Vitamin E Homologs and γ-Oryzanol Levels in Rice (Oryza sativa L.) During Seed Development

Vitamin E homologs (tocopherols and tocotrienols) and gamma-oryzanol have gained significant attention because of their proposed health benefits and ability to increase vegetable oil stability. Changes in the levels of these phytochemicals were examined during seed development. Rapid accumulation of tocopherols, tocotrienols, and gamma-oryzanol occurred during early seed development. During the middle stage of seed development, the levels of tocopherols decreased sharply, and the levels of tocotrienols either stayed the same or decreased slightly, whereas gamma-oryzanol continued to accumulate until maturity. The levels of these compounds remained constant from maturity to 15 days postmaturity. In conclusion, rice grain for nutraceutical and functional food applications should be harvested during its immature stage to obtain the highest amount of tocopherols, whereas the amounts of the other phytochemicals that were studied can be optimized by harvesting grain at maturity.