JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2023
·Vol. 103
·期 12
·6033-6043
·
IF 4.1
Jun-long Mao,Jing-jing Fu,Xue-er Qi,Yue-wen Chen,Bin Zhang
BACKGROUND Large yellow croaker ( Larimichthys crocea ) is an economical marine fish consumed in China. Theaflavins have antibacterial and antioxidant properties. However, there is a lack of research into their application in large yellow croakers during refrigerated storage. This study investigated the effect of theaflavins on the quality of large yellow croaker ( Larimichthys crocea ) during 12 days of storage at 4 °C. RESULTS The results showed that theaflavin treatment was able to inhibit microbial growth and reduce the production of total volatile basic nitrogen (TVB-N). Meanwhile, theaflavins were beneficial in reducing the unfolding of myofibrillar proteins, decreasing the degree of protein aggregation, and improving the stability of protein structure. The degree of protein oxidation was lower in a theaflavin-treated group compared with an untreated group. Theaflavin treatment effectively inhibited increases in acid value (AV), peroxide value (PV), and malonaldehyde (MDA) content. The effect of theaflavin was positively correlated with an increase in concentration under refrigeration conditions. This study therefore suggests that the use of theaflavins is a viable method for extending the period for which refrigerated large yellow croaker can be preserved. CONCLUSIONS Adding theaflavins to large yellow croaker can be an effective method for preserving quality during refrigerated storage. © 2023 Society of Chemical Industry.
研究领域:
食品科学
·
海洋生物学
✓ 已验证
产品关联
DOI
PubMed
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
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2018
·
IF 3.129
Lujing Xu,Guobin Xia,Zisheng Luo,Songbai Liu
In this study, an effective ultra-high performance liquid chromatography (UHPLC) method for simultaneous determination of 15 constituents of catechins, caffeine, gallic acid and theaflavins was developed. Employing the developed UHPLC method, the contents of the 15 constituents were analyzed in 245 samples of 6 types of Chinese teas collected from different places. The catechin contents in these samples ranged from 16.50 to 94.35 mg/g. Theaflavins were not detected in green tea and white tea, and caffeine did not strongly relate to germplasm resource or fermentation degree. Principal component analysis (PCA) of UHPLC data revealed that white, oolong and green tea samples could be clustered closely, demonstrating notable difference of functional components between the three types of teas resulting from preparation process and varieties. The constituent profile could be primarily attributed to the structural transformation of catechins and pigments during tea processing. This study would advance our understanding of chemical profile of Chinese teas afforded by different processing technologies.
研究领域:
食品科学
·
分析化学
·
植物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2024
·
IF 4
Yujie Ai,Qidi Wu,Haibo Yuan,Yingqin He,Yongwen Jiang,Suzhen Niu
Catechins and theaflavins , as the primary bioactive constituents of black tea, have a significant impact on its color, aroma, and flavor profile. We developed a rapid and precise method using HPLC to detect catechins and theaflavins in black tea. The method employed 0.1% formic acid-acetonitrile (phase A) and 1% formic acid-water (phase B) as mobile phases . Separation occurred on an Agilent SB-C18 column (4.6 mm × 250 mm, 5 µm), with 20 μL injection volume. Detection took place at 30 °C with a flow rate of 1 mL/min for 55 min.Quantitative determination utilized the external standard method, exhibiting high sensitivity (limit of detection: 0.19 to 5.14 μg/mL) and a strong linear correlation (R2 ≥ 0.9993) between concentration range and peak area. Precision, repeatability, and stability were excellent, with relative standard deviations (RSDs) below 5% (n = 5). The average recovery rate of standard addition ranged from 98.02% to 102.57%, with an RSD of less than 3.17% (n = 5). In summary, this straightforward, efficient, and precise approach is well-suited for both qualitative and quantitative analysis of catechins and theaflavins in tea. It overcomes the limitations of previous methods, providing a valuable tool for evaluating the quality and composition of black tea.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2021
·
IF 6.475
Cheng Guo,Jing Li,Yijie Chen,Fang Geng,Bin Li
Epigallocatechin gallate (EGCg) and methylxanthines are representative bioactive compounds in tea leaves, the strong affinity between them will elicit destruction of tea quality. In order to elucidate the mechanism of complexation between EGCg and methylxanthines, we compared the bindings of theophylline and caffeine to EGCg by nuclear magnetic resonance (NMR), molecular docking and isothermal titration calorimetry (ITC). The results revealed that the stoichiometries of caffeine to EGCg and theophylline to EGCg were both 1:1. Caffeine and theophylline were captured in the hydrophobic space formed by aromatic rings of EGCg. The affinity between EGCg and caffeine was stronger than that between EGCg and theophylline, which could be partially attributed to the two extra CH-π interactions between N 7 -Me of caffeine and aromatic rings of EGCg. Furthermore, the results of ITC were agreed well with NMR and molecular docking, indicating that ITC was possible to accurately evaluate the complexation.
