RESUMEN
The taste profile of oolong tea is intricately shaped by origins and roasting. Herein, a comprehensive approach integrating non-targeted metabolomics, quantitative analysis and sensory evaluations was employed to analyze the taste profile of oolong tea. 25 selected representative oolong teas, including Southern Fujian (MN), Northern Fujian (MB), and Taiwan (TW), were meticulously were classified into SX-RG-DD, GS, and TGY based on the chemical taste phenotypes. A total of 314 non-volatile compounds were identified, among which 87 and 77 compounds, including catechin, theaflavins, flavonoids and amino acids were screened as critical taste metabolites responsible for regions and roasting degree, respectively. The reduction of bitter and astringent, coupled with the enhancement of umami, sweet and sweet aftertaste exhibited a correlation with the decrease in (-)-epigallocatechin (EGC), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG), while the increase in catechin (C). These findings provide insights for further research on optimizing tea quality and refining processing techniques.
Asunto(s)
Biflavonoides , Camellia sinensis , Catequina , Metabolómica , Gusto , Té , Té/química , Metabolómica/métodos , Catequina/análisis , Catequina/análogos & derivados , Humanos , Biflavonoides/análisis , Camellia sinensis/química , Masculino , Flavonoides/análisis , Aromatizantes/análisis , Femenino , Aminoácidos/análisis , Adulto , ChinaRESUMEN
Roasting is pivotal for enhancing the flavor of Wuyi rock tea (WRT). A study investigated a novel compound that enhances the umami taste of WRT. Metabolomics of Shuixian tea (SXT) and Rougui tea (RGT) under light roasting (LR), medium roasting (MR), and heavy roasting (HR) revealed significant differences in nonvolatiles compounds. Compared LR reducing sugars and amino acids notably decreased in MR and HR, with l-alanine declining by 69%. Taste-guided fractionation identified fraction II-B as having high umami and sweet intensities. A surprising taste enhancer, N-(1-carboxyethyl)-6-(hydroxymethyl) pyridinium-3-ol (alapyridaine), was discovered and identified. It formed via the Maillard reaction, positively correlated with roasting in SXT and RGT. Alapyridaine levels were highest in SXT among the five oolong teas. Roasting tea with glucose increased alapyridaine levels, while EGCG inhibited its formation. HR-WRT exhibited enhanced umami and sweet taste, highlighting alapyridaine's impact on WRT's flavor profile. The formation of alapyridaine during the roasting process provides new insights into the umami and sweet perception of oolong tea.