Normal phase high-performance liquid chromatography method for the determination of tocopherols and tocotrienols in cereals.
The eight vitamers of vitamin E (alpha-, beta-, gamma-, and delta-tocopherols and -tocotrienols) have different antioxidant and biological activities and have different distributions in foods. Some cereals, especially oat, rye, and barley, are good sources of tocotrienols. A fast procedure for the determination of tocopherols and tocotrienols (tocols) in cereal foods was developed. It involves sample saponification and extraction followed by normal phase high-performance liquid chromatography (HPLC). The results have been compared with those found by direct extraction without saponification. The method is sensitive and selective enough to be tested on a wide variety of cereal samples. The highest tocol levels were found in soft wheat and barley ( approximately 75 mg/kg of dry weight). beta-Tocotrienol is the main vitamer found in hulled and dehulled wheats (from 33 to 43 mg/kg of dry weight), gamma-tocopherol predominates in maize (45 mg/kg of dry weight) ), and alpha-tocotrienol predominates in oat and barley (56 and 40 mg/kg of dry weight, respectively).
Panfili
Gianfranco
G
DISTAAM, Università degli Studi del Molise, via De Sanctis, 86100 Campobasso, Italy.
Fratianni
Alessandra
A
Irano
Mario
M
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002523:Edible Grain / Q000737:chemistry*; D024505:Tocopherols / Q000032:analysis*; D024508:Tocotrienols / Q000032:analysis*
D024508:Tocotrienols; D024505:Tocopherols