Analysis of aroma‐active volatiles in an SDE extract of white tea

Abstract

White tea is a famous Chinese tea that is cooked at boiling point before drinking. The simultaneous distillation‐extraction (SDE) was used to collect volatile compounds during tea cooking. The SDE extract was dominated with green, floral, roasted and woody notes, and weak sweet note. There were 32 volatile compounds identified via gas chromatography–mass spectrometry analysis, and 19 of them had strong fragrance based on the gas chromatography‐olfactometry analyzed results. Hexanal, 2‐hexenal, cis‐3‐hexen‐1‐ol, and camphene were the main contributors to the green note. The floral note was mainly contributed by 2‐hexanone, benzeneacetaldehyde, trans‐linalool oxide, and linalool, and the sweet note was induced by trans‐β‐damascenone. The roasted note was mainly contributed by 2‐pentyl‐furan. The woody note was mainly contributed by trans‐α‐ionone and trans‐β‐ionone. Four putative reaction pathways, including amino acid degradation, carotene degradation, Maillard reaction, and glycosides hydrolysis, were figured out to explain the generation of aromatic‐active volatiles at high temperatures. This study added our knowledge on tea aroma under cooking as well as other thermal treatments.

Effects of Various Processing Methods on the Metabolic Profile and Antioxidant Activity of Dendrobium catenatum Lindley Leaves

“…Rolling had no observable effects; however, the rolled leaf was easier to brew into a goodappearance tea, which may because the foliage cuticle and cell walls were destroyed during the rubbing process [14]. Furthermore, high-temperature pretreatment was conducive to form Maillard reaction products (MRPs), which markedly contribute not only to the aroma, taste and color but also to the antioxidant activity [30,31].…”

The characteristic of the key aroma‐active components in white tea using GC‐TOF‐MS and GC‐olfactometry combined with sensory‐directed flavor analysis

“…Qi et al 6 reported that 2-amylfuran was the main source of roasted aroma of white tea, its aroma intensity increased during the aging process of white tea. Similarly, Lin et al 11 found that 2-amylfuran was the main product during the drying process of white tea. Only one aroma-active compound which showed the aged fragrance, was sensed in WT-5, but unfortunately this compound was not identified.…”

“…Ma et al 19 identified 24 aroma‐active components from Pu‐erh tea by using GC‐O and DF. Odor activity values (OAVs), 11 recombination and omission experiments have been applied to study key aroma‐active components in tea samples 17 . In our previous studies, phenylacetaldehyde, linalool, geraniol and 3‐ethyl‐2,5‐dimethylpyrazine were identified as the key aroma‐active compounds of high‐grade Dianhong tea (DHT) by OAVs and sensory‐directed aroma recombination and omission tests 20 …”

“…9 Different extraction methods of volatile compounds from white tea were compared in previous reports. 10,11 In addition, the volatile compounds in white tea and their dynamic changes during the manufacturing process as well as tea cooking process have been studied, and some volatile compounds such as amino acid-derived volatiles (AADVs) changed. 12 However, the dynamic change of aroma profile as well as the key aroma-active compounds of white tea during the aging process are still unclear.…”

“…Volatile compounds of white teas from different areas in Fujian Province, the main producing areas of white tea, were also investigated and white teas from different origins were shown to have characteristic volatile organic compounds and profiles 9 . Different extraction methods of volatile compounds from white tea were compared in previous reports 10,11 . In addition, the volatile compounds in white tea and their dynamic changes during the manufacturing process as well as tea cooking process have been studied, and some volatile compounds such as amino acid‐derived volatiles (AADVs) changed 12 .…”