Effects of Different LED Light-Quality Treatments on Bioactive Compounds and Instrumental Sensory Profiles of Tea Chrysanthemum

In this study, the bioactive compound contents and volatile profiles of postharvest ‘Nannong Jinju’ chrysanthemums under different light-quality treatments were analyzed using chemical assays, headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME–GC–MS), relative odor activity value (ROAV) calculations, electronic nose, and electronic tongue analyses. Differences in bioactive compound contents were observed among the light treatments, with blue light yielding the highest equally weighted composite index for the five measured bioactive compounds. GC–MS-based volatile profiling detected 1948 volatile metabolites, and higher relative abundances of several aroma-related compounds were observed under white light. Relative odor activity value analysis identified 60 potentially important aroma-related compounds. Principal component analysis suggested that several compounds, including octyl 2-methylpropanoate, germacrene D, and bornyl acetate were associated with the separation of white-light-treated samples and could serve as candidate discriminating compounds. Electronic nose and electronic tongue analyses further revealed distinct instrumental response patterns among the treatments. Overall, blue light was associated with the highest composite index of the five measured bioactive compounds, whereas white light was associated with higher relative abundances of several potentially aroma-relevant volatile compounds. These findings indicate that different postharvest light-quality treatments were associated with distinct changes in the chemical composition and instrumental aroma- and taste-related profiles of tea chrysanthemum.