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

TL;DR

This study optimizes the processing of osmanthus black tea using summer and autumn tea leaves, identifying key aroma compounds and achieving high sensory scores.

Contribution

The study introduces a novel method to utilize discarded summer and autumn tea leaves for osmanthus black tea production with optimized parameters.

Findings

Optimal processing achieved a sensory score of 92.2 with a 1:5.3 osmanthus-to-tea ratio and 16.6 hours of scenting.

GC–MS identified 259 volatile components and 14 key aroma-active compounds in osmanthus black tea.

Osmanthus black tea had twice as many alcohols/ketones and half as many esters compared to black tea base.

Abstract

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.

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.

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