INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Jun Zeng,Gang Du,Xue Shao,Ke-Na Feng,Ying Zeng
Theaflavins (TFs) have attracted much attention due to their various bioactivities in black tea. This paper describes the first trial for enzymatic production of TFs by recombinant polyphenol oxidases (PPOs). PPO genes were cloned from nine species and expressed in E. coli . Crude enzyme assays by LC-MS revealed that eight recombinant PPOs were active for TFs production from tea polyphenols as substrates. Much higher activities were observed for crude enzymes of Md2 from Malus domestica (apple), Pp4 from Pyrus pashia (pear), and Ej2 from Eriobotrya japonica (loquat). When immobilized on mesoporous silica, crude Md2 was most active. The purified Md2 was immobilized and showed almost twice activity as high as its free enzyme. While the maximum activity of free enzyme was found at pH 5 and 10–30 °C, the immobilized enzyme had broader range of pH 4–6 and 10–40 °C. The activity of immobilized enzyme was relatively constant during the pH and thermal stability test. When used at 0.2 mg/ml in the beginning, the immobilized enzyme retained approximately 40% of its initial activity after 8 cycles of operation.
研究领域:
生物技术
·
酶学
·
食品科学
·
植物生化
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Hai-Biao Gong,Yue Ye,Shuo-Yan Tan,Qi Wang,Xiao-Yuan Gu,Chang-Yu Yan,Yu-Fei Wang,Yi-Ning Chen,Shi-Sheng Chen,Jian-Wen Ye,Wan-Yang Sun,Wei-Xi Li,Kun Li,Jing-Hao Wang,Hiroshi Kurihara,Yi-Fang Li,Rong-Rong He
Despite the known benefits of tea (Camellia sinensis), the functional potential of tea-derived proteins remains largely unexplored. To investigate this, tea proteins were extracted and enzymatically hydrolyzed with alkaline protease to obtain tea protein hydrolysates (TPH). Characterized by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), TPH were screened via integrated in silico and molecular docking for dual-action peptides targeting tyrosinase inhibition and antioxidant activity. Two peptides, EGFG and FGDPHG, were identified and validated as potential tyrosinase inhibitors and antioxidants, exhibiting strong free radical scavenging and iron-chelating capabilities in cell-free systems. In B16-F10 melanoma cells, both peptides significantly reduced α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis and protected against hydrogen peroxide (H2O2)-induced oxidative stress. Their whitening efficacy was further confirmed in a zebrafish model. These findings establish EGFG and FGDPHG as novel, dual-action whitening peptides, highlighting their potential as functional ingredients in cosmetics and nutraceuticals.
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DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2019
·Vol. 7
·期 39
·5972-5982
·
IF 5.047
Xue Jiang,Yu Sun,Lihuang Shang,Conglian Yang,Li Kong,Zhiping Zhang
“Green chemistry” is a newly developed approach that uses natural products to fabricate drug delivery systems; it has many advantages, such as low cost, simplicity, rapidity and environmental friendliness. In this study, we fabricated doxorubicin-loaded gold nanoclusters via a “green chemistry” method, involving the use of green tea extract to realize combinational photothermal and chemotherapy against melanoma. Green tea extract acted as a reducing agent of chloroauric acid and a stabilizer of the nanoclusters, and it also provided a co-polymerization site for doxorubicin. Gold nanoclusters were formed in the presence of the reductive polyphenols in the green tea extract. The accordingly converted polyphenol oxides could assemble into oligomers to stabilize the formulated nanoclusters while co-polymerizing with doxorubicin through π–π stacking and electrostatic interactions. This drug delivery system showed good stability, pH-sensitive drug release properties and enhanced cellular uptake. In vitro and in vivo experiments both demonstrated that our system with combinational photothermal and chemotherapy could achieve significantly enhanced tumor growth inhibition compared to monotherapy. Overall, this platform may provide a safe and efficient strategy for cancer treatment and new insight into green, natural extracts for nanoparticle fabrication.
