JOURNAL OF FOOD PROCESSING AND PRESERVATION
·
2021
·Vol. 45
·期 10
·e15844
·
IF 2.19
Xiaofen Wu,Tetsuo Ozawa,Yinhua Li,Jihua Duan,Kun Zhu,Jianan Huang,Zhonghua Liu,Keqin Wang
This study evaluated the effects of fermentation time and temperature on the content of high molecular weight polyphenol mitochondrial activation factors (MAFs) and other polyphenols in Congou black tea using high-performance liquid chromatography (HPLC). There were two broad chromatographic peaks in the HPLC spectra of MAFs: MAFs-1 (16.163 min) and MAFs-2 (34.31 min); MAFs-2 was satisfactorily analyzed by HPLC, with separation by paper chromatography. The MAFs-2 contents increased gradually in different varieties of Congou black tea as the fermentation time and temperature increased; the maximum MAFs-2 content was 5.11% in Xiaoxianghong 21-3 after 8 hr of fermentation. The total polyphenols and catechins contents decreased, whereas the theabrownins contents increased as the fermentation time and temperature increased; the theaflavins and thearubigins contents in different Congou black teas showed different variation tendencies. Therefore, studies regarding changes in polyphenols during fermentation will help improve the quality of Congou black tea and enhance its health benefits. Novelty impact statement A new method for the determination of MAFs-2 by high-performance liquid chromatography combined with paper chromatography was established. The content of MAFs-2 increased initially and then stabilized as fermentation was continued from 2 to 8 hr, it increased gradually as the fermentation temperature was increased from 23 to 37°C. These results provide a new analytical method for MAFs in black tea and a theoretical basis and technical guidance for improving the quality of Congou black tea.
研究领域:
食品科学
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分析化学
·
茶叶科学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Qing-Qing Cao,Yan-Qing Fu,Yu-Yi Liu,Yumei Qin,Jian-Xin Chen,Jun-Feng Yin,Yong-Quan Xu
Oral processing (OP), referring to the whole process of food digestion in human mouth, has a major influence on food flavor perception. This study focused on the compositional changes of the four green tea epicatechins (viz., EC, EGC, ECG, EGCG) during OP, based on targeted and nontargeted metabolomics. It was found that the four epicatechins were all extensively lost through transformation undergoing OP, among which EC was the most stable one, whereas EGCG the least. EGCG was further revealed to be susceptible to human oral cavity in the simulated OP in vitro . It could be converted physically by precipitating with mucin in saliva, and chemically through hydrolysis and dimerization, mediated mainly by the neutral pH condition. The OP of epicatechins also caused salivary composition changes possibly involving health benefits of green tea. These findings could raise awareness of the interactions between epicatechins, or any other food materials, with human mouth.
研究领域:
食品科学
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代谢组学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2019
·
IF 3.571
Yinyin Liao,Zhenming Yu,Xiaoyu Liu,Lanting Zeng,Sihua Cheng,Jianlong Li,Jinchi Tang,Ziyin Yang
Insect attack is known to induce a high accumulation of volatile metabolites in tea (Camellia sinensis). However, little information is available concerning the effect of insect attack on tea quality-related nonvolatile specialized metabolites. This study aimed to investigate the formation of characteristic nonvolatile specialized metabolites in tea leaves in response to attack by major tea insects, namely, tea green leafhoppers and tea geometrids, and determine the possible involvement of phytohormones in metabolite formation resulting from insect attack. Both tea green leafhopper and tea geometrid attacks increased the jasmonic acid and salicylic acid contents. The abscisic acid content was only increased under tea green leafhopper attack, perhaps due to special continuous piercing–sucking wounding. Tea green leafhopper attack induced the formation of theaflavins from catechins under the action of polyphenol oxidase, while tea geometrid attack increased the l-theanine content. Exogenous phytohormone treatments can affect the caffeine and catechin contents. These results will help to determine the influence of major tea pest insects on important tea quality-related metabolites and enhance understanding of the relationship of phytohormones and quality-related nonvolatile metabolite formation in tea exposed to tea pest insect attacks.
