There are three methods for extracting
vegetable oils from
plants. The relevant part of the plant may be placed under
pressure to "extract" the
oil, giving an
expressed oil. Oils may also be extracted from plants by
dissolving parts of plants in water or another
solvent. The solution may be separated from the plant material and concentrated, giving an extracted or
leached oil. The mixture may also be separated by
distilling the oil away from the plant material. Oils extracted by this latter method are called
essential oils. Essential oils often have different properties and uses than
pressed or
leached vegetable oils.
Macerated oils are made by infusing parts of plants in a base oil a process known as
maceration.
Although most plants contain some oil, only the oil from certain major oil crops
[1] complemented by a few dozen minor oil crops
[2] is widely used and traded. These oils are one of several
types of plant oils.
Vegetable oils can be classified in several ways, for example:
- By source: most, but not all vegetable oils are extracted from the fruits or seeds of plants, and the oils may be classified by grouping oils from similar plants, such as "nut oils".
- By use: oils from plants are used in cooking, for fuel, for cosmetics, for medical purposes, and for other industrial purposes.
The vegetable oils are grouped below in common classes of use.
[edit] Edible oils
[edit] Major oils
These oils account for a significant fraction of worldwide edible oil production. All are also used as
fuel oils.
- Coconut oil, a cooking oil, high in saturated fat, particularly used in baking and cosmetics.[3]
- Corn oil, a common cooking oil with little odor or taste.[4]
- Cottonseed oil, used in manufacturing potato chips and other snack foods.[5]
- Olive oil, used in cooking, cosmetics, soaps, and as a fuel for traditional oil lamps.[6]
- Palm oil, the most widely produced tropical oil. Popular in West African and Brazilian cuisine.[7] Also used to make biofuel.[8]
- Peanut oil (Ground nut oil), a clear oil used for dressing salads and, due to its high smoke point, especially used for frying.[9]
- Rapeseed oil, including Canola oil, one of the most widely used cooking oils.[10]
- Safflower oil, produced for export for over 50 years, first for use in paint industry, now mostly as a cooking oil.[11]
- Sesame oil, cold pressed as light cooking oil, hot pressed for a darker and stronger flavor.[12]
- Soybean oil, produced as a byproduct of processing soy meal.[13]
- Sunflower oil, a common cooking oil, also used to make biodiesel.[14]
[edit] Nut oils
Nut oils are generally used in cooking, for their
flavor. Most are quite costly, because of the difficulty of extracting the oil.
- Almond oil, used as an edible oil, but primarily in the manufacture of pharmaceutical drugs.[15]
- Cashew oil, somewhat comparable to olive oil. May have value for fighting dental cavities.[16]
- Hazelnut oil, mainly used for its flavor. Also used in skin care, because of its slight astringent nature.[17][18]
- Macadamia oil, strongly flavored, contains no trans fat.
- Mongongo nut oil (or manketti oil), from the seeds of the Schinziophyton rautanenii, a tree which grows in South Africa. High in vitamin E. Also used in skin care.[19]
- Pracaxi oil, from the seeds of the Pentaclethra macroloba, or Oil Tree, which is native to the wet tropical areas around the north eastern part of South America. Has one of the highest level of behenic acid among natural products.
- Pecan oil, valued as a food oil, but requiring fresh pecans for good quality oil.[20]
- Pine nut oil added to foods usually as a flavoring agent.
- Pistachio oil, strongly flavored oil, particularly for use in salads.[21]
- Sacha Inchi (Plukenetia volubilis) oil, contains no cholesterol and the highest omega-3 fatty acid concentration (~ 49%)
- Walnut oil, used for its flavor, also used by Renaissance painters in oil paints.[22][23]
[edit] Oils from melon and gourd seeds
Members of the
cucurbitaceae include
gourds,
melons,
pumpkins, and
squashes. Seeds from these plants are noted for their oil content, but little information is available on methods of extracting the oil. In most cases, the plants are grown as food, with dietary use of the oils as a byproduct of using the seeds as food.
[24]
- Bottle gourd oil, extracted from the seeds of the Lagenaria siceraria, widely grown in tropical regions. Used medicinally and as an edible oil.[25]
- Buffalo gourd oil, from the seeds of the Cucurbita foetidissima, a vine with a rank odor, native to southwest North America.[26]
- Butternut squash seed oil, from the seeds of Cucurbita moschata, has a nutty flavor that is used for salad dressings, marinades, and sautéing'[27]
- Pumpkin seed oil, a specialty cooking oil, produced in Austria, Slovenia and Croatia. Used mostly in salad dressings. Poor tolerance for high temperatures.[28]
- Watermelon seed oil, pressed from the seeds of Citrullus vulgaris. Traditionally used in cooking in West Africa.[29]
[edit] Food supplements
A number of oils are used as
food supplements, for their nutrient content or medical effect.