研究领域:
纳米技术
·
癌症治疗
·
材料科学
·
药学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 135
·期 38
·46694
·
IF 1.901
Fuxin Dong,Yue Li,Xiaohua Yuan,Ping Wang,Junjie Yang,Lei Miao
A highly transparent thermoresponsive surface that could switch its wettability at different temperatures was constructed via tea-stain-inspired chemistry. The pristine tannic acid was modified by alkyl bromide with a substitution degree of 1.7 alkyl bromide units per tannic acid molecule. A coating of the alkyl bromine modified tannic acid with a thickness of 22 ± 3 nm was deposited onto the surface of glass via auto-oxidation. A poly( N -isopropylacrylamide) (PNIPAAm) brush was grafted from the alkyl bromide initiator via surface initiation atom transfer radical polymerization with a polymer grafting density of 8.6 × 10 −3 mg/cm 2 . Due to the low thickness of the tannic acid and PNIPAAm coating, the transparency of this thermoresponsive surface remained constant at 94.3% even when the temperature was changed from 20 to 40 °C, but the water contact angle of this surface increased rapidly when the temperature was elevated from 25 to 35 °C. Due to the inevitable hydrolysis and deprotonation, this tea-stain-inspired chemistry-based coating was stable in aqueous solution with a pH of 7 or isopropanol for soaking times of up to 24 h. The coating reported here may have various potential applications such as surfaces for cell culture media, food storage, or self-cleaning materials. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46694.
研究领域:
材料科学
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化学工程
·
生物材料
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2016
·
IF 4.052
Zhuo-Xiao Han,Mohammad M. Rana,Guo-Feng Liu,Ming-Jun Gao,Da-Xiang Li,Fu-Guang Wu,Xin-Bao Li,Xiao-Chun Wan,Shu Wei
Flavour determinants in tea infusions and their changes during manufacturing processes were studied using Camellia sinensis cultivars ‘Bai-Sang Cha’ (‘BAS’) possessing significant floral scents and ‘Fuding-Dabai Cha’ (‘FUD’) with common green tea odour. Metabolite profiling based on odour activity threshold revealed that ‘BAS’ contained higher levels of the active odorants β-ionone, linalool and its two oxides, geraniol, epoxylinalool, decanal and taste determinant catechins than ‘FUD’ ( p < 0.05). Enhanced transcription of some terpenoid and catechin biosynthetic genes in ‘BAS’ suggested genetically enhanced production of those flavour compounds. Due to manufacturing processes, the levels of linalool and geraniol decreased whereas those of β-ionone, linalool oxides, indole and cis -jasmone increased. Compared with pan-fire treatment, steam treatment reduced the levels of catechins and proportion of geraniol, linalool and its derivatives, consequently, reducing catechin-related astringency and monoterpenol-related floral scent. Our study suggests that flavour determinant targeted modulation could be made through genotype and manufacturing improvements.
研究领域:
食品科学
·
植物生理学
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农学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF FOOD PROCESS ENGINEERING
·
2019
·Vol. 42
·期 4
·e13023
·
IF 1.448
Ishmael Ayim,Haile Ma,Evans Adingba Alenyorege,Yuqing Duan
The effect of brown, oolong, and green teas’ extract on the in vitro inhibition of starch digestibility of cassava, corn, plantain, and yam was explored. The starches exhibited moderately low hydrolysis rate and had moderate resistant starch ratios. Tea metabolites after extraction at different temperatures were quantified and correlated to starch inhibition at 1% introduction using principal component analysis (PCA). Total polyphenols (TP), (−)-epigallocatechin (EGC), (−)-gallocatechin gallate (GCG), (−)-catechin gallate (CG), and (−)-epigallocatechin gallate (EGCG) were positively correlated with starch digestion inhibition especially in the first and second hours of digestion. The (+)-catechin (C) and Total flavonoids (TF) in the teas, however, had a negative correlation with starch inhibition. Green tea extracts were more effective in starch digestion inhibition followed by brown tea and then oolong. TP, EGC, GCG, CG, and EGCG from green tea had the strongest inhibitory effect on starch digestion and that purified extracts of these compounds could be used at a statistically optimized combination to formulate diets with improved hypoglycemic potential. Practical applications In order to identify key components in tea responsible for hypoglycemic effect, tea extracts from three different source and their starch inhibitory properties were analyzed using starches from four plant sources. To this end, key components in the tea varieties were identified with potential hypoglycemic effect. Therefore, diets with potential hypoglycemic effect could be formulated using purified extracts from tea such as TP, (−)-epigallocatechin, (−)-gallocatechin gallate, (−)-catechin gallate, and (−)-epigallocatechin gallate under optimized conditions.
