Structure-function properties of oat protein-derived antioxidant peptides

在接触氧化食物、有毒物质或感染病原体的过程中，人体内会产生过量的不健康物质，即氧和氮衍生自由基物种。这是由于人体抗氧化防御系统和体内产生的氧化剂(如自由基)之间的失衡造成的。这种失衡与包括癌症、心血管疾病和老年性黄斑变性在内的几种慢性人类疾病的病因学有关。流行病学研究清楚地表明，像谷类这样的食物的消费与其中一些疾病的发病率下降有关。然而，对观察到的影响负有责任的食品成分的性质及其作用机制还没有很好的定义。本研究的目的是鉴定谷物中的生物活性多肽，并在细胞水平上确定它们的作用机制，以阐明其在疾病预防中的活性成分。燕麦种子用于提取纤维(如β-葡聚糖)的利用率增加，留下了高蛋白残留物(重量50%)，这些残留物将被用作生物活性多肽的来源，以减少氧化应激，进而改善加拿大人的健康。该方法将涉及1)燕麦蛋白提取和酶消化的优化；2)多肽的分离(按电荷和大小)和鉴定；3)多肽的抗氧化测试和结构功能关系。这一结果将有助于更好地理解多肽抗氧化剂在调节/预防人类慢性疾病中的作用。在食品系统中使用多肽作为抗氧化物质的优势包括其额外的营养功能。这项工作将阐明氨基酸基团和多肽功能之间的关系，并可能导致更有效的功能食品和营养食品的开发，从而提高燕麦种子的附加值利用，为加拿大经济带来显著的经济效益。

There is an overproduction of unhealthy substances in the human body known as oxygen- and nitrogen-derived radical species during exposure to oxidized foods, toxic substances, or infection with a pathogen. This occurs as a result of an imbalance between the human antioxidant defense system and oxidants (e.g. free radicals) produced in the body. This imbalance is involved in the etiology of several chronic human diseases including cancer, cardiovascular diseases and age-related macular degeneration. Epidemiological studies have clearly demonstrated that the consumption of foods like cereals, is correlated with a decreased incidence of some of these diseases. However, the nature of food ingredients responsible for the observed effects and their mechanisms of action are not well defined. The aim of this research is to identify bioactive peptides in grains and determine their mechanism of action at the cellular level in order to elucidate the active elements in disease prevention. Increased utilization of oat seeds for fibre (e.g. beta-glucans) extraction leaves behind a high protein residue (>50% by weight) that will be used as sources of bioactive peptides to reduce oxidative stress and then improve Canadians' health. The approach will involve 1) optimization of oat proteins extraction and enzymatic digestion; 2) separations (by charge and size) and identification of peptides; and 3) antioxidant testing of peptides and structure function relationships. The results will lead to a better understanding of the role of peptide antioxidants in the regulation/prevention of chronic human diseases. Advantages of using peptides as antioxidant substances in food systems include their additional nutritional functions. This work will elucidate relationships between amino acid groups and peptide functionality, and could lead to the development of more effective functional foods and nutraceuticals that will enhance value-added utilization of oat seeds with significant economic benefits to the Canadian economy.