UHPLC-HRMS quantitative analysis of monoglycosylated aroma precursors in grape must using factorial design for extraction protocol optimization

Wine aromas precursors are of utmost importance in the winemaking process, as they release volatile compounds pivotal for wine flavour and taste, after hydrolysis during fermentation. Several analytical methods are present in literature for glycosylated wine aromas, almost limited to identification and characterization, while accurate quantitative data are still difficult to be collected. In this work, we developed a protocol for aroma glycosides quantification in grape musts by UHPLC-ESI-HRMS. Design of Experiment was used to optimize the extraction and pre-concentration method of three classes of glycosylated aromas, as well as the ESI source parameters to increase their ionization efficiency. The performance of the method was validated on synthetic musts in terms of linearity (r² > 0.994), precision (RSD ≤ 9%), accuracy, recovery and matrix effect (71-102%). The method was further tested in real samples to quantify aroma precursors in 10 samples of Italian and French musts, highlighting phenolic and aliphatic glycosides as the most abundant classes.