Tea Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Key Laboratory of Tea Plant Resources Innovation & Utilization, Guangzhou, China.
J Food Sci. 2022 Aug;87(8):3433-3446. doi: 10.1111/1750-3841.16248. Epub 2022 Jul 15.
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.
采用顶空固相微萃取-气相色谱-质谱联用技术对来自 7 个国家的 112 种红茶中的挥发性风味化合物进行了非靶向代谢组学分析。采用多元统计分析和气味活度值（OAV）对这些样品进行分类，并鉴定关键气味物质。共鉴定出 140 种挥发性风味化合物（VFCs），包括 12 个不同组，其中醇类在来自中国和印度的样品中较为普遍，分别占总 VFCs 的 40.83%和 34.96%。在来自中国、印度和斯里兰卡的样品中，有 8 种挥发性化合物的 OAV 值大于 1，被鉴定为关键的活性差异气味物质，包括芳樟醇、戊酸、甲基水杨酸、己酸、1-甲基萘、苯乙醇、香叶醇和β-紫罗兰酮。印度红茶中的芳樟醇、戊酸和己酸、中国红茶中的苯乙醇以及斯里兰卡红茶中的 1-甲基萘和β-紫罗兰酮可用于区分不同的红茶组。在广东英德红茶中，有 12-14 种 OAV 值大于 1 的 VFC 被鉴定为关键的活性芳香化合物。在台湾红茶中，有 3 种 OAV 值大于 1 的挥发性化合物被鉴定为关键的活性芳香化合物，分别为香叶醇和苯乙醛、甲基水杨酸；在安徽红茶中，有 1 种 OAV 值大于 1 的挥发性化合物被鉴定为关键的活性芳香化合物，为苯乙酸。感官评价结果表明，大多数红茶都呈现出常见的甜味和花香气味，这与 GC-MS 分析结果一致。这些结果将有助于描述红茶的气味代谢组，并为鉴别不同红茶的真实性提供生化基础。实际应用：印度红茶中的芳樟醇、戊酸和己酸，中国红茶中的苯乙醇，斯里兰卡红茶中的 1-甲基萘、β-紫罗兰酮和甲基水杨酸可用于区分来自这三个国家的红茶。英德红茶中的芳樟醇和苯乙醛、台湾红茶中的甲基水杨酸、安徽红茶中的苯乙酸是区分这些红茶与其他中国红茶的潜在生物标志物。
