FOOD CHEMISTRY
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2024
·
IF 8.5
Zhilong Hao,Jinyuan Wang,Jiayun Zhuang,Xinyu Feng,Helin Lv,Jiao Feng,Shuping Ye,Weisu Tian,Guanjun Pan,Ping Chen,Hongzheng Lin,Qiang Chu
Shaking, essential in oolong tea production, is becoming an innovative method to impart floral fragrance. Research on shaking primarily concentrates on biological underpinnings, including modifications in gene expression and stress-triggered enzymatic catalysis, and consequent physicochemical properties. Water phase and distribution, reshaped by shaking and affected the biological and physicochemical alterations of tea leaves, is always ignored. This work utilized TEM, LF-NMR, UPLC-QqQ-MS, and GC-TOF-MS to explore physicochemical alterations during shaking. Results revealed shaking induced stomatal opening, water migration from stems to leaf veins, and a reduction in free water, transformed into bound water. Mechanical stimulation disrupted cell microstructures, including vacuoles, chloroplasts, and cell walls, releasing precursors and enzyme substrates. Shaking triggered intracellular physicochemical reactions that decreased polyphenols, amino acids, chlorophyll, and carotenoids, while increasing organic acids and sugars. Also catalyzed the synthesis of aromatic compounds like ( E )-nerolidol, β -ionone epoxide, and α -farnesene, shaping the floral-fruity aroma and mellow taste of tea.
研究领域:
植物学
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食品科学
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茶学
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产品关联
DOI
PubMed
高影响因子
Foods
·
2023
·Vol. 13
·期 1
·42
·
IF 5.2
Kuofei Wang,Yangbo Xiao,Nianci Xie,Hao Xu,Saijun Li,Changwei Liu,Jianan Huang,Shuguang Zhang,Zhonghua Liu,Xia Yin
Shaken Hunan black tea is an innovative Hunan black tea processed by adding shaking to the traditional Hunan black tea. The quality of shaken black tea is influenced by leaf grades of different maturity. In this study, the taste and aroma quality of shaken Hunan black tea processed with different grades were analyzed by sensory evaluation (SP, HPLC, and HS-SPME/GC-MS). The results showed that shaken Hunan black tea processed with one bud and two leaves has the best quality, which has a sweet, mellow, and slightly floral taste, as well as a floral, honey, and sweet aroma. Moreover, caffeine and EGCG were identified as the most important bitter and astringent substances in shaken Hunan black. Combined with the analysis of GC-MS and OAV analysis, geraniol, jasmone, β-myrcene, citral, and trans-β-ocimene might be the most important components that affect the sweet aroma, while methyl jasmonate, indole, and nerolidol were the key components that affect the floral aroma of shaken Hunan black tea. This study lays a foundation for this study of the taste and aroma characteristics of shaken Hunan black tea and guides enterprises to improve shaken black tea processing technology.Keywords:shaken Hunan black tea;leaves grade;taste;aroma;HS-SPME/GC-MS
研究领域:
食品科学
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茶叶研究
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产品关联
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2024
·
IF 7
Dongzhu Huang,Chenyi Sun,Yuhan Wu,Fangling Zheng,Qiqi Yang,Xinmeng Zhang,Qianying Dai,Xiaochun Wan,Qi Chen
This study aimed to investigate the effect of the combination of shaking and various anaerobic treatments on the aroma quality of gabaron oolong tea (GAOT) by chemical and sensory evaluation. The results showed that elevated anaerobic treatment harmed GAOT aroma, emphasizing undesirable attributes such as earthy, fatty, etc. A total of 85 volatiles were identified by gas chromatography-ion mobility spectrometry (GC-IMS), and the relationship between aroma attributes and volatiles were revealed by PLS regression projection and correlation network. Hexanal and octanal at inappropriate concentrations were main causes to the earthy attribute, while nonanal exhibited a potential masking effect against unpleasant attributes. Addition experiments and σ-τ plot analysis verified these associations. Furthermore, observing dynamic patterns of content changes of these three aldehydes in fresh leaves prior to tea thermal processing, providing references for future process optimization. These results provide a new direction for enhancing the quality of GAOT.
