Black tea aroma formation during the fermentation period

Variation in Volatile Compounds of Raw Pu-Erh Tea upon Steeping Process by Gas Chromatography–Ion Mobility Spectrometry and Characterization of the Aroma-Active Compounds in Tea Infusion Using Gas Chromatography–Olfactometry–Mass Spectrometry

“…It was found through the SBSE method that alcohol compounds also occupied a large proportion in the RAPT infusion (Figure A), such as 1-octen-3-ol, pentanol, hexanol, octanol, geraniol, heptanol, linalool, and phenylethanol (Table ). The contents of these alcohols usually increased during the rolling stage, which consumed fatty acids to produce aroma compounds . Linalool (OAV 356, AI 5.97) and geraniol (OAV 9, AI 5.78) were derived from the same precursor substance (geranyl pyrophosphate) by different synthases and possessed typical floral attributes, which could decrease the intensity of roasted attributes of the tea. , Zhu et al concluded that some volatiles with lower boiling points and effumability in teas released into the headspace of tea infusion might lead to the loss and distortion of the whole aroma extracts with the method of SBSE, which also supported the importance of combining multiple pretreatments for a convictive profile of RAPT infusion …”

Assessment of Variations in Round Green Tea Volatile Metabolites During Manufacturing and Effect of Second-Drying Temperature via Nontargeted Metabolomic Analysis

“…From the 51 compounds obtained in section Differential Compound Screening and Evolution Analysis During RGT Processing, the metabolic transformation rules of 34 key volatile compounds with definite aroma characteristics ( 9 , 13 ) were revealed. Combined with the transformation and metabolism-related substances, this study clarified the evolutionary law of total 48 volatile compounds in the process of RGT, which contained 21 fatty acid-derived volatile substances, 18 glycoside-derived volatile substances, 7 amino acid-derived volatile substances, and 3 carotenoid-derived volatiles ( Supplementary Figure S1 ).…”

“…In tea, the volatile compounds arise from two sources—fresh tea leaves and substances formed during processing. These substances can be classified into four categories from different precursors: amino acid-derived volatiles, wherein amino acids undergo a Strecker reaction under the action of heat, and Maillard reaction with sugars to produce aldehydes, ketones, furans, pyrazines, and high-boiling volatile compounds ( 9 , 10 ); glycoside-derived volatiles and glycoside-derived Non-volatiles, which release bound volatile compounds such as linalool and geraniol under the action of glycosidase or heat ( 11 ); lipid-derived volatiles, wherein lipids are first degraded to produce linolenic acid and other fatty acids, followed by production of lower-pointing alcohols and aldehydes ( 12 ); and carotenoid-derived volatiles, wherein carotenoids are precursors of volatile compounds such as ionone, 2,6,10,10-tetramethyl-1-oxaspiro[4.5]dec-6-en-8-one, and β-tanshinone ( 13 ).…”

Effect of Fermentation Humidity on Quality of Congou Black Tea

“…The black tea manufacturing process mainly includes the steps of withering, rolling (rolling-cutting), fermentation and drying, with fermentation being a very important step due to the formation of the main taste substances and the accumulation of aroma substances at this stage [ 2 ]. Under the impact of polyphenol oxidase and peroxidase, enzymatic reactions occur in polyphenolic components in black tea during fermentation, leading to their transformation into a variety of characteristic oxidation products, such as tea pigments, which contribute to the generation of the unique aroma, taste, color and function of black tea [ 3 , 4 ].…”