Article
Food Science & Technology
Yahan Zhou, Fan Luo, Xuejiao Gong, Dongna Liu, Lanying Li, Yu Yao, Chunyan Fang, Yulong Ye
Summary: Withering is a necessary step to enhance the flavor of black tea. In this study, the morphological changes during withering and dynamic changes in proteinaceous amino acids were investigated. The results showed that tea leaves gradually withered, shrunk, and darkened in color. Umami amino acids remained at higher levels throughout the withering process, while sweet and bitter amino acids exhibited a cumulative effect in the middle and late stages of withering. Several driving proteins involved in the metabolic regulation of specific amino acids were identified. Functional analysis revealed that tea leaf cells maintained high cellular activity during withering and toxins were decomposed at the end. These findings provide a metabolic basis for room temperature withering to improve the quality of black tea.
LWT-FOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Food Science & Technology
Yuchuan Li, Chang He, Xinlei Yu, Jingtao Zhou, Bernard Ntezimana, Zhi Yu, Yuqiong Chen, Dejiang Ni
Summary: Research has shown that red-light withering (RLW) can enhance the floral aroma of summer-autumn black tea by increasing the content of main floral aroma components. RLW significantly up-regulates the expression of terpene synthesis-related genes in the late withering stage, promoting the synthesis of volatile terpenoids and improving the aroma quality of black tea. Additionally, RLW can increase glycosidase activity in the later withering stage, contributing to the enhancement of aroma in black tea processing.
LWT-FOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Food Science & Technology
Bernard Ntezimana, Yuchuan Li, Chang He, Xinlei Yu, Jingtao Zhou, Yuqiong Chen, Zhi Yu, Dejiang Ni
Summary: The study found that withering time between 8±0.5 hours and 10±0.5 hours can improve the quality and nutritional characteristics of black tea.
Article
Food Science & Technology
Yahui Wang, Chenxue Li, Jiaqi Lin, Yun Sun, Shu Wei, Liangyu Wu
Summary: This study conducted complementary metabolomic and proteomic analyses on solar- and indoor-withered oolong tea leaves to elucidate the mechanisms underlying the formation of flavor determinants during the early stage of oolong tea processing. The analysis identified a total of 978 non-volatile compounds and 152 volatile compounds, with differential accumulation of flavonoids and esters in different tea samples. Pathway enrichment analysis revealed that phenylpropanoid and flavonoid metabolisms, as well as protein processing in the endoplasmic reticulum, were the major pathways distinguishing the tea samples. The joint protein-metabolite analysis showed dynamic and distinct changes in the biochemical network induced by multiple stresses during the withering step, leading to decreases in flavonoids and amino acids. Furthermore, fruity and floral aromas, especially volatile terpenoids and phenylpropanoids/benzenoids, were retained or accumulated in the solar withered leaves, potentially contributing to the characteristic flavor of oolong tea made by indoor withered leaves.
Article
Food Science & Technology
Yingqing Ye, Jiazheng Lin, Junfeng Yin, Hua-Feng He
Summary: Fermentation is crucial for black tea production. The ratio of ss-cyclocitral to.-pylpyrone was found to be positively correlated with the sensory score of black tea. Metabolomics analysis revealed significant metabolic differences during fermentation, providing valuable insights for the intelligent modulation of black tea production.
FOOD RESEARCH INTERNATIONAL
(2023)
Article
Food Science & Technology
Yuchuan Li, Chang He, Xinlei Yu, Jingtao Zhou, Wei Ran, Yuqiong Chen, Dejiang Ni
Summary: Red-light withering can significantly improve the taste quality of summer-autumn black tea by increasing the content of amino acids and theaflavins. RLW can also impact the protein-amino acid content in tea leaves and promote the formation of partial catechins.
LWT-FOOD SCIENCE AND TECHNOLOGY
(2021)
Article
Food Science & Technology
Li Zhu, Siyu He, Ying Lu, Jianhong Gan, Ningping Tao, Xichang Wang, Zaoli Jiang, Yuanxiang Hong, Changhua Xu
Summary: This study comprehensively investigated the changes in metabolic compounds of Chinese traditional fermented soy sauce (CTFSS) associated with fermentation time. The results showed significant changes in formaldehyde nitrogen, total soluble nitrogen, non-salt soluble solids, amino acids, free 5'-nucleotides, and volatile compounds. The study also revealed an opposite trend between volatile compounds and amino acids, indicating a transformation between these two components.
