Phenolics and polyphenolic compounds in food and as functional food ingredients: characterization, mechanism(s) of action, structure modification and process effects

流行病学研究表明，食用植物性食物与降低退行性疾病的风险有关，特别是动脉粥样硬化、炎症性疾病和某些类型的癌症。负责这种作用的植物成分由无数种化合物代表，其中一大类是具有抗氧化作用的生物活性酚类和多酚类化合物。因此，必须对这类生物活性物质进行采购和鉴定，并对其性质和生理益处进行检查，以便为其功效提供可信的证据。酚类和多酚类物质促进健康和降低疾病风险的作用机制(S)包括多个复杂的系列事件。因此，清除自由基和活性氧物种，防止低密度脂蛋白(低密度脂蛋白)胆固醇的氧化(心脏病的罪魁祸首)，延缓DNA和突变的分解，导致癌症，以及抑制过量的一氧化氮产生及其有害影响，都需要仔细研究。此外，导致糖尿病、白内障、神经病变等的晚期糖基化终点(AGEs)也是已知的酚类/多酚类物质促进健康的其他机制之一。由于食品是连续消费的，因此，通过不同的加工操作或通过农业实践进行强化，或在食品制备过程中保留或改善吸收和生物利用率，使其富含有益健康的成分，是至关重要的。某些生物活性物质也可被提取并用作营养食品/天然保健品。这项工作将为解开存在的重要酚类和多酚类化合物的身份、它们的含量以及由于加工或修饰以提高活性而引起的变化提供必要的信息。此外，这些生物活性物质的作用机制将被揭开，以填补现有文献中的现有空白。因此，这项工作的结果将提供基本的科学信息，并导致实际应用，这可能有助于通过预防和可能的治疗手段降低保健成本。

Epidemiological studies have demonstrated that the consumption of plant foods is associated with reduced risk of degenerative diseases, particularly atherosclerosis, inflammatory diseases and certain types of cancer. Plant components responsible for such effects are represented by a myriad of compounds, a major class being bioactive phenolics and polyphenolics that render antioxidant effects, among others. Thus, procurement and identification of such bioactives and examination of their properties and physiological benefits must be established in order to provide credible evidence for their efficacy. The mechanism(s) of action of phenolics and polyphenolics in health promotion and disease risk reduction includes a multiple and complex series of events. Thus, scavenging of free radicals and reactive oxygen species, preventing oxidation of low-density lipoprotein (LDL) cholesterol, a culprit in heart disease, retarding breakdown of DNA and mutation, responsible for cancer, and inhibition of excess nitric oxide production with its deleterious effects need to be examined carefully. In addition, advanced glycation endpoints (AGEs) responsible for diabetes, cataract, neuropathy and alike are among the other mechanisms by which phenolics/polyphenolics are known to promote health. Since foods are consumed on a continuous basis, their enrichment with health beneficial components, via different processing operations or enhancement through agricultural practices, or retention during food preparation or improved absorption and bioavailability are of utmost importance. Certain bioactives may also be extracted and used as nutraceuticals/natural health products. This work would provide the necessary information for unraveling the identity of important phenolic and polyphenolic compounds present, their content and changes due to processing or modification for activity enhancement. In addition, mechanisms of actions of such bioactives will be unraveled in order to fill the existing gap in the available literature. Findings of this work would thus provide fundamental scientific information and also leads to practical applications which may contribute to health care cost reduction through preventive and possibly therapeutic means.