Molecular Mechanism of Mature Honey Formation by GC-MS- and LC-MS-Based Metabolomics.

Honey maturity is an important factor in evaluating the quality of honey; however, there are few studies on the molecular mechanism of the formation of mature honey (MH). In this study, the different metabolites of stomach honey (SH), immature honey (IMH), and MH samples during the same rapeseed flower season were analyzed by an UPLC-QTOF-MS-based metabolomics approach. MH was found to have a distinct metabolic profile to IMH, and a total of 9 different metabolites were obtained, 3 of which, including decenedioic acid, were accumulated in MH. Decenedioic acid as a bee-originated fatty acid (FA) was further verified in rape, acacia, and jujube honey by GC-MS, making it a potential marker to discriminate IMH and MH (P < 0.01). Besides, MH showed higher FAs concentrations; in particular, 3 FAs were significantly richer in MH than IMH (P < 0.05). This study reveals the molecular mechanism from IMH to MH from a FA perspective.