研究领域:
食品科学
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茶叶加工学
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化学分析
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Shan Zhang,Jinjie Hua,Linchi Niu,Haibo Yuan,Le Chen,Xujiang Shan,Qianting Zhang,Yuning Feng,Qinghua Zhou,Yongwen Jiang,Jia Li
Shaking-withering is a new technique in black tea manufacturing, which enables promoting aroma quality. Lipids are important tea aroma precursors. However, the lipids metabolism and its contribution to aroma formation of shaking-withering black tea (SBT) remain unknown. Herein, 436 lipids and 45 fatty acid-derived volatiles (FADVs) and their dynamic changes during SBT processing were investigated. Among them, 113 lipids and 29 FADVs (mainly floral/fruity fatty aldehydes and esters) were screened as critical compounds associated with shaking-withering. Key enzymes PLA, LOX and HPL showed enhanced activity/expression in SBT. Degradation of glycerophospholipids, glycoglycerolipids, and fatty acids were annotated as potential lipid metabolism pathways. Particularly, glycoglycerolipids containing 18:2, 18:3 fatty acyls, e.g., MGDG(18:2/18:3), DGDG(18:3/18:3), showed most predominate degradation after shaking and negative correlation with FADVs, and were highlighted as key potential aroma precursors in SBT. These results demonstrated that shaking may trigger greater glycoglycerolipids degradation and FADVs formation, contributing to SBT aroma improvement.
研究领域:
食品科学
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植物代谢
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2025
·
IF 6.2
Xia Yin,Yang-bo Xiao,Kuo-fei Wang,Rong-ji Tian,Ying-ying Shen,Han Tang,Run-long Wang,Shu-guang Zhang,Zhong-hua Liu
Shaking is a critical process for enhancing the aroma quality of black tea, though its molecular regulatory mechanisms remain unclear. Through integrated metabolomics and transcriptomics, we found shaking significantly intensifies floral-honey attributes, with a 30–50 % higher market value than conventional black tea.Stir bar sorptive extraction/gas chromatography-mass spectrometry (SBSE/GC-MS) analysis identified 11 key volatile compounds, including methyl jasmonate, jasmine lactone, indole, and nerolidol，as primary contributors to the characteristic aroma profile. The critical biosynthetic window was determined to be the shaking-to-withering transition phase (W8-W15). Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with transcriptomic analysis revealed that shaking activated lipid hydrolysis mediated by CsPLDα1 and CsGPAT , releasing linoleic acid and α-linolenic acid, which subsequently regulated the synthesis of methyl jasmonate and jasmine lactone through CsLOX-5 , CsOPR3 , and CsJMT . Additionally, the newly discovered CsTSβ1L-1 gene was implicated in potential cooperation with CsTSβ2 for indole biosynthesis regulation, while CsNES-1 and CsNES-5 were established as principal regulators of nerolidol synthesis.These findings collectively elucidate how shaking modulates the lipid, shikimate, and mevalonate pathways to shape black tea aroma, providing concrete molecular targets for industrial optimization of premium floral-honey aroma tea production.
研究领域:
植物学
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植物科学
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食品化学
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分子生物学
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农业生物技术
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产品关联
DOI
高影响因子
Foods
·
2025
·Vol. 14
·期 18
·3159
·
IF 5.1
Changlian Wu,Huang Li,Qingxiu Lin,Zhong Wang,Chengzhe Zhou,Cheng Zhang,Yuqiong Guo
One of the main factors constraining the growth of the tea business is the low use rate of summer tea. To enhance the utilization rate and improve the quality of summer tea, this study innovatively integrated shaking, freezing, and rolling into the traditional processing methods of white tea. Processing parameters were optimized through single-factor experiments combined with an L9(34) orthogonal experimental design. The quality of summer teas was systematically evaluated using sensory analysis, gas chromatography–mass spectrometry, and high-performance liquid chromatography. This study found that the optimal processing for summer tea was as follows: fresh leaves, room-temperature cold-air withering for 6.5 h, shaking at 10 rpm for 10 min, −20 °C freezing for 5 h, 25% strength rolling for 9 min, and drying at 75 °C for 2 h. The relative content of esterified catechins in summer tea produced by the optimal processing method was reduced by 14.62% compared with the control group. There were alterations in the content of amino acid components, with fresh and sweet amino acids increasing by 4.96% and 2.95%, respectively, and bitter amino acids reducing by 2.15%. Furthermore, γ-aminobutyric acid and L-theanine contents increased by 0.51% and 5.77%, respectively. Five characteristic volatile compounds were identified, namely, methyl salicylate, phenethyl formate, linalool, dimethyl sulfide, and isobutyraldehyde. The volatile profile was dominated by floral and fruity notes, except for dimethyl sulfide, which exhibited a distinct cooked corn-like aroma characteristic. This process was shown to improve the quality of summer tea. The results of this study provide a metabolite-level grounds for improving the quality of summer tea.
