# Lipid and volatile dynamics shape sweet potato and honey aroma in ‘Baiye 1’ black tea

## TL;DR

This study identifies how lipid and volatile compound changes during processing give ‘Baiye 1’ black tea its unique sweet potato and honey aroma.

## Contribution

The study reveals lipid metabolism's role in shaping the aroma of high-amino-acid black tea through metabolic pathway analysis.

## Key findings

- Six non-volatile compounds contribute to the sweet and umami taste of ‘Baiye 1’ black tea.
- Eight volatile compounds, including β-ionone and geraniol, are responsible for the sweet potato and honey aroma.
- Lipid transformations during rolling and drying release precursors for key aroma components.

## Abstract

The albino tea cultivars represented by ‘Baiye 1’, characterized by their naturally enriched amino acid content and reduced polyphenol levels, exhibit distinctive sweet and umami flavors along with honey-like aromas, characteristics that are uncommon in traditional black teas. Nevertheless, the metabolic transformations underlying these superior sensory qualities during processing remain insufficiently understood. Here, UPLC-HRMS and HS-SPME-GC–MS/MS were employed to analyze non-volatile and volatile compounds respectively during ‘Baiye 1’ black tea (BYBT) processing. Six non-volatile compounds were identified as key taste components responsible for BYBT's sweet, umami, and mild flavors, while eight aroma-active volatiles, including β-ionone and geraniol, collectively shaped BYBT's baked sweet potato and honey-like aroma. Interestingly, lipidomics and aroma formation pathway analysis revealed that lipid transformations during rolling and drying released precursors and generated key aroma components, highlighting the pivotal role of lipid metabolism in aroma formation. Our work elucidates the flavor development mechanisms of high-amino-acid black tea and offers biochemical insights for optimizing processing and enhancing the value of specialty cultivars like ‘Baiye 1’.

Unlabelled Image

•Sweetness (L-Met, L-Ser, L-Pro) and umami (L-Asn, GABA) markers enhance BYBT taste.•Eight VOCs identified as key contributors to sweet potato and honey-like aromas.•Rolling increases AGs and GPLs, degrades GLs, and shapes BYBT flavor.•Lipid oxidation and Maillard reactions drive BYBT aroma formation pathways.

Sweetness (L-Met, L-Ser, L-Pro) and umami (L-Asn, GABA) markers enhance BYBT taste.

Eight VOCs identified as key contributors to sweet potato and honey-like aromas.

Rolling increases AGs and GPLs, degrades GLs, and shapes BYBT flavor.

Lipid oxidation and Maillard reactions drive BYBT aroma formation pathways.