Unravelling the polyphenolic content of berry juices using focusing-modulated comprehensive two-dimensional liquid chromatography

Introduction

In this work, a comprehensive two-dimensional liquid chromatography system, comprised of HILIC and C18 columns in the first and second dimension, respectively, was tuned and employed to attain the profiles of polyphenolic compounds occurring in seven commercial berry juices. A total of 104 polyphenolic compounds belonging to different chemical classes (hydroxybenzoic and cinnamic acids derivatives, flavone glycosides, flavonols, flavonol glycosides, dihydroflavonols, and anthocyanin glycosides) have been characterized and quantified in the juices investigated. Despite the phenolic constituents were similar, the contents varied considerably among the analyzed berry species. Elderberry contained the highest amount of polyphenols (917.79 mg 100mL-1), followed by chokeberry (515.73 mg 100 mL-1). On the other hand, raspberry contained the lowest amount 103.56 (515.73 mg 100mL-1). The developed HILIC ×RP-LC method showed a remarkable separation capability, being characterized by high values of corrected peak capacity (up to 1372) and orthogonality (A.o. up to 0.8). Such a HILIC×C18 platform based on focusing modulation, never employed so far for berry juices, provided great applicability to be advantageously employed for other complex food samples.

May 14, 2023 GMT