Palm oil is an edible plant oil and is derived from the mesocarp of the fruit of the oil palm (Elaeis guineensis).[1] 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 respectively [3]
Naturally reddish in color because of a high beta-carotene content, palm oil, along with coconut oil, is one of the few highly saturated vegetable fats. It is semi-solid at room temperatures and contains several saturated and unsaturated fats in the forms of glyceryl laurate (0.1%, saturated), myristate (1%, saturated), palmitate (44%, saturated), stearate (5%, saturated), oleate (39%, monounsaturated), linoleate (10%, polyunsaturated), and alpha-linolenate(0.3%, polyunsaturated).[4] Like all vegetable oils, palm oil does not contain cholesterol,[5][6] although saturated fat intake increases both LDL[7] andHDL[8] cholesterol.
Palm oil is a common cooking ingredient in the tropical belt of Africa, Southeast Asia and parts of Brazil. Its increasing use in the commercial food industry in other parts of the world is buoyed by its lower cost[9] and the high oxidative stability (saturation) of the refined product when used for frying.[10][11]
The use of palm oil in food products attracts the concern of environmental activist groups; the high oil yield of the trees have led, in parts of Indonesia, to removal of forestry in order to make space for oil-palm monoculture. This has resulted in acreage losses of the natural habitat of the orangutan.[12]Consumer pressure could encourage palm oil companies to modify their practices. The Roundtable on Sustainable Palm Oil, an international non-profit association, that brings together conservation groups and palm-oil firms, says that it "will not certify oil grown on land that was deforested to farm the crop".[13]
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[edit]History
Palm oil (from the African oil palm, Elaeis guineensis) has long been recognized in West 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, but palm oil was not able to supplant olive oil or butter, and culinary uses of palm oil remained rare outside West Africa until after commercial oil palm plantation development in non-African tropical regions. In the Asante Confederacy, state-owned slaves built large plantations of oil palm trees, while in the neighbouring Kingdom of Dahomey, King Ghezopassed a law in 1856 forbidding his subjects from cutting down oil palms.
Palm oil became a highly sought-after commodity by British traders, for use as an industrial lubricant for machinery during Britain's Industrial Revolution.[14]Palm oil formed the basis of soap products, such as Lever Brothers' (now Unilever) "Sunlight" soap, and the American Palmolive brand.[15] 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]
[edit]Research
In the 1960s, research and development (R&D) in oil palm breeding began to expand after Malaysia's Department of Agriculture established an exchange program with West African economies and four private plantations formed the Oil Palm Genetics Laboratory.[16] The government also established Kolej Serdang, which became the Universiti Pertanian Malaysia (UPM) in the 1970s to train agricultural and agro-industrial engineers and agro-business graduates to conduct research in the field.
In 1979, following strong lobbying from oil palm planters and support from the Malaysian Agricultural Research and Development Institute (MARDI) and UPM, the government set up the Palm Oil Research Institute of Malaysia (Porim).[17] B.C. Sekhar was instrumental in helping Porim recruit and train scientists to undertake R&D in oil palm tree breeding, palm oil nutrition and potentialoleochemical use. Sekhar, as founder and chairman, pushed Porim to be a public-and-private-coordinated institution. As a result, Porim (renamed Malaysian Palm Oil Board in 2000) became Malaysia's top research entity commercializing 20% of its innovations, compared to 5% among local universities.[citation needed]
[edit]Nutrition
Further information: palmitic acid
Many processed foods contain palm oil as an ingredient.[18]
Palm oil is composed of fatty acids, esterified with glycerol just like any ordinary fat. It is high in saturated fatty acids. Palm oil gives its name to the 16-carbon saturated fatty acid palmitic acid. Monounsaturated oleic acid is also a constituent of palm oil. Unrefined palm oil is a large natural source of tocotrienol, part of the vitamin E family.[19]
The approximate concentration of fatty acids in palm oil is:[20]
[edit]Red palm oil
Red palm oil gets its name from its characteristic dark red color, which comes from carotenes, such as alpha-carotene, beta-carotene and lycopene, the same nutrients that give tomatoes, carrots and other fruits and vegetables their rich colors.
Red palm oil contains at least 10 other carotenes, along with tocopherols and tocotrienols (members of the vitamin E family), CoQ10, phytosterols, and glycolipids.[21] In a 2007 animal study, South African scientists found consumption of red palm oil significantly decreased p38-MAPK phosphorylation in rat hearts subjected to a high-cholesterol diet.[22]
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] Red palm oil antioxidants like tocotrienols and carotenes are added to foods and cosmetics because of their purported health benefits.[24][25][26]
In a 2004 joint study between the Kuwait Institute for Scientific Research and the Malaysian Palm Oil Board, the scientists found cookies, being higher in fat content than bread, are a better vehicle for red palm oil phytonutrients.[27]
In a 2009 study, scientists in Spain tested the acrolein emission rates from the deep-frying of potatoes in red palm, olive and polyunsaturated oils. They found higher acrolein emission rates from the polyunsaturated oils. The scientists characterized red palm oil as "mono-unsaturated".[28]
Frying French fries in red palm oil gives them an attractive color.[29]
[edit]Refined, bleached, deodorized palm oil
Palm oil products are made using milling and refining processes: first using fractionation, with crystallization and separation processes to obtain solid (stearin), and liquid (olein) fractions. Then melting and degumming removes impurities. Then the oil is filtered and bleached. Next, physical refining removes smells and coloration, to produce "refined bleached deodorized palm oil", or RBDPO, and free sheer fatty acids, which are used as an important raw material in the manufacture of soaps, washing powder and other hygiene and personal care products. RBDPO is the basic oil product sold on the world's commodity markets, although many companies fractionate it further into palm olein, for cooking oil or other products.[30]
Splitting of oils and fats by hydrolysis, or under basic conditions saponification, yields fatty acids, with glycerin (glycerol) as a byproduct. The split-off fatty acids are a mixture ranging in carbon chain length from C4 to C18, depending on the type of oil or fat.[31][32]
[edit]Uses
Derivatives of palmitic acid were used in combination with naphtha during World War II to produce napalm (aluminum naphthenate and aluminum palmitate).[33]
Many processed foods contain palm oil as an ingredient.[18] The highly saturated nature of palm oil, while undesirable from the health perspective, renders it solid at room temperature in temperate regions, making it a cheap substitute for butter in uses where solid fat is desirable, such as the making of pastry dough and baked goods: in this respect, it is less of a health-hazard than the alternative substitute of partially hydrogenated trans fat.
[edit]Biodiesel
Main article: Biodiesel
Palm oil, like other vegetable oils, can be used to create biodiesel, as either a simply processed palm oil mixed with petrodiesel, or processed through transesterification to create a palm oilmethyl ester blend, which meets the international EN 14214 specification. Glycerin is a byproduct of transesterification. The actual process used to produce biodiesel around the world varies between countries and the requirements of different markets. Next-generation biofuel production processes are also being tested in relatively small trial quantities.
The IEA predicts biofuels usage in Asian countries will remain modest. But as a major producer of palm oil, the Malaysian government is encouraging the production of biofuel feedstock and the building of palm oil biodiesel plants. Domestically, Malaysia is preparing to change from diesel to biofuels by 2008, including drafting legislation that will make the switch mandatory.
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