[edit] Other edible oils
- Amaranth oil, high in squalene and unsaturated fatty acids, used in food and cosmetic industries.[34]
- Apricot oil, similar to, but much cheaper than almond oil, which it resembles. Only obtained from certain cultivars.[35]
- Apple seed oil, used in cosmetics and shampoos.[36] Also used as an edible oil.[37]
- Argan oil, a food oil from Morocco that has also attracted recent attention in Europe.[38]
- Artichoke oil, extracted from the seeds of the Cynara cardunculus. Similar in use and composition to safflower and sunflower oil.[39]
- Avocado oil, a nutty-flavored culinary oil, also used as a base for infusions.[40] Also used in cosmetics.[41] Unusually high smoke point of 510°F.[42]
- Babassu oil, similar to, and used as a substitute for, coconut oil.[43]
- Ben oil, extracted from the seeds of the Moringa oleifera. High in behenic acid. Extremely stable edible oil. Also suitable for biofuel.[44]
- Borneo tallow nut oil, extracted from the fruit of species of genus Shorea. Used as a substitute for cocoa butter, and to make soap, candles, cosmetics and medicines.[45]
- Cape Chestnut oil, otherwise known as Yangu oil, is a popular oil in African skin care.
- Carob pod oil (Algaroba oil), from carob, used medicinally.[46]
- Cassia oil, made from Cinnamon, this spiced oil is used to flavour Easter biscuits
- Cocoa butter, from the cacao plant. Used in the manufacture of chocolate, as well as in some cosmetics.
- Cocklebur oil, from species of genus Xanthium, with similar properties to poppyseed oil, similar in taste and smell to sunflower oil.[47][48]
- Cohune oil, from the Attalea cohune (cohune palm), similar to coconut oil in makeup and usage[49]
- Coriander seed oil, from coriander seeds, used medicinally. Also used as a flavoring agent in pharmaceutical and food industries.[50]
- Dika oil, from Irvingia gabonensis seeds, native to West Africa. Used to make margarine, soap and pharmaceuticals, where is it being examined as a tablet lubricant. Largely underdeveloped.[51][52]
- False flax oil made of the seeds of Camelina sativa, available in Russia as ryjhikovoye maslo (рыжиковое масло). Considered promising as a food or fuel oil.[53]
- Flax seed oil (called linseed oil when used as a drying oil). High in omega 3 and lignans, which can be used medicinally. Easily turns rancid.[54]
- Grape seed oil, suitable for cooking at high temperatures. Also used as a salad oil, and in cosmetics.[55]
- Hemp oil, a high quality food oil.[56]
- Kapok seed oil, used as an edible oil, and in soap production.[57]
- Kenaf Seed oil a fibre plant similar to Hemp.
- Lallemantia oil, from the seeds of Lallemantia iberica, discovered at archaeological sites in northern Greece.[58]
- Marula oil, extracted from the kernel of Sclerocarya birrea. Used in the food and cosmetic industry, it has strong antioxidant and moisturising properties.[59]
- Meadowfoam seed oil, highly stable oil, with over 98% long-chain fatty acids. Competes with rapeseed oil for industrial applications.[60]
- Mustard oil (pressed), used in India as a cooking oil. Also used as a massage oil.[61]
- Nutmeg butter, extracted by expression from the fruit of cogeners of genus Myristica. Nutmeg butter has a large amount of trimyristin. Nutmeg oil, by contrast, is an essential oil, extracted by steam distillation.[62]
- Okra seed oil, from Abelmoschus esculentus. Composed predominantly of oleic and linoleic acids.[63] The greenish yellow edible oil has a pleasant taste and odor.[64]
- Papaya seed oil, high in omega-3 and omega-6. Used as skin treatment. Similar to olive oil, with a sweet flavor.[65]
- Perilla seed oil, high in omega-3 fatty acids. Used as an edible oil, for medicinal purposes, in skin care products and as a drying oil.[66]
- Pequi oil, extracted from the seeds of Caryocar brasiliense. Used in Brazil as a highly prized cooking oil.[67]
- Pine nut oil. An expensive food oil, from pine nuts, used in salads and as a condiment.[68]
- Poppyseed oil, used for cooking,[69] moisturizing skin,[70] in paints and varnishes,[71] and in soaps.
- Prune kernel oil, marketed as a gourmet cooking oil.[72]
- Quinoa oil, similar in composition and use to corn oil.[73]
- Ramtil oil, pressed from the seeds of the one of several species of genus Guizotia abyssinica (Niger pea) in India and Ethiopia. Used for both cooking and lighting.[74]
- Rice bran oil, suitable for high temperature cooking. Widely used in Asia.[75]
- Royle oil, pressed from the seeds of Prinsepia utilis, a wild, edible oil shrub that grows in the higher Himalayas. Used medicinally in Nepal.[76]
- Sacha Inchi oil, from the Peruvian Amazon. High in omega-3 and omega-6 fatty acids.[77]
- Tea seed oil (Camellia oil), widely used in southern China as a cooking oil. Also used in making soaps, hair oils and a variety of other products.[78]
- Thistle oil, pressed from the seeds of Silybum marianum. Relatively unstable. Also used for skin care products.[79]
- Tigernut oil (or nut-sedge oil) is pressed from the tuber of Cyperus esculentus. It has properties similar to soybean, sunflower and rapeseed oils.[80] It is used in cooking and making soap[81] and has potential as a biodiesel fuel.[80]
- Tomato seed oil. High in unsaturated fats and lysine. Potentially useful as a protein supplement.[82]
- Wheat germ oil, used as a dietary supplement, and for its "grainy" flavor. Also used medicinally. Highly unstable.[83]
