How Light Spectra Reshape the Volatile Metabolome and Aroma Profile of Celery: Natural Greenhouse Light Vs. Artificial LED Light

Light spectral quality strongly influences volatile formation, yet its effects on celery petioles remain unclear. Celery petioles grown under natural greenhouse light (CK), warm-white (3000K), cool-white (6500 K), and red-blue (RB) LEDs were evaluated using HS-SPME-GC–MS-based volatile metabolomics and relative odor activity values. A total of 1789 VOCs were detected and tentatively identified, dominated by terpenoids, esters, ketones, heterocyclic compounds, and alcohols. Among the four light treatments, RB produced the clearest multivariate separation and the largest number of up-accumulated aroma-related volatiles, whereas the two white LEDs generated comparatively similar profiles. Red-blue light responsive volatiles were associated with terpenoid, phenylalanine, amino acid, and central carbon metabolism. The rOAV analysis highlighted (5Z)-octa-1,5-dien-3-one, 2-methoxy-3,5-dimethylpyrazine, limonene, and ocimene isomers as candidate odor-active markers of celery-petiole aroma. These results support red-blue spectral management for flavor-oriented celery production in controlled environments.