研究领域:
食品科学与技术
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茶叶加工工程
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植物生物化学
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代谢组学
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产品关联
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2019
·
IF 3.579
Si Chen,Huihui Liu,Xiaoman Zhao,Xinlei Li,Wenna Shan,Xiaxia Wang,Shanshan Wang,Wenquan Yu,Zhenbiao Yang,Xiaomin Yu
Oolong tea is a partially fermented tea with distinct tastes and aromas. However, the dynamic biochemical changes during oolong tea processing are not well understood. In this study, we performed metabolomics-based profiling of non-volatile and volatile constituents of oolong tea during its entire processing procedures by UPLC-QTOF MS and GC-TOF MS. A step-wise change of tea metabolome was observed, where catechins and oxidized products, flavonol glycosides and amino acids were identified as key discriminate metabolites. The ZuoQing process comprising alternating YaoQing and TanQing steps was deemed most critical for key metabolic transformation. Extensive YaoQing facilitated the oxidative polymerizations of catechins into theaflavins and proanthocyanidins, lowering the astringency in raw tea. Two direct terpene precursors farnesyl pyrophosphate and geranyl pyrophosphate accumulated to high levels during ZuoQing, which provided more substrates for the synthesis of downstream volatile terpenes. Moreover, both YaoQing and prolonged TanQing facilitated the formation of terpenes as well as fatty acid and benzenoid-derived volatiles, which contributed to the fruity and floral fragrances in oolong tea. The fixation step not only converted amino acids into aromatic compounds, but also lowered the amounts of flavonol glycosides, potentially improving the flavor quality of the final tea product. This study provides a comprehensive profile of flavor-related metabolic changes during oolong tea processing and will contribute to better quality control and flavor improvement of oolong tea.
研究领域:
食品科学
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农业化学
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植物代谢
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产品关联
DOI
PubMed
高影响因子
Foods
·
2024
·Vol. 13
·期 21
·3456
·
IF 4.7
Yamin Wu,Xinghua Wang,Lijiao Chen,Qiang Li,Junjie He,Xiujuan Deng,Jiayi Xu,Raoqiong Che,Jianyun Zhou,Wenxia Yuan,Tianyu Wu,Juan Tian,Yaping Chen,Baijuan Wang
To explore the effects of different withering methods on the quality of Congou black tea, this study focused on five different withering methods: natural withering, warm-air withering, sun–natural combined withering, sun withering, and shaking withering. Gas chromatography‒mass spectrometry (GC‒MS), high-performance liquid chromatography (HPLC), and ion-exchange chromatography techniques were used to analyze the nonvolatile and volatile components and composition of the tea. The results revealed significant differences (p< 0.05) in the contents of nonvolatile constituents including caffeine, polyphenols, soluble sugars, free amino acids and their components, theaflavins, thearubigins, and catechins among the five different withering methods, with varying degrees of correlation between these components. A total of 227 aroma compounds were detected, and significant differences in the contents of alcohols, aldehydes, and ketones were observed. A relative odor activity value (ROVA) analysis of the aroma compounds revealed that 19 compounds had an ROVA > 1. Among them, benzylaldehyde, trans-2-decenal, decanal, benzaldehyde, nonanal, hexanal, trans-linalool, and geraniol from the shaking withering method had significantly higher ROVA values than those from the other withering methods, which may be the reason for the prominent floral and fruity aroma of shaking withering. This study revealed the impact of different withering methods on the quality of Congou black tea, providing a scientific basis for the development of Congou black tea with different flavors and the improvement of Congou black tea processing techniques.
研究领域:
食品科学
·
农业化学
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茶叶科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）