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Guangdong black teas have diverse flavors and aromas. To explore the molecular basis of these aromas, we extracted and analyzed the volatile flavor compounds of 31 black tea samples from 7 districts (Yingde, Luokeng, Renhua, Meizhou, Chaozhou, Lianshan, and Heyuan) in Guangdong Province with headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS). Then, 135 volatile flavor compounds (VFCs) were identified and grouped into 12 classes according to their chemical structure. Notably, alcohols accounted for 31.40–44.43% of total VFCs. The score plot of supervised partial least squares-discriminant analysis (PLS-DA) revealed good discrimination for most black tea samples. Additionally, 64 compounds with variable importance in projection > 1.0 were identified as differential odorants. Through an odor activity value analysis, eight volatile compounds were identified as the key active differential VFCs: linalool, methyl salicylate, phenylethyl alcohol, p-cresol, 3-methyl-butanoic acid, geraniol, benzaldehyde, and benzeneacetaldehyde. Thus, benzeneacetaldehyde and linalool in YJ-Yingde samples, benzaldehyde in Luokeng samples with an almond-like aroma, phenylethyl alcohol in the Heyuan samples, and p-cresol and 3-methyl-butanoic acid in the Chaozhou samples were the key volatile flavor compounds that could differentiate local black teas from other black teas. These findings will enrich the research in tea aroma chemistry and provide a method for identifying the origins of Guangdong black teas. [ABSTRACT FROM AUTHOR]

Volatile flavor compounds in 112 black teas from seven countries were analyzed by untargeted metabolomics using headspace solid‐phase microextraction and gas chromatography‐mass spectrometry (HS‐SPME/GC‐MS). Multivariate statistical analysis and odor activity values (OAVs) were used to classify these samples and identify key odorants. A total of 140 volatile flavor compounds (VFCs), including 12 different groups, were identified, and alcohols were prevalent in China and India samples, accounting for 40.83% and 34.96% of the total VFCs, respectively. Eight volatile compounds with OAVs > 1 were identified as key active differential odorants in Chinese, Indian, and Sri Lankan samples, including linalool, pentanoic acid, methyl salicylate, hexanoic acid, 1‐methyl‐naphthalene, phenylethyl alcohol, geraniol, and β‐ionone. Linalool, pentanoic acid, and hexanoic acid in Indian black teas, phenylethyl alcohol in Chinese black teas, and 1‐methyl‐naphthalene, β‐ionone in Sri Lankan black teas could be used to discriminate different black tea groups. A total of 12–14 VFCs with OAVs > 1 were identified as key active aromatics in Chinese black tea sample. Linalool and benzeneacetaldehyde in Yingde (Guangdong) black tea, methyl salicylate in Taiwanese samples, and benzeneacetic acid in Anhui black tea could be used as biomarkers to distinguish them from other Chinese samples. Sensory evaluation results showed that most black teas presented the common sweet, floral odors, which were consistent with GC‐MS analysis. These results will contribute to characterize the odor metabolome of black teas and provide biochemical basis for identifying the authenticity of different black teas. Practical Application: Linalool, pentanoic acid, and hexanoic acid in Indian black teas, phenylethyl alcohol in Chinese black teas, 1‐methyl‐naphthalene, β‐ionone, and methyl salicylate in Sri Lankan black teas could be used to discriminate black teas from the three countries. Linalool and benzeneacetaldehyde in Yingde black teas, methyl salicylate in Taiwanese black teas, and benzeneacetic acid in Anhui black tea are the potential biomarkers to distinguish these teas from other Chinese black teas. [ABSTRACT FROM AUTHOR]