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
PROCESS BIOCHEMISTRY
·
2020
·
IF 2.952
Jianmin Chen,Qinglian Li,Yaling Ye,Mengnan Ran,Zhipeng Ruan,Nan Jin
Xanthine oxidase (XO) catalyzes the oxidation of hypoxanthine to xanthine and then to uric acid. Excessive production of uric acid leads to hyperuricaemia. Due to the serious side effects of allopurinol, it is an urgent need to explore new XO inhibitors. Herein, the effects of theaflavin (TF1) on XO and anti-hyperuricaemia effect in hyperuricemic mice were investigated. Kinetic analysis indicate that TF1 is a reversible competitive inhibitor and has a significant inhibitory effect on XO with an IC 50 value of 63.17 ± 0.13 μmol/L. Analysis of fluorescence spectra suggests that TF1 causes the obvious fluorescence quenching of XO, which is mainly driven by hydrophobic interactions and hydrogen bonds. Docking studies demonstrate that TF1 interacts with dozens of amino acid residues surrounded in the active cavity of XO, including Glu-879, Pro-1012, Thr-1010, Val-1011, Lys-771, Glu-802, Pro-1076, Leu-873, Leu-1014, Asn-768, Leu-648 and Phe-649. The inhibitory mechanism may be the insertion of TF1 into the active site of XO, which hinders the substrate xanthine to enter into the site. Furthermore, the results from animal experiments demonstrate that TF1 is effective in reducing serum uric acid in mice. These findings suggest that TF1 may be a potential drug candidate for the treatment of hyperuricaemia.
研究领域:
药理学
·
生物化学
✓ 已验证
DOI
高影响因子
JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
·
2017
·Vol. 54
·期 11
·3421-3432
·
IF 1.262
Lei Shicheng,Xu Donglan,Saeeduddin Muhammad,Riaz Asad,Zeng Xiaoxiong
In this study, theaflavins (TF1, TF2A, TF2B and TF3) were prepared from black tea and their interaction with bovine serum albumin (BSA) was explored by fluorescence and CD spectroscopy. The results showed that the structures of theaflavins exhibited significant effects on the binding/quenching process, and the binding affinity increased with the increase of molecular weight of theaflavins and the presence of galloyl moiety. The quenching effects showed a sequence as TF3 > TF2A > TF2B > TF1, demonstrating the important role of the galloyl moiety on the C-3 position of theaflavins. CD spectra indicated that TF3 in high concentration could change the skeleton structure of BSA and induce the unfolding of BSA secondary structure. The present results provide a new perspective for better understanding of the likely physiological fate of theaflavins and help to control the functional characteristics of food.
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
·
2019
·Vol. 55
·期 4
·1531-1538
·
IF 2.281
Yangping Ding,Bingcan Chen,Huayi Suo,Huarong Tong
Summary Theaflavin-3,3′-digallate (TFDG) is the main product formed by oxidative condensation between (−)-Epigallocatechin-3-gallate (EGCG) and (−)-Epicatechin-3-gallate (ECG). Some sub-products, such as homo- and hetero-oligomers of EGCG and ECG, are also produced simultaneously, which significantly decreases the yield of TFDG. In general, the optimum temperature for TFDG synthesis is 20 °C below which can reduce its generation resulting in the coexistence of a large amount of unreacted substrates (ECG and EGCG). Therefore, a higher possibility of increasing the formation of TFDG could be achieved if a suitable synthetic method can be developed at a low temperature. Our results showed that simultaneous dropwise addition of both EGCG and ECG could markedly enhance the content of TFDG at ice bath. Using such technique, the production of TFDG increased by 47.60% as compared to the group synthesised under the optimum temperature. The absorbance of TFDG at 278 nm is 2.36 times higher than that of ECG with equimolar concentration. Therefore, a rapid, simple and accurate calculation method of TFDG yield was developed via the spectral correlation. Based on the counting method, the yield of TFDG was 30.58% by using the novel synthetic method of TFDG.
研究领域:
食品科学
·
植物化学
✓ 已验证
DOI
高影响因子
Food Packaging and Shelf Life
·
2022
·
IF 8.749
Long Jiao,Chuanhai Tu,Junlong Mao,Soottawat Benjakul,Bin Zhang
The effect of theaflavin pretreatment on changes in quality of semi-dried large yellow croaker fillets was investigated and compared with a water-soaking treatment during storage. The data indicated that the springiness, chewiness , L *, and b * values of the control and theaflavin-treated fillets both showed significantly decreasing trends during 5 days of room-temperature and 40 days of chilled storage. However, the incorporation of theaflavins exhibited positive effects on the texture and color stability of the fillet samples. Importantly, the antioxidant theaflavin treatment significantly inhibited the rapid increase of the TVBN content, reduced the peroxide and thiobarbituric acid index values, and slowed the changes in the myofibrillar carbonyls and surface hydrophobicity during storage when compared with those of the water-soaking treatment. Additionally, histological observations verified that the theaflavins showed pronounced effects on the stability of myofibrillar proteins (MPs) and remarkably inhibited MP and lipid oxidation during the two types of storage.
