Palm oil
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Palm oil (also known as dendê oil, from Portuguese) is an edible vegetable oil derived from the mesocarp (reddish pulp) of the fruit of the oil palms, primarily the African oil palm Elaeis guineensis,[1] and to a lesser extent from the American oil palm Elaeis oleifera and the maripa palm Attalea maripa.
Palm oil is naturally reddish in color because of a high beta-carotene content. It is not to be confused with palm kernel oil derived from the kernel of the same fruit,[2] or coconut oil derived from the kernel of the coconut palm (Cocos nucifera). The differences are in color (raw palm kernel oil lacks carotenoids and is not red), and in saturated fat content: palm mesocarp oil is 41% saturated, while palm kernel oil and coconut oil are 81% and 86% saturated fats, respectively.
Along with coconut oil, palm oil is one of the few highly saturated vegetable fats and is semisolid at room temperature.[3]
Palm oil is a common cooking ingredient in the tropical belt of Africa, Southeast Asia and parts of Brazil. Its use in the commercial food industry in other parts of the world is widespread because of its lower cost[4] and the high oxidative stability (saturation) of the refined product when used for frying.[5][6]
The use of palm oil in food products has attracted the concern of environmental activist groups; the high oil yield of the trees has encouraged wider cultivation, leading to the clearing of forests in parts of Indonesia and Malaysia to make space for oil-palm monoculture.[7] This has resulted in significant acreage losses of the natural habitat of the orangutan, of which both species are endangered; one species in particular, the Sumatran orangutan, has been listed as critically endangered.[8] In 2004, an industry group called the Roundtable on Sustainable Palm Oil was formed to work with the palm oil industry to address these concerns.[9] Additionally, in 1992, in response to concerns about deforestation, the Government of Malaysia pledged to limit the expansion of palm oil plantations by retaining a minimum of half the nation's land as forest cover.[10][11]
History[edit]
Human use of oil palms may date as far back as 5,000 years; in the late 1800s, archaeologists discovered a substance that they concluded was originally palm oil in a tomb at Abydos dating back to 3,000 BCE.[12] It is believed that Arab traders brought the oil palm to Egypt.[13] Some argue that it is not possible that Arab traders could have brought the oil palm to ancient Egypt, as the Arabs did not settle in Africa until the 8th century CE. It is more likely that the oil palm was brought to Ancient Egypt (Kemet) by its founding peoples who migrated from other regions of the African continent.[14]
Palm oil from E. guineensiss has long been recognized in West and Central African countries, and is widely used as a cooking oil. European merchants trading with West Africa occasionally purchased palm oil for use as a cooking oil in Europe.
Palm oil became a highly sought-after commodity by British traders, for use as an industrial lubricant for machinery during Britain's Industrial Revolution.[15]
Palm oil formed the basis of soap products, such as Lever Brothers' (now Unilever) "Sunlight" soap, and the American Palmolivebrand.[16]
By around 1870, palm oil constituted the primary export of some West African countries, such as Ghana and Nigeria, although this was overtaken by cocoa in the 1880s.[citation needed]
Composition[edit]
Fatty acids[edit]
Main article: Fatty acid
Palm oil, like all fats, is composed of fatty acids, esterified with glycero
The approximate concentration of fatty acids in palm oil is:[19]
| Fatty acid content of palm oil | ||||
|---|---|---|---|---|
| Type of fatty acid | pct | |||
| Myristic saturated C14 | 1.0% | |||
| Palmitic saturated C16 | 43.5% | |||
| Stearic saturated C18 | 4.3% | |||
| Oleic monounsaturated C18 | 36.6% | |||
| Linoleic polyunsaturated C18 | 9.1% | |||
| Other/Unknown | 5.5% | |||
| black: Saturated; grey: Monounsaturated; blue: Polyunsaturated | ||||
Carotenes[edit]
Red palm oil is rich in carotenes, such as alpha-carotene, beta-
Processing and use[edit]
Many processed foods either contain palm oil or various ingredients derived from it.[21]
Refining[edit]
See also: Cooking oil refinement
After milling, various palm oil products are made using refining processes. First is fractionation, with crystallization and separation processes to obtain solid (stearin), and liquid (olein) fractions.[22] Then melting and degumming removes impurities. Then the oil is filtered and bleached. Physical refining[clarification needed] removes smells and coloration to produce "refined, bleached and deodorized palm oil" (RBDPO) and free sheer fatty acids,[clarification needed] which are used in the manufacture of soaps, washing powder and other products. RBDPO is the basic palm oil product sold on the world's commodity markets. Many companies fractionate it further to produce palm olein for cooking oil, or process it into other products.[22]
Red palm oil[edit]
Since the mid-1990s, red palm oil has been cold-pressed and bottled for use as cooking oil, and blended into mayonnaise and salad oil.[23]
Butter and trans fat substitute[edit]
The highly saturated nature of palm oil renders it solid at room temperature in temperate regions, making it a cheap substitute for butteror trans fats in uses where solid fat is desirable, such as the making of pastry dough and baked goods. A recent rise in the use of palm oil in the food industry has partly come from changed labelling requirements that have caused a switch away from using trans fats.[24]Palm oil has been found to be a reasonable replacement for trans fats;[25] however, a small study conducted in 2009 found that palm oil may not be a good substitute for trans fats for individuals with already-elevated LDL levels.[26] The USDA
Biomass and bioenergy[edit]
Palm oil is used to produce both methyl ester and hydrodeoxygenated biodiesel.[
The organic waste matter that is produced when processing oil palm, including oil palm shells and oil palm fruit bunches, can also be used to produce energy. This waste material can be converted into pellets that can be used as a biofuel.[31] Additionally, palm oil that has been used to fry foods can be converted into methyl esters for biodiesel. The used cooking oil is chemically treated to create a biodiesel similar to petroleum diesel.[32]
