cereal ferulate constituents: chemistry and bioavailability as antioxidants

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Canada is not only a world leader in production of grain, but also one of the five major grain exporting countries worldwide. Whole grains hold tremendous potential as healthful food choices. The beneficial effects of whole grain foods in the diet have been largely unrecognized. Only recently has the US Food and Drug Administration allowed a health claim on foods containing at least 51% of ingredients as whole grain. Canada's Food Guide "Eating Well with Canada's Food Guide" recommends increased consumption of whole grains. Scientists have reported reduced cancer and heart disease rates in people with high compared with low whole-grain intakes. The potential biological mechanisms for protection against cancer, cardiovascular disease, diabetes and obesity are diverse since whole grains are rich in nutrients and phytochemicals. A large proportion of phytochemicals is located in bound form to plant cell walls mostly in the outer layers (bran) of the grain. It is my hypothesis that ferulic acid cross-links polysaccharides and lignins in the plant cell walls of a wide range of cereal grains by a strong bond. This bond is pivotal with respect to two major issues associated with phenolics and health - it determines whether phenolics can be extracted or not and it determines the bioefficacy of the ferulic acid since liberation from this bond allows it to counteract the damaging effects of reactive oxygen species via a free radical scavenging mechanism. The antioxidant properties of ferulic acid will depend upon its availability for intestinal absorption and subsequent interaction with target tissues. The guiding principle of the research program is that characterization of the molecular structure - function relationships of grain phytochemicals in raw and processed products can lead to their enhancement as natural antioxidants in multigrain foods where synergistic action will likely result in better health promoting properties.