FOOD SCIENCE AND HUMAN WELLNESS
(2022)
Article
Food Science & Technology
Huiting Wu, Yuyu Chen, Wanzhen Feng, Shanshan Shen, Yuming Wei, Huiyan Jia, Yujie Wang, Weiwei Deng, Jingming Ning
Summary: This study investigated the effects of different withering treatments on the aroma of white tea. The results showed that white tea withered under sunlight had a more obvious flower aroma, while white tea withered in a withering-tank had a more pronounced grassy aroma. Various volatile compounds were detected, and nine key odorants were identified to be responsible for the floral and grassy aromas.
Article
Food Science & Technology
Huajie Wang, Shuai Shen, Jinjin Wang, Yongwen Jiang, Jia Li, Yanqin Yang, Jinjie Hua, Haibo Yuan
Summary: The study found that 3 hours was the optimal fermentation time for retaining key compounds such as simple catechins, promoting the formation of TFs and TRs, facilitating sugar formation and conversion, and degrading flavonoid glycosides. At this time, volatile compounds were most abundant, and the samples had the best sensory quality.
LWT-FOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Food Science & Technology
Li Zou, Shanshan Shen, Yuming Wei, Huiyan Jia, Tiehan Li, Xuchao Yin, Chengye Lu, Qingqing Cui, Fan He, Weiwei Deng, Jingming Ning
Summary: This study investigated the effect of solar withering (SW) on the quality of white tea using metabolomics and transcriptomics. SW increased the bitterness and astringency of white tea and significantly increased the concentration of astringent flavonoids and flavone glycosides. In addition, SW caused heat and light stress, leading to increased levels of glycerophosphatidylcholine and carbohydrates, which affected the taste of white tea.
FOOD RESEARCH INTERNATIONAL
(2022)
Article
Agriculture, Multidisciplinary
Weixin Wang, Christina Ohland, Christian Jobin, Shengmin Sang
Summary: This study investigates the chemical structures and mechanisms underlying the health benefits of thearubigins, the polymers of tea catechins. The researchers found that thearubigins can be metabolized by gut microbiota into smaller molecular metabolites such as theaflavins and theasinensins, which are the building units for the complex thearubigins. These findings provide insights into the bioavailability and metabolism of thearubigins.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2022)
Article
Chemistry, Applied
Binxing Zhou, Zihao Wang, Peng Yin, Bingsong Ma, Cunqiang Ma, Chengcheng Xu, Jiacai Wang, Ziyu Wang, Dingfang Yin, Tao Xia
Summary: In this study, 20 bioactive compounds in 12 teas from Xinyang Region were analyzed using high performance liquid chromatography, with antioxidant activities measured and metabolomics analysis conducted. The teas were successfully differentiated into green and white teas based on their chemical composition, with white tea showing higher antioxidant activity and distinct metabolite profiles compared to green tea.
Article
Food Science & Technology
Biying Zhu, Jing Zhang, Junyao Li, Shimao Fang, Zheng-Zhu Zhang, Rangjian Wang, Wei-Wei Deng
Summary: This study compared the aroma characteristics and volatile compounds of JM tea and TY tea using sensory evaluation and chemical analysis. The results showed significant differences in volatile compounds between teas from different sources, which helps to further understand the characteristics of JM tea.
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
(2021)
Article
Food Science & Technology
Huajie Wang, Jinjin Wang, Haibo Yuan, Shuai Shen, Jia Li, Jinjie Hua, Yongwen Jiang
Summary: Appropriate withering degree has a positive impact on the quality of Dianhong Congou black tea by promoting the conversion of catechins, degrading flavonoid glycosides, and forming and converting soluble sugars and high-boiling volatile compounds. It also enhances the color attributes and sensory qualities of the tea.
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Agriculture, Multidisciplinary
Dan Chen, Yanni Zhao, Jiakun Peng, Yue Zhang, Jianjian Gao, Wenliang Wu, Dongchao Xie, Zhengyan Hu, Zhi Lin, Weidong Dai
Summary: This study investigated the dynamic changes in compounds in black teas stored for a period of time, revealing that some compounds decrease while others increase during storage. Additionally, new compounds called N-ethyl-2-pyrrolidinone-substituted TFs were discovered for the first time in tea during the study.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Gaozhen Liang, Chunwang Dong, Bin Hu, Hongkai Zhu, Haibo Yuan, Yongwen Jiang, Guoshuang Hao
SCIENTIFIC REPORTS
(2018)
Article
Chemistry, Applied
Hongkai Zhu, Mahesha M. Poojary, Mogens L. Andersen, Marianne N. Lund
Article
Engineering, Chemical
Hongkai Zhu, Fei Liu, Yang Ye, Lin Chen, Jingyuan Li, Anhui Gu, Jianqiang Zhang, Chunwang Dong
JOURNAL OF FOOD ENGINEERING
(2019)
Article
Chemistry, Applied
Wei Zhang, Beibei Zhang, Yang Ye, Hongkai Zhu
Article
Food Science & Technology
Lin Chen, Fei Liu, Yunfei Yang, Zheng Tu, Jiazheng Lin, Yang Ye, Ping Xu
Summary: The study found that increasing oxygen concentrations can improve the taste of black tea by reducing astringency and bitterness while enhancing umami intensity. Oxygen-enriched fermentation also promotes the oxidation of catechins, flavonoid glycosides, and some phenolic acids, leading to the degradation of amino acids and formation of volatile aldehydes.
