery stores
- walnut
According to the USDA, the total world consumption of major vegetable oils in 2000 was:
| Soybeans | 26.0 million tonnes (MMT) |
| Palm | 23.3 MMT |
| Rapeseed | 13.1 MMT |
| Sunflowerseed | 8.6 MMT |
| Peanut | 4.2 MMT |
| Cottonseed | 3.6 MMT |
| Palm Kernel | 2.7 MMT |
| Olive | 2.5 MMT |
Note that these figures include industrial and animal feed use. Palm oil, which is solid at room temperature, is used mainly to produce soaps and cosmetics. The majority of European rapeseed oil production is used to produce biodiesel, or used directly as fuel in diesel cars which are modified to handle the higher viscosity.
Extraction
- One can use the "modern" way of processing oil by chemical extraction, using solvent extracts, which produces higher yields and is quicker and less expensive. The most common solvent is petroleum-derived hexane, more commonly known as petroleum ether.
- Another way is the "physical extraction", that does not use solvent extracts. It is made the "old" way by several different types of mechanical extraction. This method is frequently used to produce cooking oil, since it is preferred by most customers (at least in Europe). Expeller-pressed extraction is one type. There are two other types that are both oil presses. The screw press and the ram press.
See also
- biodiesel
- Straight vegetable oil (SVO)
- cooking oil
- decorticator
- expeller
- extruder
- lipid
- mill