Coelho Carina, Ribeiro Miguel, Cruz Ana C S, Domingues M Rosário M, Coimbra Manuel A, Bunzel Mirko, Nunes Fernando M
CQ-VR, Chemistry Research Centre, Department of Chemistry, Universidade de Trás-os-Montes e Alto Douro , 5000-801 Vila Real, Portugal.
J Agric Food Chem. 2014 Aug 6;62(31):7843-53. doi: 10.1021/jf501510d. Epub 2014 Jul 23.
Phenolic compounds are incorporated into coffee melanoidins during roasting mainly in condensed form (42-62 mmol/100 g) and also in ester-linked form (1.1-1.6 mmol/100 g), with incorporation levels depending on the green coffee chlorogenic acid content. The phenolic compounds are incorporated in different coffee melanoidin populations, but mainly in those soluble in 75% ethanol (82%), a significant correlation between the amount of phenolic compounds and the amount of protein and color characteristics of the different melanoidin populations being observed. The incorporation of phenolic compounds into coffee melanoidins is a significant pathway of chlorogenic acid degradation during roasting, representing 23% of the chlorogenic acids lost. These account for the nearly 26% of the material not accounted for by polysaccharides and proteins present in coffee melanodins. The cleavage mechanism and the efficiency of alkaline fusion used to release condensed phenolics from coffee melanoidins suggest that the phenolic compounds can be linked to the polymeric material by aryl-ether, stilbene type, and/or biphenyl linkages.
在烘焙过程中，酚类化合物主要以缩合形式（42 - 62 mmol/100 g）和酯键连接形式（1.1 - 1.6 mmol/100 g）掺入咖啡黑素中，掺入水平取决于生咖啡豆绿原酸的含量。酚类化合物掺入不同的咖啡黑素群体中，但主要掺入那些可溶于75%乙醇的群体中（82%），观察到酚类化合物的量与不同黑素群体的蛋白质含量和颜色特征之间存在显著相关性。酚类化合物掺入咖啡黑素中是烘焙过程中绿原酸降解的一条重要途径，占损失的绿原酸的23%。这些酚类化合物约占咖啡黑素中未被多糖和蛋白质解释的物质的26%。用于从咖啡黑素中释放缩合酚类的碱熔裂解机制和效率表明，酚类化合物可通过芳基醚、二苯乙烯型和/或联苯键与聚合材料相连。
