cereal ferulate constituents: chemistry and bioavailability as antioxidants

加拿大不仅是世界粮食生产大国，也是世界五大粮食出口国之一。全谷物作为健康食品的选择有着巨大的潜力。全谷物食品在饮食中的有益作用在很大程度上未被认识到。直到最近，美国食品和药物管理局才允许对含有至少51%全谷物成分的食品进行健康声明。加拿大的食物指南“吃得好与加拿大的食物指南”建议增加全谷物的消费。科学家们报告说，与低摄入量的人相比，高摄入量的人患癌症和心脏病的几率更低。由于全谷物富含营养和植物化学物质，因此预防癌症、心血管疾病、糖尿病和肥胖的潜在生物学机制多种多样。大部分植物化学物质以结合形式存在于植物细胞壁上，主要存在于谷物的外层（麸皮）中。这是我的假设，阿魏酸交联多糖和木质素在植物细胞壁的广泛谷类谷物通过一个强键。这一键在与酚类物质和健康相关的两个主要问题上至关重要——它决定了酚类物质能否被提取，它决定了阿魏酸的生物功效，因为从这一键中解放出来，阿魏酸可以通过自由基清除机制抵消活性氧的破坏性影响。阿魏酸的抗氧化性能将取决于其肠道吸收的有效性以及随后与靶组织的相互作用。该研究计划的指导原则是，在原料和加工产品中表征谷物植物化学物质的分子结构-功能关系，可以导致它们作为天然抗氧化剂在杂粮食品中的增强，其中协同作用可能会产生更好的健康促进特性。

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.