研究领域:
食品科学
·
营养学
·
植物化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF FOOD SCIENCES AND NUTRITION
·
2022
·
IF 4.444
Wen-Jing He,Nan Chen,Zhi-Long Yu,Qun Sun,Qiang He,Wei-Cai Zeng
The effect of tea polyphenols (TPs) on noodles quality was investigated, and the interaction mechanism between catechins and gliadins was explored. With TPs addition, noodles showed the significant changes in physicochemical and sensory properties. The water absorption, tensile strength and elasticity increased by 1.35%, 4.98%, 28.51% with 0.5% of TPs, and then decreased with the increasing of TPs. According to the determinations of surface hydrophobicity, spatial structure, thermal properties, amidogen and sulfhydryl content, the structure and properties of gliadin were affected by catechins. Esterified catechins tended to disrupt gliadin structures and non-esterified catechins polymerised gliadin molecules. Furthermore, molecular docking results indicated that catechins interacted with gliadin mainly by hydrogen bonds and hydrophobic action. The reactivity of catechins with gliadin was in the sequence as: epigallocatechin gallate > epicatechin gallate > epigallocatechin > epicatechin, which was based on the account of gallate and B-ring hydroxyl number discrepancy. All results suggested that catechins affected greatly on gliadin, and TPs were potentially used to improve the quality of flour products.
研究领域:
食品科学
·
化学
·
生物分子相互作用
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF FOOD BIOCHEMISTRY
·
2016
·Vol. 41
·期 1
·e12305
·
IF 0.832
Dan Li,Yingyu Chen,Yahui Huang,Lijuan Zhang,Jiagan Yang,Xingguo Xu,Qing Liu,Xu Zhang
It has been known that green tea not only possesses certain chemo-preventive effects on cancer, but also can kill directly some types of tumor cells. Niaowangzhong tea ( C. sinensis ), a special tea resource growing in Qiannan Buyi, a Miao Minority Autonomous Prefecture in Guizhou province, China, is one of the most popular medicinal beverages for local people there. The aims of this study were to analyze the quality components and their relative contents present in Niaowangzhong green tea and to investigate whether or not the water extract of this green tea has the antitumor capability in vitro and in vivo . Biochemical analysis indicated that this green tea extract contained relatively higher levels of tea polyphenols, alkaloids, flavonoids compounds and polysaccharides. In the MTT (3-(4,5-dimethyl-2-thiazolyl)−2,5-diphenyl-2- H -tetrazolium bromide) assay, this green tea extract showed inhibitory activity against several types of tumor cells, including breast, prostate, colorectal and gastric cancer cell lines, with higher selectivity toward human gastric cancer cell line MGC-803. Its 50% inhibition concentration (IC50) of MGC-803 was 32.5 μΜ as compared to that (367.9 μΜ) of normal vascular endothelial cells. Cell cycle and apoptosis analyses showed that the proportion of cells arrested at the G0/G1 phase was increased with the increase in concentration, and the proportion of apoptotic cells was also increased. Niaowangzhong green tea extract could significantly inhibit tumor-sphere formation in the in vivo antitumor experiment and the growth of MGC-803-derived tumor in nude mice. At the concentration of 500 mg/kg/day, inhibition rate was 31.0% without causing obvious toxic side effects. This study revealed a potent anti-cancer activity of this special green tea and its promising potential as chemo-preventive agent and proper dietary practice for prevention and control of cancers. Practical Application This study has indicated that Niaowangzhong green tea extract caused stronger cytotoxic effects on two kinds of digestive tract tumor cells HCT-15 and MGC-803, suggesting that as one of the most popular medicinal beverages, this green tea extract may be more suitable for treating digestive tract cancers since it can be more accessible to the locations of digestive and intestinal tracts. Therefore, this specific green tea merits further depth study on underlying mechanisms at the cellular and molecular levels and further development for potential medical application and dietary practices for prevention of cancers, especially for digestive and intestinal tracts. Co-administration of the anti-cancer drugs and Niaowangzhong green tea may reduce the toxic side effects and drug resistance while achieving desired effect because of the reason that Niaowangzhong green tea extract are mediated through the synergic effects of a variety of anti-cancer compounds present it and had no obvious toxic side effects.
