Comparative Analysis of Pu-erh and Fuzhuan Teas by Fully Automatic Headspace Solid-Phase Microextraction Coupled with Gas Chromatography–Mass Spectrometry and Chemometric Methods

Abstract

Thirteen Pu-erh teas and 13 Fuzhuan teas obtained from two different production areas in China were profiled using fully automatic headspace solid-phase microextraction (HS-SPME)/gas chromatography-mass spectrometry (GC-MS) coupled with chemometric methods. A total of 93 aroma components were identified in 26 dark teas; among them, methoxyphenolic compounds (31.77%) were the most abundant components in Pu-erh teas, whereas ketone compounds were the most abundant components (25.42%) in Fuzhuan teas. Cluster analysis (CA) and principal component analysis (PCA) showed that these two types of dark teas could be clearly distinguished according to their chemical characteristics. This study suggested that the proposed strategy could provide a feasible and rapid technique to differentiate dark teas with similar morphological characteristics from different production areas by their volatile composition and relative content.

Volatile compounds and sensory characteristics of various instant teas produced from black tea

“…Two nitrogen containing heterocyclic compounds, namely 1-ethyl-1H-pyrrole and 1-ethyl-2-pyrrolecarboxaldehyde, were identified. These compounds have previously been reported in various tea samples (Du et al, 2014;Joshi & Gulati, 2015;Lv et al, 2014).…”

“…The most abundant volatile compounds among tea samples was methyl acetate, which ranged from 108 to 1455 ng/g, being lowest in SDIT and highest in DCIT. Methyl salicylate was previously identified in tea samples and recognized as important compound for the overall tea aroma formation (Lv et al, 2014;Wang et al, 2008). Unsaturated ester, methyl-3-hexenoate, was only detected in black tea and it is likely formed from 3-hexenoic acid which was identified in our previous study (Alasalvar et al, 2012).…”

“…It has been reported that 1-octen-3-ol exerts a mushroom odour and plays a significant role in the overall aroma formation of various foods due to its low threshold. This compound was previously identified in tea flowers (Joshi, Poonam, & Gulati, 2011) and Pu-erh and Fuzhuan teas (Lv, Wu, Li, Xu, Liu, & Meng, 2014). Two isomers of 2,3-butanediol were found in tea samples.…”

“…Two isomers of 2,3-butanediol were found in tea samples. Previously, 2,3-butanediol was reported in Chinese dark tea (Lv et al, 2014). Alcohols may be resulted from the oxidative degradation of fatty acids.…”

Sense of smell and volatile aroma compounds and their role in the evaluation of the quality of products of animal origin – a review

“…One-dimensional gas chromatography (GC), based on separation of components of a mixture on one column, is a basic chromatographic technique used to analyse volatile substances in food products Lv et al, 2014;Tu et al, 2014;Lv et al, 2015;Majcher et al, 2015). However, it is not always sufficient for analyses of complex mixtures and therefore for the last twenty five years twodimensional gas chromatography, which is more efficient and shows greater resolution power, is under increasingly intensive development.…”