Integrated molecular sensory profiling reveals the distinct aroma signatures of peach fruit types

Aroma is a key attribute of peach fruits, yet the molecular basis of aroma differences among peach types remains poorly understood. This study comprehensively characterized the aroma profiles and identified key odor-active compounds distinguishing peaches from nectarines and across different flesh colors. Sensory evaluation using Check-All-That-Apply (CATA) revealed stronger fruity, sweet, floral, creamy, and tropical notes in peaches, whereas nectarine exhibited more green and waxy attributes. HS-SPME-GC-MS analysis of 44 peach cultivars identified 80 volatile compounds, and multivariate analysis (OPLS-DA) combined with relative odor activity values (ROAVs) showed that skin hairiness and flesh color significantly influence aroma composition. Nine and eight key volatiles were identified as major contributors to peach-nectarines differentiation and flesh color variation, respectively. Partial Least Squares Regression (PLSR) analysis suggested that lactones, terpenes, and norisoprenoids drive fruity, sweet, and floral notes in peaches, while some C6 compounds contribute to green and waxy attributes in nectarines. Furthermore, aroma addition and omission tests demonstrated the importance of key compounds, including linalool, β-ionone, γ-decalactone, hexyl acetate and nonanal for peaches, and linalool, (E)-2-hexenal and hexanol for nectarines in partially reconstructing characteristic aromas. These findings provide mechanistic insights into aroma differentiation and offer practical guidance for flavor-oriented breeding strategies.