Tocopherols vitamin food sources

It is fortuitous that indigenous concentrations of vitamin E in the principal food sources are on the order of mg rather than yug/100 g, for the tocopherols and tocotrienols exhibit relatively low intensities of UV absorption. Individual vitamers are characterized by a slightly different absorption maximum within the wavelength range of 292-298 nm in ethanol. Published A] m values for the tocopherols at their Amax in ethanol are a-T 70-73.7 at 292 nm, (3-T 86-87 at 297 nm, y-T 90-93 at 298 nm, and <5-T 91.2 at 298 nm (126). The different absorption characteristics among the vitamers necessitates the running of individual standards for accurate quantitation of each vitamer. The absorption intensity of a-tocopheryl acetate is lower still with an A j m value of only 40-44 at the Amax of 285.5 nm (44). Reported minimum detectable quantities of a-, / -, y-, and (5-tocopherols at 295 nm are, respectively, 50 ng, 70 ng, 90 ng, and 130 ng (127). 

The application of semi-synthetic (R,R,R)-a-tocopherol from natural sources is exclusively restricted to the pharmaceutical, food, and cosmetic industry. The most important natural sources of vitamin E are plant oil and fats. Various processes... 

The best food sources of vitamin E are vegetable oils, green leafy vegetables, whole grains, seeds and nuts. Almonds and hazelnuts contain 8.S-9.5 a-tocopherol equivalents per 40g serving, for an impressive 100% of the FDA s proposed reference daily intake (formerly US RDA). 

Vitamin requirements are mainly fulfilled by plant lipids, especially oils, and in some countries by margarine enriched with tocopherols. Other foods of both plant and animal origin are also important additional sources. Although they contain fewer vitamins, they are consumed regularly and in high quantities (e.g. bakery products, meat, eggs and some vegetables). 

For additional sources and more precise values of vitamin E (alpha-tocopherol), see Food Composition Table F-21. 

The main sources of these compounds are vegetable oils, unprocessed cereal grains, and nuts. The vitamin formulations that may be added to foods are o-a-tocopherol, OL-a-tocopherol, o-a-tocopheryl acetate, oL-a-tocopheryl acetate, and o-a-tocopheryl acid succinate [403],... 

The supply of palm oil has risen considerably since around 1980. It was almost 24 million tons per annum in 2001-2002 and is predicted to exceed the production of soybean oil during the period 2011-2015 at around 37 milhon tons. The oil contains almost equal proportions of saturated (palmitic 48% and stearic 4%) and unsaturated acids (oleic 37% and hnoleic 10%). The major triacylglycerols are POP (30-40%) and POO (20-30%). The oil is used mainly for food purposes but finds some nonfood uses. It is a source of valuable byproducts such as carotene and tocopherols and tocotrienols (vitamin E). Red palm oil is a carefully prepared oil that retains about 80% (500-700 ppm) of the carotenes present in the crude oil and is a valuable dietary source of these important compounds (42). 

Soybean tocopherols are the major source of natural fat-soluble antioxidants and Vitamin E. The Vitamin E activity of natural d-cx-tocopherol is much greater that that of synthetic Vitamin E, which is a mixture of eight stereoisomers (203). Phytosterols are used as raw materials for over 75% of the world s steroid production. The more recent application of phytosterol, phytostanol, and their fatty acid esters in margarine and table spreads is based on the blood cholesterol-lowering effect of these compounds (204,205). The recent development of functional foods containing phytosterols has been reviewed by Hollingsworth (206) and Hicks and Moreau (207). 

Good sources of vitamin E are vegetable oils, such as com, soy, and peanut oii. Animal fats, such as butter and lard, contain lowrer amounts of the vitamin. The content of the most important form of vitamin E, a-tocopherol, in various foods is as follows. Com oil contains about 16 mg of a-tocopherol per 100 g sunflower oil 50 mg/100 g, wheat germ oil 120 mg/100 g and fish, eggs, and beef 0.5 to 2,0 rng/100 g. In plants, a-tocopherol resides in chloroplasts, while other forms of tocopherol ( i-, y-, and 5-tocopherol) occur elsewhere in the plant cell. Tocotrienols, which also have vitamin E activity, are not found in the green parts of plants, but in the bran and germ of seeds... 

Plant lipids increase the nutritional value of food they contain more essential FA than animal fats. They also contain tocopherols and tocotrienols, which are the most important sources of vitamin E. A disadvantage is that plant lipids (similar to animal fats) considerably increase the content of available energy. Therefore, the consumption of fried foods should be restricted because they are rich in fat. 

Refined palm oil contains approximately 500 to 700ppm vitamin E, which is present as the RRR-a-tocopherol (30%) and tocotrienol (70%) isomers. In contrast, oils such as com, soybean, and sunflower are good sources of the tocopherols but contain no tocotrienols. Historically, vitamin E activity (one international unit, lU) has been defined as 1 mg of all rac-a-tocopheiyl acetate, whereas Img of all RRR-a-tocopherol equals 1.49 lU. In addition, vitamin E activity in foods is expressed as the a-tocopherol equivalent (a-TE), which is the activity of 1 mg of RRR-a-tocopherol. On this basis, conversion factors for each milligram of the different tocopherols and tocotrienols present in palm oil to a-TE have been calculated as follows a-tocopherol, 1.0 y-tocopherol, 0.5 5-tocopherol, 0.1 a-tocotrienol, 0.3 and P-tocotrienol, 0.05. The factors for y- and 5-tocotrienol are presently unknown." The conversion factors are based on the ability of each isomer to overcome specific vitamin E deficiency symptoms such as fetal resorption, muscular dystrophy, and encephalomalacia. Since these factors are based on rat fetal resorption assays, their relevance to humans... 

Vitamin E (alpha-tocopherol) has been the subject of several cancer prevention and immune function studies because of its ability to neutralize free radicals, but results have been mixed. If you use diet to boost vitamin E, it is important to balance how much you consume of some of its richest sources since many are high-fat foods. Avocado, olive oil, canola oil, almonds, and hazelnuts are examples. 

Vitamin E, also called tocopherol, is a lipid-soluble antioxidant. Within animal tissues, it is located in the plasmalemma and subcellular membranes. Muscle foods are generally a poor source of vitamin E (Piironen et al., 1985) while nuts, cereal grains and plant oils contain significant quantities of this nutrient (Harris et al., 1950). 

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