Elucidation of flavor codes in citrus fruit peels using electronic sensors, LC-MS/MS, and GC-MS combined with GC-O.

This study integrated biomimetic sensors with targeted taste compounds (organic acids; OAs and free sugars; FSs) and odor compounds profiling GC-MS-O to characterize citrus fruit peels (CFP) across seven cultivars. Among FSs, fructose and glucose were predominant (range: 25.68-8.16 mg/g and 24.11-7.51 mg/g, respectively), while sucrose was highest in kumquat peel (KP) (18.48 ± 0.19 mg/g). Citric acid and quinic acid were the major OAs, with citric acid peaking in KP (2152.38 ± 18.84 mg/kg) and quinic acid in lemon peel (LP) (1018.75 ± 15.90 mg/kg) (p < 0.05). E-tongue profiles revealed clear cultivar-dependent separation along [sourness/sweetness/umami] dimensions, consistent with the acid-sugar balance. Odor compounds analysis identified 60 compounds, and GC-O/odor-active value (OAV) highlighted odor compounds (decanal, α-pinene, limonene, 2-carene, and γ-muurolene) as key odor contributors (OAV > 1). Multivariate integration linked sensor outputs to metabolite signatures, providing an evidence-based framework to prioritize CFP types for targeted flavor applications.