Advances in understanding the nutritional value of antioxidants in wheat

Abstract

Whole grain wheat has a diverse supply of hydrophilic and lipophilic antioxidants which include phenolic compounds (phenolic acids, flavonoids, anthocyanins which are present only in pigmented wheat, alkylresorcinols, and to a lesser extent proanthocyanidins), carotenoids (mainly lutein and zeaxanthin) and tocochromanols (α, β, γ and δ - tocopherols and tocotrienols). This diversity of antioxidants function to protect consumers from radical-induced oxidative damage caused by various free radicals produced endogenously from metabolic processes and exogenously from sunlight and other chemicals and environmental pollutants. They also chelate metal ions which could catalyze oxidation reactions in the physiological system, thereby providing antioxidant protection. However, phenolic compounds might exert pro-oxidant effect when bound to heavy metal ions. This effect could be prevented by the diverse antioxidant system in wheat.