Grape and pomegranate are rich sources of phenolic compounds, and their derived products could be used as ingredients for the development of functional foods and dietary supplements. However, the profile of nonextractable or macromolecular phenolic compounds in these samples has not been evaluated. Here, we show a comprehensive characterization of extractable and nonextractable phenolic compounds of a grape/pomegranate pomace dietary supplement using high-performance liquid chromatography–electrospray ionization–quadrupole time-of-flight (HPLC–ESI–QTOF) and matrix-assisted laser desorption/ionization (MALDI)-TOF techniques. The main extractable phenolic compounds were several anthocyanins (principally malvidin 3-O-glucoside) as well as gallotannins and gallagyl derivatives; some phenolic compounds were reported in grape or pomegranate for the first time. Additionally, there was a high proportion of nonextractable phenolic compounds, including vanillic acid, and dihydroxybenzoic acid. Unidentified polymeric structures were detected by MALDI-TOF MS analysis. This study shows that mixed grape and pomegranate pomaces are a source of different classes of phenolic compounds including a high proportion of nonextractable phenolic compounds.

中文翻译：

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高效液相色谱-电喷雾电离-四极杆飞行时间对葡萄/石榴渣渣膳食补充剂的可萃取和不可萃取的酚类化合物进行全面表征

葡萄和石榴是酚类化合物的丰富来源，其衍生产品可用作开发功能性食品和膳食补充剂的成分。但是，尚未评估这些样品中不可萃取或大分子酚类化合物的概况。在这里，我们展示了使用高效液相色谱-电喷雾电离-四极杆飞行时间（HPLC-ESI-QTOF）和基质辅助激光解吸对葡萄/石榴果渣膳食补充剂中可萃取和不可萃取的酚类化合物的全面表征/电离（MALDI）-TOF技术。可提取的主要酚类化合物是几种花色苷（主要是麦维京3-O-葡萄糖苷）以及没食子鞣质和没食子酰基衍生物。葡萄或石榴中首次报道了一些酚类化合物。另外，存在高比例的不可提取的酚类化合物，包括香草酸和二羟基苯甲酸。通过MALDI-TOF MS分析检测到未鉴定的聚合物结构。这项研究表明，葡萄和石榴混合的果仁糖是不同种类的酚类化合物的来源，其中包括大量不可提取的酚类化合物。