Wild black tea varieties with almond odors were found in Guangdong, China. Few previous studies have investigated their metabolic profile during processing. Herein, we assessed the variations in the chemical components including the volatile flavor compounds and nonvolatile flavor components during black tea processing. Benzaldehyde was responsible for the almond odor and could be used as an indicator for identifying black tea varieties with almond odors because of its relative stability. The contents of aromatic compounds with floral, sweet, and honey-like aromas, such as (E)-geraniol, phenylethyl alcohol, benzyl alcohol, β-ionone, α-terpineol, and (Z)-geraniol, were higher in the final drying process than they were in the plucking stage. However, the contents of β-linalool and its oxides and methyl salicylate tended to be lower in the dried black teas. PCA showed that 88.41% of the variation between the aromatic compounds and their odor attributes can be explained by PC1 and PC2. The almond flavor samples were differentiated from the control samples according to PCA. The contents of nonvolatile flavor components such as tea polyphenols, amino acids, soluble carbohydrates and caffeine were significantly lower in the dried black teas. The sensory evaluation suggested that XR black teas had strong and lasting almond odors, while DX-8 had floral and medicinal odors. [ABSTRACT FROM AUTHOR]

Volatile flavor compounds (VFCs) and nutrients in Viscum articulatum Burm.f. parasitic on ancient tea trees (named TM) were studied in this research by headspace solid‐phase microextraction (HS‐SPME)/gas chromatography–mass spectrometry (GC–MS) and conventional methods. Sixty‐six volatile compounds belonging to different classes were identified by GC–MS. The ketones, alcohols, and aldehydes were the principal aroma groups in TM according to principle component analysis (PCA). The most abundant aroma components in TM included benzaldehyde (9.64%), geranylacetone (7.92%), epoxy‐β‐ionone (7.71%), β‐linalool (7.35%), methyl salicylate (6.96%), and hotrienol (6.14%), significantly higher than CKs (p < .05). The positive PC1 and PC2 in TM were correlated with benzaldehyde, hotrienol, methyl salicylate, and geranylacetone. The mistletoes could be differentiated from CKs due to the difference in aroma compounds. Clean and fresh, woody and nutty odor with minor floral scent was the characteristics of TM. Analysis of the nutritional components showed that contents of polyphenols and catechins in TM were at trace levels, significantly lower than CKs (p < .05). The total contents of polyphenols, amino acids, carbohydrates, and caffeine in TM were significantly lower from the total soluble solids (p < .05), indicating that there were still lots of compounds undetected in TM. The sensory test showed that the taste and aroma in TM can be accepted, which indicates TM could be developed into alternative tea drinks in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sixteen aroma compounds were identified as key compounds to distinguish FHDC and TGY. • Twenty compounds were selected as typical markers for the 10 FHDC fragrance types. • Benzyl nitrile and phenylethyl alcohol in RG are key markers to distinguish others. • β -Pinene in JH, and α -phellandrene in ZL are key aroma markers to distinguish others. Fenghuang Dancong tea (FHDC), a famous oolong tea originating from Guangdong Province in China, is known for its rich and unique fragrance. Nevertheless, the identification of the key aroma compounds with the difference fragrance types of FHDC remains uncertain. In order to characteristic the volatile components in different fragrance types of FHDC, 10 well-known fragrance types of FHDC and Tieguanyin (TGY) as a control were analyzed by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography mass spectrometry (GC–MS). Results indicated that 172 volatile compounds were identified as common volatile compounds among all the tea samples. A total of 16 compounds were identified as key compounds that could be used to distinguish between FHDC and TGY. Among the 10 FHDC fragrance types, indole, hotrienol, benzyl nitrile, and jasmine lactone were found to be the most abundant compounds. Despite the presence of certain similarities in aroma components, each type exhibits unique fragrance characteristics as a result of variation in compound composition content and proportion. Furthermore, using statistical and odor activity value analysis, 20 aroma-active compounds were recognized as potential characteristic markers accountable for the diverse fragrance types of FHDC. This research enhances our comprehension of the various fragrance types of FHDC and provides reference values for their rapid identification in the market. [ABSTRACT FROM AUTHOR]