Dynamic changes in volatile and non-volatile components of Jinggang honey pomelo (Citrus maxima (L.) Osbeck) during growth revealed through an untargeted metabolomics approach

We adopted HS-SPME-GC–MS and UPLC-Q-TOF/MS in our study to analyze changes in volatile components (VOCs) and non-VOCs during the growth of Citrus maxima cv. Jinggang honey pomelo. In total, 75 VOCs and 65 non-VOCs were identified. Terpenes were the most important components of the VOCs, D-limonene and germacrene D were the most representative. The contents of organic acids, flavonoids, coumarins, and amino acids gradually decreased throughout the growth process, while delayed bitter compounds (limonin and nomilin) continued accumulating. According to variable importance in the projection >1 and p  < 0.05, 25 non-volatile differential metabolites were selected. KEGG pathway analysis indicated that phenylpropanoid biosynthesis was the main pathway around which a sophisticated metabolic network was formed. The flavor of Jinggang honey pomelo evolved with changes in its components, ultimately presenting flavor characteristics of citrus and green aromas, balanced sweet and sour flavors, and a hint of bitterness in the aftertaste.