# Sensomics-assisted identification of key aroma components contributing to the characteristic scent of vacuum-extracted Jin Guanyin tea hydrolat and its aroma enhancement potential

## TL;DR

This study identifies key aroma compounds in Jin Guanyin tea hydrolat and shows how vacuum extraction can enhance tea aroma for commercial use.

## Contribution

First investigation of Jin Guanyin Oolong tea hydrolat under vacuum extraction and identification of key aroma components.

## Key findings

- Low-temperature, short-duration extraction (50°C for 40 min) best preserves tea hydrolat aroma quality.
- Key aroma components like jasmine lactone and methyl salicylate were identified using sensory and analytical methods.
- Hydrolat application increased key aroma components in tea by up to 20.69%.

## Abstract

Tea hydrolat is an innovative value-added tea product with natural tea aroma. Nevertheless, the dearth of research has hindered its industrial development and commercialization. Therefore, this study is the first to investigate the Jin Guanyin Oolong tea hydrolat under vacuum extraction. Sensory evaluation and volatile analysis revealed that low-temperature, short-duration extraction (optimally 50 °C for 40 min) better preserved aroma quality. The 40 aroma components were detected by gas chromatography-olfactometry, and subsequently jasmine lactone, benzeneacetaldehyde, methyl salicylate, hexanal, benzaldehyde, indole, jasmone, methyl heptenone, β-ionone, (Z)-3-hexen-1-ol, and 1-penten-3-one were identified as the key aroma components of the tea hydrolat based on the aroma recombination and omission tests. Hydrolat scenting demonstrated excellent aroma-enhancing efficacy in tea, achieving up to a 20.69 % increase in key aroma components. These findings indicated the substantial potential for tea hydrolat application in increasing the added value of tea aroma in industry.

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•Optimal JGY hydrolat extraction was at low temperature-short duration (50 °C, 40 min).•Extraction kinetic models for key volatiles were successfully established.•Key fresh floral components in JGY hydrolat were identified (e.g., jasmine lactone).•JGY hydrolat could enhance fresh floral, fruity, and sweet aromas of tea leaves.

Optimal JGY hydrolat extraction was at low temperature-short duration (50 °C, 40 min).

Extraction kinetic models for key volatiles were successfully established.

Key fresh floral components in JGY hydrolat were identified (e.g., jasmine lactone).

JGY hydrolat could enhance fresh floral, fruity, and sweet aromas of tea leaves.