研究领域:
植物科学
·
农学
·
植物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Food Measurement and Characterization
·
2024
·
IF 2.9
Pang Wanyu,Gao Yali,Chang Xile,Hu Tuoping,Hu Zhiyong,Ma Xuemei
An electrochemical sensing platform based on in-situ acetylene black (AB) template growth ZIF-8 for trace catechin detection in green tea was proposed. Here, the ZIF-8/AB/carbon paper (CP) electrode was constructed by two-step in-situ growth method and hydrothermal method. The characterization showed that AB molecule was well distributed in ZIF-8 pore with large surface area. ZIF-8/AB/CP electrode showed good electrochemical performance for catechin detection, which benefited from the ZIF-8 with larger surface and AB with excellent conductivity. The results showed that ZIF-8/AB/CP electrode was linear in the range of 0.01–200 µM, and the low detection limit for catechin detection was 43.7 nM. ZIF-8/AB/CP also had good reproducibility, anti-interference ability and stability. In addition, the sensor achieved hight-recovery and accuracy in detecting catechin in green tea. As far as we know, our work first reported that ZIF-8/AB composite was synthesized by in-situ growth method as an electrochemical sensing material for the detection of catechin in green tea, which will provide some theoretical analysis and experimental experience for designing and developing electrochemical sensor for the analysis of trace catechin.
研究领域:
分析化学
·
材料科学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
Food Chemistry-X
·
2024
·
IF 6.5
Maiquan Li,Yunxia Dong,Mangjun Kang,Tiantian Tao,Wenlan Li,Sheng Zhang,Wei Quan,Zhonghua Liu
Hyperglycemia can cause early damage to human bady and develop into diabates that will severely threaten human healthy. The effectively clinical treatment of hyperglycemiais is by inhibiting the activity of α-amylase. Black tea has been reported to show inhibitory effect on α-amylase and can be used for hyperglycemia treatment. However, the mechanism underlying is unclear. In this study, in vivo experiment showed that black tea theaflavins extract (BTE) effectively alleviated hyperglycemia. In vitro experiment showed that the effects may be caused by the interation between theaflavins and α-amylase. While TF1 and TF3 were mixed type inhibitors of α-amylase, TF2A and TF2B were competitive inhibitors of α-amylase. Molecular docking analysis showed that theaflavins monomers interacted with the hydrophobic region of α-amylase. Further study verified that monomer-α-amylase complex was spontaneously formed depending on hydrophobic interactions. Taken together, theaflavins showed potential anti-hyperglycemia effect via inhibiting α-amylase activity. Our results suggested that theaflavins might be utilized as a new type of α-amylase inhibitor to prevent and cure hyperglycemia.
研究领域:
营养学
·
药理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2025
·Vol. 14
·期 6
·941
·
IF 5.1
Wenxue Chen,Jiezhong Zan,Linfeng Yan,Haibo Yuan,Peiqiang Wang,Yongwen Jiang,Hongkai Zhu
Tea blending technology is based on finished tea. Blending fresh leaves during processing has not been proposed and investigated anywhere. This study investigates the impact of blending fresh leaves from different varieties on the flavor quality of black tea. The main taste components, including catechins, theaflavins, and free amino acids, were analyzed using HPLC, while the volatile components were analyzed using GC-MS. The results show that adding freshJinguanyinorJinxuanleaves toFudingdabaican regulate the ratio of esterified to non-esterified catechins, increase the content of theaflavins and amino acids, and positively impact the strength and freshness of the black tea. The sensory evaluation results show that the taste scores of FJG (black tea made from the blend of freshFudingdabaiandJinguanyintea leaves) (92.14 ± 0.41 b) and FJX (black tea made from the blend of freshFudingdabaiandJinxuantea leaves) (93.80 ± 0.19 a) are significantly higher than those ofFudingdabai(90.05 ± 0.31 d),Jinguanyin(86.10 ± 0.45 e), andJinxuan(91.03 ± 0.26 c). Furthermore, adding freshJinguanyinorJinxuanleaves toFudingdabaican also enhance the floral compounds in the black tea, specifically phenylacetaldehyde, linalool, benzyl alcohol, and oxidized linalool (linalool-type pyran), which make important contributions to the floral aroma of the black tea. Conclusions: Blending fresh leaves for processing can enhance the sensory quality of black tea. This work proposes new insights and methods to enhance black tea sensory quality via the blending of fresh tea leaves with different varieties during processing.