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2016
·
IF 3.138
Shicheng Lei,Minhao Xie,Bing Hu,Li Zhou,Yi Sun,Muhammad Saeeduddin,Hongcheng Zhang,Xiaoxiong Zeng
In the present study, pear polyphenol oxidase (PPO) was purified, immobilized and applied for the synthesis of theaflavin-3,3′-digallate (TF3). Firstly, PPO of pear ( Pyrus bretschneideri Rehd cv. Huangguan) was purified 24.36-fold in specific activity with a recovery of 6.77% by sequential use of precipitation with 70% saturated ammonium sulfate and chromatography of DEAE-Sepharose Fast Flow column. The purified pear PPO, found to be a dimer of identical subunits of molecular mass 35 kDa, was then successfully immobilized onto Fe 3 O 4 /chitosan nanoparticles via glutaraldehyde coupling reaction. Finally, TF3 was effectively synthesized by applying the immobilized PPO as biocatalyst with epicatechin gallate (ECG) and epigallocatechin-3- O -gallate (EGCG) as substrates, and the maximum yield of TF3 was 42.23% based on the amount of ECG added. In addition, the immobilized enzyme still remained 85% of its initial ability after successive usage of 8 cycles and could be stored for 30 days with less loss of activity. All the results suggest that the developed procedure is quite useful and has great potential for synthesis of TF3 and other theaflavins.
研究领域:
食品科学
·
酶工程
·
植物学
✓ 已验证
DOI
PubMed
高影响因子
BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
·
2021
·Vol. 69
·期 3
·951-962
·
IF 2.431
Jianmin Chen,Mengnan Ran,Meixia Wang,Xinying Liu,Siwan Liu,Zhipeng Ruan,Nan Jin
Tyrosinase is a key metalloenzyme for the biosynthesis of melanin that plays a critical role in the prevention of skin damage caused by ultraviolet (UV) radiation. However, the overproduction of melanin may cause a variety of skin diseases. Due to the toxicity and inefficiency of existing tyrosinase inhibitors, it is urgent to identify safe and potent alternatives from natural sources. Theaflavin, a single-component extracted from black tea, has been found to possess a variety of pharmacological activities. Herein, the inhibition kinetics of theaflavin on tyrosinase and inhibitory mechanism were determined using spectroscopy, molecular docking, and zebrafish model. The results showed that theaflavin inhibited the diphenolase activity of tyrosinase in a reversible mixed type manner with IC 50 of 229.75 μmol/L and hindered the synthesis of melanin in zebrafish. This may be due to the formation of eight hydrogen bonds and hydrophobic effects between theaflavin and tyrosinase according to the results of molecular docking. To study the possible effects on the prevention of free radical-mediated skin cancer and photoaging caused by UV radiation, the antioxidation and UV filter properties of theaflavin were further verified. This study demonstrates that theaflavin is a potential multifunctional compound that can be used in cosmetic and medicinal products.
研究领域:
生物化学
·
药理学
·
皮肤科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Mengting Wang,Wenwen Guo,Zhijian Ke,Haiguang Mao,Jimin Lv,Lili Qi,Jinbo Wang
Theaflavins, oxidation product of tea polyphenols, have demonstrated significant inhibitory effects on α-glucosidase, which is beneficial in alleviating hyperglycemia. This study found that the inhibition of four monomers of theaflavins on α-glucosidase was related to the presence of the galloyl moiety (GM), with IC 50 values ranging from TFDG (0.26 mg/mL) < TF3′G (0.33 mg/mL) < TF3G (0.39 mg/mL) ≪ TF (3.26 mg/mL). The multi-spectroscopic analyses revealed that theaflavin monomers changed the microenvironment around aromatic amino acid residues and conformation of α-glucosidase, with the hierarchy being TFDG > TF3′G > TF3G > TF. The binding of theaflavins with α-glucosidase was confirmed by differential scanning calorimetry (DSC), isothermal titration calorimetry (ITC), molecular docking and molecular dynamics simulations analysis. It was confirmed that theaflavins can form stable complexes with α-glucosidase, and that hydrogen bonding and van der Waals forces play important roles in the binding of theaflavins to α-glucosidase. The strongest binding affinity was observed between TFDG and the enzyme's active site, which corresponded with its enzyme activity inhibition ability. The study suggests that GM substitution plays a crucial role in enhancing the binding of theaflavins to α-glucosidase, thereby inducing greater conformational changes and leading to a stronger inhibitory effect on α-glucosidase.
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
危险品化学品经营许可证（带存储）