Changes in Components During Quality Formation and Evaluation of Honey-Processed Glycyrrhiza uralensis Fisch. from Different Geographical Origins by Sequential Electrospray Ionization Mass Spectrometry

To explore the changes in quality formation during the honey-processing of Glycyrrhiza uralensis from six geographical origins, including Inner Mongolia, Xinjiang, Anhui, Gansu, Guangdong, and Jiangxi. In this study, raw G. uralensis was mixed with honey and smoldered, then heated and stir-fried, and finally cooled. The water-soluble components (WSCs) and methanol-soluble components (MSCs) in G. uralensis were simultaneously analyzed by sequential electrospray ionization mass spectrometry (SESI-MS) without the need for complex sample pretreatment. Fifteen WSCs (e.g., proline, arginine, serine, glabrol, monosaccharides, disaccharides, and trisaccharides) and twenty-eight MSCs (e.g., liquiritigenin, naringenin, glycyrrhizic acid, glycyrrhetinic acid, and formononetin) were identified within 2 min. Both principal component analysis and partial least-squares discrimination analysis showed that samples of honey-processed G. uralensis (HPGU) from six different geographical origins were effectively distinguished; liquiritin, daidzein, sinapic acid, and ferulic acid were identified as potential differential metabolites by variable importance for the projection; and the contents of saccharides, glabridin, formononetin, glabrol, and glycyrrhetinic acid were high in HPGU. Meanwhile, Inner Mongolia showed the highest contents of glycyrrhetinic acid and daidzein, suggesting these samples may possess superior quality based on these specific markers. SESI-MS could enhance our understanding of the changes in quality formation during the honey-processing of G. uralensis.