Vitamin E isomers in grain amaranths ( Amaranthus spp.)

Vitamin E isomers are important antioxidants, but their variation is poorly documented in pseduocereal grains such as amaranths. Using normal‐phase, high‐performance liquid chromatography with fluorescence detection, seeds of thirteen amaranth ( Amaranthus cruentus L., A. hypochondriacus L.) accessions were surveyed for the composition of tocols. The most common tocols found were α‐tocopherol (2.97 to 15.65 mg/kg seed) and β‐tocotrienol (5.92 to 11.47 mg/kg seed) and γ‐tocotrienol (0.95 to 8.69 mg/kg seed), while some A. cruentus accessions contained δ‐tocotrienol (0.01 to 0.42 mg/kg seed). This is the first report of tocotrienols in amaranths. Amaranthus cruentus grain‐types of Mesoamerican origin had significantly ( P ≤0.01) greater levels of four tocols than did A. cruentus African vegetable‐types. Unlike many cereal grains, amaranths have significant amounts of both β‐ and γ‐tocotrienols; however, β‐tocopherol was not detected in any of the amaranths. Using multiple linear regressions, α‐tocopherol variation of both species and types was consistently explained by variation in tocols other than α‐tocopherol. On the whole, fresh amaranth samples of both species tended to have higher levels of tocotrienols than samples stored for two years. Storage effects on amaranth tocol composition are suspected.