Enhancement of Bioactivity and Bioaccessibility of Food Phenolics: Structure Modification and Release from Food Matrices

酚类和多酚类化合物是次生代谢物，通过作为抗氧化剂延长植物食品的保质期，保护细胞和身体免受氧化应激的损害，从而影响植物食品的质量。酚类物质产生有益作用的机制各不相同，可能与它们的抗氧化能力无关。一些酚类物质是高度极性的，不溶于非极性介质，如脂肪和油，也不溶于穿过膜双层以中和线粒体中的氧化剂。一般来说，酚类物质以可溶性和结合形式存在；后者不被胃肠道吸收，只在结肠中释放，益处有限，因此在食品加工过程中释放会提高生物可及性和生物活性。这里设定的目标将填补文献中现有的知识空白。因此，通过对酚类化合物的化学结构进行修饰和从两种生物活性分子中制备新化合物，将探索其独特的性质和益处（目标1）。要测试的酚类物质包括白藜芦醇、槲皮素、酪醇、羟基酪醇，可能还有第一次甲基化白藜芦醇的紫檀芪，以及它们与生物活性脂肪酸（如二十二碳六烯酸（DHA））和其他生物分子（如植物甾醇）的脂化作用，并通过化学、仪器、体外和细胞系研究确定它们的活性。最近引入食品科学的一种创新方法（蒸汽爆炸）将用于从细胞壁释放结合的酚类物质，并将结果与使用酶、碱或模拟消化的结果进行比较。试验材料包括种子（扁豆、亚麻荠、索菲亚、奇亚籽）、提取物和可溶性酚提取后的残留物（目的2）。最后，将测试改性酚类物质和获得的可溶和释放结合组分在控制食品系统（如肉类、散装油和水包油乳液）以及低密度脂蛋白胆固醇和DNA模型系统中的氧化作用。此外，将在适当的模型或细胞系系统中检查该制剂的抗炎和其他益处。此外，将探索抑制α-葡萄糖苷酶和α-淀粉酶的活性，阻止葡萄糖的释放，从而使糖尿病患者受益，以及抑制与认知功能/阿尔茨海默病有关的乙酰胆碱酯酶（目的3）。从这些研究中获得的基础知识将推动功能性食品/成分背后的科学，并在食品的设计和配方中扩大新型酚类物质的使用，从而增强对健康的益处，甚至可能是药物。这也将有利于食品技术行业，为消费者生产新的产品，并有利于政府寻求降低医疗保健成本

Phenolic and polyphenolic compounds are secondary metabolites that influence the quality of plant foods by serving as antioxidants to extend their shelf-life and also to protect cells and the body against damage by oxidative stress. The mechanisms for rendering beneficial effects of phenolics vary and may be independent from their antioxidant potential. Some phenolics are highly polar and insoluble in non-polar media such as fats and oils and also in crossing membrane bilayers to neutralize oxidants in the mitochondria. Generally, phenolics exist in the soluble and bound forms; the latter are not absorbed in the gastrointestinal tract and are only released in the colon, with limited benefits, thus their release during food processing would improve bioaccessibility and bioactivity. The goals set here will fill the existing knowledge gap in the literature. Therefore, unique properties and benefits, upon modification of chemical structures of phenolics and preparation of novel compounds from two bioactive molecules will be explored (OBJECTIVE 1). The phenolics to be tested include resveratrol, quercetin, tyrosol, hydroxytyrosol, and possibly pterostilbene, a methylated resveratrol, for the first time, and their lipophilization with bioactive fatty acids such as docosahexaenoic acid (DHA), and others or biomolecules like phytosterols and determination of their activities using chemical, instrumental, in-vitro and cell-line studies. An innovative method (steam explosion) that has recently been introduced to food science will be used to release bound phenolics from cell walls and compare the results with those from using enzymes, base or simulated digestion for their release. The test materials include seeds (lentils, camelina, sophia, chia), extracts and residues after extraction of soluble phenolics (OBJECTIVE 2). Finally, modified phenolics and those procured, both soluble and released bound fractions, will be tested for their efficacy in controlling oxidation in food systems such as meat, bulk oil and oil-in-water emulsion as well as in model systems of LDL cholesterol and DNA. In addition, anti-inflammatory and other benefits of the preparations will be examined in appropriate model- or cell-line systems. Further, inhibition of activities of α-glucosidase and α-amylase that deter the release of glucose and hence benefit diabetics as well as inhibition of acetyl cholinesterase, involved in cognitive function/Alzheimer's disease, will be explored (OBJECTIVE 3). The fundamental knowledge gained from these studies would advance the science behind functional foods/ingredients, and expand the use of novel phenolics in the design and formulation of foods with enhance benefits to health, and possibly pharmaceuticals. It would also be of benefit to the food technology industry, producing novel products for consumer benefit, and to government seeking to reduce health care costs.**