FOOD RESEARCH INTERNATIONAL
(2021)
Article
Agriculture, Multidisciplinary
Hongkai Zhu, Feiyang Chu, Jingyuan Liu, Lin Chen, Yang Ye
Summary: This study investigated the effects of particle size on the composition, physical, rheological, and bioactive properties of black tea powder. The results showed that larger particle sizes had higher bulk density and flowability, while smaller particle sizes had good swelling ability and wettability. The contents of water extract, total polyphenols, crude fiber, catechins, and thearubigins decreased with a decrease in particle size. Changing the particle size and concentration could adjust the elastic modulus and viscous modulus of the black tea powder suspension. Moreover, black tea powder with smaller particle size could regulate blood lipids in a hyperlipidemic rat model, while larger particles had an advantage in reducing body weight.
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
(2022)
Article
Agriculture, Multidisciplinary
Fei Liu, Zheng Tu, Lin Chen, Jiazheng Lin, Hongkai Zhu, Yang Ye
Summary: This study systematically investigated the dynamic changes in chemicals in green tea during roasting using non-targeted metabolomics. The results revealed that glycosylation, oxidative polymerization, and pyrolysis were important reactions responsible for the formation and transformation of flavor compounds in roasted green tea during roasting.
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
(2023)
Article
Food Science & Technology
Jiazheng Lin, Yuwan Wang, Lin Chen, Yunfei Yang, Zheng Tu, Yang Ye
Summary: This study investigated the influence of stem presence on the flavor substances and aroma of oolong tea using electronic tongue, sensory evaluation method combined with liquid chromatography, and gas chromatography-mass spectrometry. The results showed that stems significantly increased the umami taste and the content of certain amino acids, as well as nerolidol in aroma components.
Article
Food Science & Technology
Fei Liu, Yun Wang, Harold Corke, Hongkai Zhu
Summary: This study comprehensively characterized the dynamic changes of flavonoids during black tea processing using UPLC-MS/MS. It identified 203 flavonoids during the process, showing a significant increase in flavones, flavonols, and flavonoid polymers during withering, while over 80% of flavonoids decreased during fermentation. The hydrolysis of flavonoid glycosides mainly occurred during rolling, and the variation of flavonoids in the drying stage depended on their thermal stability.
LWT-FOOD SCIENCE AND TECHNOLOGY
(2022)
Article
Environmental Sciences
Haolin Yu, Guangjie Fang, Kenneth A. Rose, Jiazheng Lin, Jie Feng, Haiyan Wang, Qingxian Cao, Yanli Tang, Tao Zhang
Summary: This research investigates the effects of hypoxia on organisms in complex habitats and the influence of highly preferred artificial reefs on their exposure to low dissolved oxygen (DO) levels. Results show that lower DO levels decrease the usage of preferred habitats for sea cucumbers and habitat-generalist fish, but increase the affinity for preferred habitats in habitat-specific fish. The availability of artificial reefs affects the exposure to low DO levels for habitat-preferring fish, but not for habitat-generalist fish.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Horticulture
Jiazheng Lin, Zheng Tu, Hongkai Zhu, Lin Chen, Yuwan Wang, Yunfei Yang, Haowei Lv, Yan Zhu, Liaoyuan Yu, Yang Ye
Summary: Combined withering and shaking processes were evaluated for their effect on volatile compounds and aroma formation in black tea. The study found that withering-shaking produced a fruitier tea, while shaking-withering produced a more floral tea. This research provides a theoretical basis and technical guidance for the production of black teas with different floral-fruity aroma biases.
Article
Food Science & Technology
Hongkai Zhu, Jianqiang Zhang, Fei Liu, Lin Chen, Yang Ye
Summary: The method of rehydration with freeze-drying (RFD) can improve the appearance of roasted green tea by changing its color from dark green to bright green and altering the pigment contents. Additionally, there are optimum parameters to follow during the rehydration process.
FOOD QUALITY AND SAFETY
(2021)
