Characterization of polyphenol-protein reactions in model systems and foods

酚类化合物是植物源性食品中的质量决定化合物，由于其对人类健康的有益作用而被广泛用作功能性食品成分。为此，它们从各种来源提取，如茶叶，葡萄皮和种子，苹果，甚至药用植物。由于失去了天然的保护基质，酚类化合物在加工过程中暴露于氧气，因此可能被氧化成不稳定的活性中间体。这些所谓的醌可以与许多食物成分相互作用，特别是与蛋白质。这种反应的技术和生物化学后果是多方面的，例如蛋白质的交联、酶活性的变化、氨基酸和酚类的生物利用度降低以及食物蛋白质的免疫学特性的改变。虽然该项目的主要目的是使用高度复杂的分析技术表征酚类化合物和蛋白质反应形成的产品，但更好地了解酚类化合物的稳定性及其与其他食品成分的相互作用将有助于得出优化工艺的结论生产这将有助于评估（功能性）食品的安全性，并在一定程度上允许评估潜在的不利影响。鉴于功能性食品在整个食品市场中的重要性日益增加，对其生物活性成分的反应性进行研究是必不可少的。了解蛋白质与酚类物质反应后发生的变化也可能导致低过敏性食品的生产。因此，预计拟议调查的结果将刺激跨学科研究，特别是在食品化学和食品技术，营养科学，毒理学和免疫学领域。

Phenolic compounds are quality determining compounds in plant-derived foods and are widely used as functional food ingredients, owing to their supposed beneficial effects on human health. For this purpose they are extracted from various sources such as tea leaves, grape skins and seeds, apples, and even medicinal plants. Being deprived of their natural protecting matrices, the phenolics are exposed to oxygen during processing and may therefore be oxidized to instable, reactive intermediates. These so-called quinones can interact with a number of food constituents, in particular with proteins. The technological and biochemical consequences of such reactions are manifold, e.g. crosslinking of proteins, changes in enzyme activities, reduced bioavailability of both amino acids and phenolics, and modifications of the immunological properties of food proteins. While it is the primary aim of this project to characterize the products formed by the reaction of phenolic compounds and proteins using highly sophisticated analytical techniques, a better understanding of the stability of phenolic compounds and their interactions with other food constituents would allow conclusions on the optimization of processes for the production of (functional) foods and would also, to a certain extent, allow the estimation of potential adverse effects. In view of the growing importance of functional foods within the overall food market, investigations into the reactivity of their bioactive constituents are essential. Knowledge of the alterations of proteins by reaction with phenolics may also lead to the production of hypoallergenic food. Thus, it is anticipated that the results of the proposed investigations will stimulate cross-disciplinary research, in particular in the fields of food chemistry and food technology, nutritional science, toxicology, and immunology.