研究领域:
食品科学
·
茶叶加工学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2025
·
IF 4.6
Xia Liu,Xinxin Wang,Boya Hu,Yani Pan,Xinyu Feng,Anran Yan,Haowei Guo,Yiliang Wei,Tianyuan Chen,Yiqi Ruan,Yuye Yao,Hesham R. El-Seedi,Wen-Wen Zhou,Ping Chen,Qiang Chu
Focusing on the self-assembly process of black tea infusion nanoparticles helps elucidate the formation mechanism of tea cream. Brewing times ranging from 1 to 10 min were systematically assessed in this study, and the release pattern of the major components of the tea infusion was followed and related to the dynamic changes of the components of the black tea cream. The mean particle size of nanoparticles in the black tea infusion gradually increased with increasing brewing time, reaching a maximum (269.84 ± 11.25 nm) at 300 s. The results showed that soluble sugars were the most abundant substances of the tea cream at 60 s, and the proportion changed very little during the process. Proteins and flavonoids were rapidly incorporated into the tea cream, maintaining a concentration trend in accordance with the tea infusion. The percentages of caffeine, theobromine, gallic acid, and catechins in tea cream showed a sudden decrease at 240 s, followed by a gradual increase. This formation of tea cream is pH-dependent, with aggregation and precipitation at pH 0–7 and increased dissociation at pH 7–11. The findings will facilitate a more profound comprehension of the formation mechanism of black tea cream.
研究领域:
食品科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 33
·21135-21144
·
IF 4.036
Yirong Xia,Wei Ni,Xintong Wang,Yanyan Wang,Ximing Huang
The health benefits of drinking tea stem from it being rich in polyphenols and other physiologically-active substances. Thus, exploring the synergistic effect between polyphenols and a variety of physiologically-active substances can contribute to our understanding of how tea benefits health. In this work, we have studied the interactions between catechin and theanine, exploring the synergetic antioxidant mechanism of the two molecules. Electrochemical characterization results showed that the oxidation peak current of catechin decreased gradually with the concentration of theanine, which is due to theanine spontaneously binding to catechin through intermolecular hydrogen bonds and forming molecular clusters via two hydrogen bonds. The binding constant is 4.75 at room temperature. The molecular clusters reduce the diffusion coefficient of catechin in solution, leading to the slow release of its antioxidant capacity (ability to effectively inhibit free radical oxidation reactions). Density functional theory calculations were also performed and verified the binding behavior. In identifying the synergistic effect between catechin and theanine on the antioxidant capacity of tea, this study adds to our understanding of the efficacy of tea polyphenols.
