Resumen de Characterization of Date (Deglet Nour) Seed Free and Bound Polyphenols by High‐Performance Liquid Chromatography‐Mass Spectrometry
Sameera Sirisena, Dimitrios Zabaras, Ken Ng, Said Ajlouni
Date (Pheonix dactyliferaL.) seeds are a valuable and abundant by‐product with various potential food applications. Free polyphenols (FPPs) and bound polyphenols (BPPs) of date seeds from Deglet Nourvariety grown in Australia were investigated using high‐performance liquid chromatography‐mass spectrometry. The FPP fraction contained the following main phenolic compounds per gram of date seed powder; procyanidin B1 (499.8 ± 7.8 μg), procyanidin B2 (288.6 ± 6.1 μg), catechin (167.6 ± 2.1 μg), epicatechin (39.44 ± 0.39 μg), and protocatechuic acid (1.77 ± 0.22 μg). Additionally, one of the 2 A‐type dimers was confirmed as procyanidin A2 (24.05 ± 0.12 μg/g). A‐type dimers have not been reported before in date seeds. The BPP fraction contained epicatechin (52.59 ± 0.76 μg/g) and procyanidin B2 (294.2 ± 3.7 μg/g), while several peaks exhibiting ESI−m/z of 153 indicated dihydroxybenzoic acid isomers including protocatechuic acid (2.138 ± 0.025 μg/g). These findings contributed to our knowledge of date seed phytochemicals and understanding of their contribution to the reported bioactivities. Date seed extracts are rich in polyphenols and have shown various bioactivities. However, there is limited research on chemical characterization of date seed antioxidants. This study enhances the knowledge on date seed polyphenols, thus the data can be used to support the development and marketing of current and new food products incorporating date seed extracts.
