Department of Metabolism and Nutrition, Institute of Food Science, Technology and Nutrition (ICTAN-CSIC). Spanish National Research Council (CSIC), José Antonio Novais 10, 28040 Madrid, Spain.
Food Funct. 2018 Jan 24;9(1):331-343. doi: 10.1039/c7fo01553d.
Roasting greatly reduces the phenolic content in green coffee beans. Considering the beneficial effects of coffee polyphenols, blends containing green coffee beans are being consumed as a healthier alternative to roasted coffee. This study was aimed at assessing the absorption and metabolism of hydroxycinnamates in an instant green/roasted (35/65) coffee blend in healthy humans. Twelve fasting men and women consumed a cup of coffee containing 269.5 mg (760.6 μmol) of chlorogenic acids. Blood and urine samples were taken before and after coffee consumption at different times and analyzed by LC-MS-QToF. Up to 25 and 42 metabolites were identified in plasma and urine, respectively, mainly in the form of sulfate and methyl derivatives, and to a lower extent as glucuronides. Un-metabolized hydroxycinnamate esters (caffeoyl-, feruloyl-, and coumaroylquinic acids), hydroxycinnamic acids (caffeic, ferulic and coumaric acids) and their phase II metabolites, in addition to phase II derivatives of lactones, represented a minor group of metabolites (16.3% of the metabolites excreted in urine) with kinetics compatible with small intestine absorption. Dihydrohydroxycinnamic acids and their phase II derivatives, in addition to feruloylglycine, showed delayed kinetics due to their colonic origin and represented the most abundant group of metabolites (75.7% of total urinary metabolites). Dihydrohydroxycinnamate esters (dihydroferuloyl-, dihydrocaffeoyl- and dihydrocoumaroylquinic acids) have been identified for the first time in both plasma and urine, with microbial origin (excreted 8-12 h after coffee intake) amounting to 8% of total urinary metabolites. In conclusion, coffee polyphenols are partially bioavailable and extensively metabolized, mainly by the colonic microbiota.
烘焙会大大降低绿咖啡豆中的酚类含量。考虑到咖啡多酚的有益作用，含有绿咖啡豆的混合物作为烤咖啡的更健康替代品正在被消费。本研究旨在评估瞬时绿/烤（35/65）咖啡混合物中羟基肉桂酸在健康人体中的吸收和代谢。12 名空腹男性和女性饮用了一杯含有 269.5 毫克（760.6 微摩尔）绿原酸的咖啡。在不同时间点，在饮用咖啡前后采集血液和尿液样本，并通过 LC-MS-QToF 进行分析。在血浆和尿液中分别鉴定出多达 25 和 42 种代谢物，主要以硫酸盐和甲基衍生物的形式存在，其次是低程度的葡萄糖醛酸苷。未代谢的羟基肉桂酸酯（咖啡酰、阿魏酰和香豆酰奎宁酸）、羟基肉桂酸（咖啡酸、阿魏酸和香豆酸）及其 II 相代谢物，以及内酯的 II 相衍生物，构成了代谢物的一小部分（尿液中排泄的代谢物的 16.3%），其动力学与小肠吸收一致。由于其来源于结肠，二羟基肉桂酸及其 II 相衍生物以及阿魏酰甘氨酸的动力学延迟，代表了最丰富的代谢物组（总尿代谢物的 75.7%）。二羟基肉桂酸酯（二羟基阿魏酰、二羟基咖啡酰和二羟基香豆酰奎宁酸）首次在血浆和尿液中被鉴定出来，其微生物来源（在咖啡摄入后 8-12 小时排泄）占总尿代谢物的 8%。总之，咖啡多酚部分具有生物利用度，并广泛代谢，主要由结肠微生物群代谢。
