Optimization of processing technology and analysis of aroma components of osmanthus black tea using summer and autumn tea leaves

Tea is mainly produced with spring tea leaves. Summer and autumn tea leaves, characterized by a bitter and astringent taste, are usually discarded. Here, they were turned into osmanthus black tea, and the processing technology was optimized. Optimum process: the ratio of osmanthus to tea was 1:5.3, 16.6 h scenting, two cycles, the highest sensory score was 92.2. E -nose showed significant differences in response values among the W5S, W1W, and W2S sensors. Samples 6, 9, 11, and 12 exhibited high response values across multiple sensors. GC–MS was used to analyze volatile components in osmanthus black tea and the black tea base. A total of 259 volatile components were identified, and 14 key aroma-active compounds were screened, including β-ionone, γ-dodecalactone, γ-decalactone, phenylethanol, and linalool. • Optimized osmanthus black tea processing from summer-autumn leaves, with top sensory score 92.2 under specific conditions. • 259 volatile components were identified by gas chromatography–mass spectrometry, and 14 key aroma-active components were screened out. • Osmanthus black tea had ~2× more alcohols/ketones, half the esters vs black tea base, higher total aroma.