Huang Haoran, Chen Xinyu, Wang Ying, Cheng Ye, Liu Zhijian, Hu Yunchao, Wu Xianzhi, Wu Caie, Xiong Zhixin
College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing, China.
School of Electrical and Optoelectronic Engineering, Changzhou Institute of Technology, Changzhou, China.
J Food Sci. 2024 Dec;89(12):9137-9153. doi: 10.1111/1750-3841.17535. Epub 2024 Dec 4.
This paper studied the influence of storage duration on the flavor profile of white tea in detail, with samples produced between 2020 and 2023. Sensory evaluation was performed by quantitative descriptive analysis (QDA), followed by an in-depth aroma components analysis employing an electronic nose (E-nose), headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The QDA findings revealed a gradual transition in the flavor profile of white tea during storage, shifting from sweet, fruity, and floral to more herbal and stale characteristics. E-nose could well distinguish white tea with different storage times. A total of 55 and 53 volatile compounds were identified by HS-GC-IMS and HS-SPME-GC-MS, respectively. The orthogonal partial least squares-discriminant analysis models, based on HS-GC-IMS (RY = 0.998, Q= 0.987) and HS-SPME-GC-MS (RY = 0.984, Q = 0.993), successfully distinguished white tea samples stored for different storage times. Furthermore, 14 and 8 key compounds were screened based on the double variable criterion of one-way analysis of variance (p < 0.05) and variable importance in projection (VIP) >1.2, and their content changes were also compared. It is the gradual decrease of important aroma components such as 2-hexenal, 2-methyl-2-hepten-6-one, linalool, and geraniol, which are positively correlated with sweet, fruity, and floral aromas, and the gradual increase of hexanoic acid, thiophene, propanoic acid, dimethyl disulfide, and borneyl acetate, which are positively correlated with herbal and stale flavor, that leads to the changes in flavor and aroma of white tea during storage. The results of the study provided a reference for elucidating the aroma characteristics of white tea at different storage times as well as a theoretical basis for the quality control of white tea.
本文详细研究了储存时长对2020年至2023年间生产的白茶风味特征的影响。通过定量描述分析（QDA）进行感官评价，随后采用电子鼻（E-nose）、顶空气相色谱-离子迁移谱（HS-GC-IMS）和顶空固相微萃取-气相色谱-质谱联用（HS-SPME-GC-MS）对香气成分进行深入分析。QDA结果显示，白茶在储存过程中风味特征逐渐转变，从甜、果、花香转变为更具草本和陈腐特征。电子鼻能够很好地区分不同储存时间的白茶。HS-GC-IMS和HS-SPME-GC-MS分别鉴定出55种和53种挥发性化合物。基于HS-GC-IMS（RY = 0.998，Q = 0.987）和HS-SPME-GC-MS（RY = 0.984，Q = 0.993）的正交偏最小二乘判别分析模型成功区分了不同储存时间的白茶样品。此外，基于单因素方差分析（p < 0.05）和变量投影重要性（VIP）>1.2的双变量标准筛选出14种和8种关键化合物，并比较了它们的含量变化。正是与甜、果、花香呈正相关的2-己烯醛、2-甲基-2-庚烯-6-酮、芳樟醇和香叶醇等重要香气成分的逐渐减少，以及与草本和陈腐风味呈正相关的己酸、噻吩、丙酸、二甲基二硫醚和乙酸龙脑酯的逐渐增加，导致了白茶在储存过程中风味和香气的变化。该研究结果为阐明不同储存时间白茶的香气特征提供了参考，也为白茶的质量控制提供了理论依据。
