CoulArray electrochemical evaluation of tocopherol and tocotrienol isomers in barley, oat and spelt grains

Hexane extracts obtained from Hordeum vulgare L. (barley), Avena sativa L. (oat), Triticum spelta Schrank and Triticum dicoccum Schrank ex Schübler (spelt or emmer) whole grains, were examined for their tocochromanol (tocopherol and tocotrienol) content. The analyses were carried out on fatty extracts by means of HPLC coupled with a coulometric array electrochemical detector (ECD). Due to the specific high selectivity of the detector, the sample can be directly injected without any preliminary treatment (e.g., saponification). Eight tocochromanol isomers have been detected in barley grains. Different barley cultivars examined showed a tocochromanol content ranging from 1620 to 1852 ng/g caryopses. Oat grains contained ca. 45 ng/g caryopses and Triticum species ca.1070 ng/g caryopses. The results are considered in view of a potential use of vitamin E derivatives as human health enhancer and as sources of antioxidants for food lipid preservation.