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2012
·
IF 3.655
Yali Wang,Yu Zhao,K. Andrae-Marobela,H. Okatch,Jianbo Xiao
The crude polysaccharides from tea leaves (TPS) looks like have good antioxidant activities. However, whether or not the antioxidant abilities of crude TPS depend on tea polyphenols in the crude TPS is not understand. Herein, TPS fractions were isolated from crude TPS and their antioxidant activities were compared. The crude TPS showed stronger antioxidant activities than that of TPS fractions. However, EGCG (6.15 μg/mL) significantly enhanced DPPH radical scavenging potential of TPS fractions for each dose. Moreover, EGCG (8.0 μg/mL) significantly improved the reducing power of TPS fractions. EGCG causes a synergistic increase in the antioxidant activities of TPS fractions. The antioxidant activities of dextrans in the absence and presence of EGCG were investigated to illustrate that the antioxidant activities of TPS is similar to dextrans. These results illustrated that TPS fractions hardly exhibited antioxidant activities and tea polyphenols are the major antioxidant in the crude TPS. TPS as food antioxidants is an old woman’s tale.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2023
·
IF 5.2
Xianghui Kong,Weiqi Xu,Kaixin Zhang,Guijie Chen,Xiaoxiong Zeng
Theaflavins (TFs) and theasinensins (TSs) are the key components formed from the enzymatic oxidation of tea catechins , contributing significantly to the biological activities and taste of black and Oolong teas. In this study, we aimed to reveal the catechin conversion and the enzymatic synthesis of TFs and TSs under reaction temperatures and pH values using polyphenol oxidase (PPO) from potato tuber ( Solanum tuberosum L.). The results indicated that different temperatures, pH values and durations had significant effects on the conversion of catechins and the formation of TFs and TSs. During the reaction, the most of catechin substrates was consumed at 60–90 min after reaction initiation, and large amounts of the products TFs (0.04–0.41 mg/mL) and TSs (0.51–1.52 mg/mL) were obtained. The content of TSs was significantly higher and the maximum content of TSs was more than three times that of TFs. Reaction at a lower temperature (20 °C) is suitable for producing dimers, especially for TFs. Higher pH value resulted in higher catechin consumption and higher TSs content, while the maximum of TFs was obtained at pH 5.0. The present results provided a theoretical basis and practical guidance for the targeted processing of tea catechin dimers in vitro .
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Ruiyu Zhu,Zhen Chen,Helin Lv,Yani Pan,Xinyu Feng,Guicai Chen,Weilian Hu,Tianhua Xu,Fangyuan Fan,Shuying Gong,Ping Chen,Qiang Chu
Aged white tea (WT) has promising medicinal potential, but how to accurately identify aged white tea is still a difficult problem. Inspired by tea cream, the relationship between the characteristics of nanoparticles in tea infusion and aging time was studied. The results showed that with the increase of aging time, the particle size of white tea nanoparticles (WTNs) decreased gradually. Microscopic images showed that the surface structure of WTNs was changed in three aspects: the waxy layer, the cuticle layer and the palisade tissue. Additional in vitro modeling demonstrated a strong correlation between nanoparticle size and protein and tea polyphenol content. The correlation between nanoparticle sizes and aging time was further verified in aged Pu’er raw tea. Starting with the tea infusion's nanoparticles, this study showed that the aging time of WT would impact the nanoparticles' properties, offering a unique way to determine the aging period of WT.
研究领域:
植物学
·
食品科学
·
医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Chemistry: Molecular Sciences
·
2022
·
IF 0
Jihong Yang,Hanchen Zhou,Yaqin Liu,Hui Wang,Yujie Xu,Jianqin Huang,Pandeng Lei
Green tea processed from albino tea varieties often has umami taste and fresh aroma. This study identified green teas made from two types of albino tea cultivar, one having the white shoots (called Naibai, NB) and the other having the yellow shoots (called Huangjinya, HJY). Taste compounds analyses showed that galloylated catechins were highly concentrated in HJY green teas, whereas non-galloylated catechins and amino acids were more abundant in NB green teas. CsTA (involved in the catabolism of galloylated catechins) showed high expression in HJY tea shoots, resulting in gallic acid as a precursor for β -glucogallin biosynthesis being abundant in HJY. CsPDX2.1 (responsible for theanine hydrolyzation) had a lower expression level in NB than HJY shoots. Fatty acid–derived volatiles (FADVs), glycosidically bound volatiles (GBVs) and carotenoid–derived volatiles (CDVs) were highly concentrated in HJY green teas, whereas amino acids–derived volatiles were highly concentrated in NB green teas.
研究领域:
农业
·
食品科学
·
植物生物化学
✓ 已验证
产品关联
DOI
PubMed
危险品化学品经营许可证（带存储）