Normal Phase High-Performance Liquid Chromatography Method for the Determination of Tocopherols and Tocotrienols in Cereals

Abstract

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).

Influence of mevinolin on chloroplast terpenoids in Cannabis sativa

“…Tocopherols were extracted as described for cereal seeds by Panfili et al (2003), by grinding and homogenizing 25 mg of freeze-dried leaf material in 500 ml 100 % methanol. After 20 min of incubation at 30°C, the samples were centrifuged at 14,000 rpm for 5 min, the supernatant was transferred to new tubes, and the pellet was re-extracted twice with 250-μl 100 % methanol at 30°C for 30 min, pooling all supernatants.…”

Dietary xylanase increases hepatic vitamin E concentration of chickens fed wheat based diet

“…It has also been suggested that xylanase in poultry diets improves gut health as indicated by reduced endogenous losses from the gastrointestinal tract (Bedford and Schulze, 1998). Wheat also contains about 75 mg of vitamin E (Panfili et al, 2003) and 2 mg of carotenoids (Hidalgo et al, 2006) per kg dry matter, which may contribute ABSTRACT. The study examined the effect of xylanase supplementation on apparent metabolizable energy (AME) and hepatic vitamin E and carotenoids in broiler chickens fed wheat based diets.…”

Liposoluble Antioxidative Components in Japanese Traditional Fermented Food "Amazake" Made from Brown Rice

“…Extraction from each food sample was performed according to a previous procedure [17] with a small modification. Wet food sample (5.00 g), NaCl solution (1.80 mL, 10 g/L water), pyrogallol solution (200 μL, 6 g/L ethanol), and ethyl acetate (3.00 mL) were mixed in a 15-mL centrifuge tube and shaken vigorously.…”