Flavor characteristic and characterization of key sweet aroma compounds in Camellia nanchuanica black tea.

Camellia nanchuanica (NC) black tea has garnered attention for it's appealing sweet taste and aroma. Previously, phloridzin was identified as the key sweet taste compound in NC black tea. To investigate the aroma characteristic of NC black tea, a flavor wheel containing 54 flavor attributes, was developed using 30 samples of NC black tea. Sweet aroma was identified the most prominent characteristic aroma attribute of NC black tea. To further reveal the key sweet aroma compounds, 112 volatile compounds were totally detected using gas chromatography-mass spectrometry. Among them, β-ionone, linalool, phenylacetaldehyde, octanal, and geraniol were the potential key sweet aroma compounds in NC black tea because their relative odorant activity values and odorant activity values were exceeded 1. Notably, when β-ionone, linalool, and geraniol concentrations were 47.17-94.35, 168.02-336.03, 376.79-753.58 μg/L primarily with floral and sweet aroma, significantly enhanced the sweet aroma of NC black tea. Generally, our work not only revealed the flavor characteristics of NC black tea but analyzed its key sweet aroma compounds, which provided a theoretical basis for improving its higher sweet aroma.