Nutrition and health[edit]
Much of the palm oil that is consumed as food is cooking oil, to some degree oxidized rather than in the fresh state, and this oxidation appears to be responsible for the health risk associated with consuming palm oil.[60]
Palmitic acid[edit]
According to studies reported on by the Center for Science in the Public Interest (CSPI), excessive intake of palmitic acid, which makes up 44 percent of palm oil, increases blood cholesterol levels and may contribute to heart disease.[61] The CSPI also reported that the World Health Organization and the US National Heart, Lung and Blood Institute have encouraged consumers to limit the consumption of palmitic acid and foods high in saturated fat.[57][61] According to the World Health Organization, evidence is convincing that consumption of palmitic acid increases risk of developing cardiovascular diseases, placing it in the same evidence category as trans fatty acids.[62]
Comparison to trans fats[edit]
In response to negative reports on palm oil many food manufacturers transitioned to using hydrogenated vegetable oils in their products, which have also come under scrutiny for the impact these oils have on health.[63] A 2006 study supported by the National Institutes of Health and the USDA Agricultural Research Service concluded that palm oil is not a safe substitute for partially hydrogenated fats (trans fats) in the food industry, because palm oil results in adverse changes in the blood concentrations of LDL cholesterol and apolipoprotein B just as trans fat does.[26][64] However, according to two reports published in 2010 by the Journal of the American College of Nutrition palm oil is again an accepted replacement for hydrogenated vegetable oils[63] and a natural replacement for partially hydrogenated vegetable oils, which are a significant source of trans fats.[65]
Comparison with animal saturated fat[edit]
Not all saturated fats have equally cholesterolemic effects.[66] Studies have indicated that consumption of palm olein (which is more unsaturated) reduces blood cholesterol when compared to sources of saturated fats like coconut oil, dairy and animal fats.[66][67]
Acrolein[edit]
A 2009 study[68] tested the emission rates of acrolein, a toxic and malodorous breakdown product from glycerol, from the deep-frying of potatoes in red palm, olive, and polyunsaturated sunflower oils. The study found higher acrolein emission rates from the polyunsaturated sunflower oil (the scientists characterized red palm oil as "mono-unsaturated") and lower rates from both palm and olive oils. The World Health Organization established a tolerable oral acrolein intake of 7.5 mg/day per kilogram of body weight. Although acrolein occurs in French fries, the levels are only a few micrograms per kilogram. A 2011 study concluded a health risk from acrolein in food is unlikely.[69]
Social and environmental impacts[edit]
Main article: Social and environmental impact of palm oil
Social[edit]
The palm oil industry has had both positive and negative impacts on workers, indigenous peoples and residents of palm oil-producing communities. Palm oil production provides employment opportunities, and has been shown to improve infrastructure, social services and reduce poverty.[70][71][72] However, in some cases, oil palm plantations have developed lands without consultation or compensation of the indigenous people occupying the land, resulting in social conflict.[73][74][75] The use of illegal immigrants in Malaysia has also raised concerns about working conditions within the palm oil industry.[76][77][78]
Some social initiatives use palm oil cultivation as part of poverty alleviation strategies. Examples include the UN Food and Agriculture Organisation's hybrid oil palm project in Western Kenya, which improves incomes and diets of local populations,[79] and Malaysia's Federal Land Development Authority and Federal Land Consolidation and Rehabilitation Authority, which both support rural development.[80]
Food vs. fuel[edit]
Main article: Food vs. fuel
The use of palm oil in the production of biodiesel has led to concerns that the need for fuel is being placed ahead of the need for food, leading to malnourishment in developing nations. This is known as the food versus fuel debate. According to a 2008 report published in the Renewable and Sustainable Energy Reviews, palm oil was determined to be a sustainable source of both food and biofuel. The production of palm oil biodiesel does not pose a threat to edible palm oil supplies.[81] According to a 2009 study published in the Environmental Science and Policy journal, palm oil biodiesel might increase the demand for palm oil in the future, resulting in the expansion of palm oil production, and therefore an increased supply of food.[82]
Environmental[edit]
See also: 2015 Southeast Asian haze
Palm oil cultivation has been criticized for impacts on the natural environment,[83][84]including
Efforts to portray palm oil cultivation as sustainable have been made by organizations including the Roundtable on Sustainable Palm Oil,[91] an industry group, and the Malaysian government, which has committed to preserve 50 percent of its total land area as forest.[10]According to research conducted by the Tropical Peat Research Laboratory, a group studying palm oil cultivation in support of the industry,[92] oil palm plantations act as carbon sinks, converting carbon dioxide into oxygen[93] and, according to Malaysia's Second National Communication to the United Nations Framework Convention on Climate Change, the plantations contribute to Malaysia's status as a net carbon sink.[94]
Environmental groups such as Greenpeace and Friends of the Earth oppose the use of palm oil biofuels, claiming that the deforestationcaused by oil palm plantations is more damaging for the climate than the benefits gained by switching to biofuel and utilizing the palms as carbon sinks.[90][95][96]
While only 5 percent of the world's vegetable oil farmland is used for palm plantations, palm cultivation produces 38 percent of the world's total vegetable oil supply.[97] In terms of oil yield, a palm plantation is 10 times more productive than soya bean and rapeseed cultivation because the palm fruit and kernel both provide usable oil.[97]
