Antioxidant properties of diverse cereal grains: A review on in vitro and in vivo studies

• In vitro and in vivo antioxidant activities of cereal grains are summarized.
• Cereals provide significant levels of bioactive phytochemicals including phenolic acids and carotenoids.
• These phytochemicals are unevenly distributed in the grain kernel and possess antioxidant properties.
• Consumption of cereal grain products favorably alters endogenous antioxidant markers.
• Adequate intake of cereal grains may potentially mitigate oxidative stress.

Cereal grains and products have gained popularity in contributing to healthy eating behavior because of their antioxidant properties associated with protection against chronic diseases. In this review, notable studies on the in vitro and in vivo antioxidant activity of commonly consumed cereal grains are summarized. Cereals contain phytochemicals or certain minor components with antioxidant properties. The antioxidant potential of cereals depends on their bioaccessibility, absorption in the gastrointestinal and their bioavailability utilization in vivo. The in vitro gastrointestinal digestion and fermentation of cereals increased their antioxidant potentials which are significantly correlated with their total phenolic contents. Most studies performed in vivo have been concerned with the antioxidant properties of colored rice, wheat bran and rye products. There are inadequate in vitro and in vivo studies on antioxidative potentials of fermented versus unfermented cereals. Therefore, further studies are necessary to maximize possible health benefits of cereal antioxidative phytochemicals.