研究领域:
药理学
·
肿瘤学
·
植物化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2017
·Vol. 22
·期 4
·560
·
IF 2.861
Yating Zhang,Lingbiao Gu,Fei Wang,Lingjun Kong,Guangyong Qin
As a natural and healthy beverage, tea is widely enjoyed; however, the pesticide residues in tea leaves affect the quality and food safety. To develop a highly selective and efficient method for the facile removal of pesticide residues, the subcritical butane extraction (SBE) technique was employed, and three variables involving temperature, time and extraction cycles were studied. The optimum SBE conditions were found to be as follows: extraction temperature 45 °C, extraction time 30 min, number of extraction cycles 1, and in such a condition that the extraction efficiency reached as high as 92%. Further, the catechins, theanine, caffeine and aroma components, which determine the quality of the tea, fluctuated after SBE treatment. Compared with the uncrushed leaves, pesticide residues can more easily be removed from crushed leaves, and the practical extraction efficiency was 97%. These results indicate that SBE is a useful method to efficiently remove the bifenthrin, and as appearance is not relevant in the production process, tea leaves should first be crushed and then extracted in order that residual pesticides are thoroughly removed.Keywords:subcritical butane;pesticide residue;bifenthrin;black tea
研究领域:
食品科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Chemistry-X
·
2021
·
IF 5.182
Qing-Qing Cao,Yan-Qing Fu,Jie-Qiong Wang,Liang Zhang,Fang Wang,Jun-Feng Yin,Yong-Quan Xu
Roasting, a critical process for oolong tea, has been applied to Tieguanyin tea to improve flavor attributes. To investigate the effects of the roasting on the flavor of Tieguanyin , the global metabolomics analysis on the non-volatile and volatile components were proceeded. The weakening of bitterness and astringency, caused by roasting, may be attributed to the decreasing of flavonoids glycosides and procyanidins, whereas the enhancing of sweet aftertaste to the increasing of gallic acid. Besides, l -theanine flavan-3-ols adducts ( N -ehtyl-2-pyrrolidinone substituted flavan-3-ols) increased dramatically at 130 °C compared with 105 °C, with the reduction of l -theanine and flavan-3-ols. Meanwhile, high temperature hampered the volatiles’ diversity and intensity, resulting from the lowering of floral volatiles, i.e., β-ionone, jasmine, and nerolidol, yet the nitrogen-containing heterocyclic compounds increased, e.g., pyrroles and pyrazines. The results can help to comprehensively understand the influences of roasting technology on the flavor and chemistry of oolong tea.
研究领域:
食品科学
·
化学
·
代谢组学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2020
·
IF 2.463
Chao Li,Baoguo Li,Chuanhui Zhu,Xiang Meng
New preparation condition of magnetic microcapsule was designed and optimized by response surface methodology(RSM) in this study. The optimal formula was as follows: the concentration of chitosan(CTS), magnetofluid(MHD), calcium chloride(CaCl 2 ) and sodium alginate solution(ALG) were 10.4(g/L),4.83(g/L), 5.625(g/L), and 28(g/L),respectively. The optimized magnetic microcapsules had good slow release effect, and the release time of magnetic microcapsule was up to 100 h. The chemical structure of magnetic microcapsules was determined by Fourier transform infrared(FT-IR) spectrometer. Meanwhile, the chemical composition of the magnetic microcapsule was determined by X-ray diffraction(XRD) instrument.Thermogravimetric analysis(TGA) was used to detect the thermal properties . The properties of anti-oxidation and drug release of the magnetic microcapsules were further analyzed. Most importantly, magnetic microcapsules had superparamagnetism with extremely low magnetic retention and coercivity , which could be used as a good microcapsule embolization agent for tumor endovascular embolization therapy.
研究领域:
食品科学
·
生物医学工程
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产品关联
DOI
高影响因子
npj Science of Food
·
2022
·Vol. 6
·期 1
·1-8
·
IF 7
Chong Pik Han,Chen Jianshe,Yin Danting,Qin Lanxi
Huigan is an important sensory attribute which is commonly used as a quality indicator evaluation of tea products. Previous studies showed a strong correlation between the lubrication behavior of saliva-tea compound mixture and the sensory perception of Huigan from trained panelists. This work was further designed to investigate how the effect of tea consumption on the rate of saliva secretion and its functional properties including total protein content of saliva (TPC), salivary α-amylase (AMY) and lipase activity (LP). A quartz crystal microbalance with dissipation monitoring (QCM-D) was applied to reveal the adsorption behavior of human whole saliva and how the salivary film is affected by the presence of tea compounds. Results showed a significant positive correlation among TPC, LP and Huigan intensity for subjects who are Huigan-sensitive. Compared to the desorption of salivary film, the desorption of saliva-EC/EGC (epicatechin/epigallocatechin) mixture from the gold surface by QCM-D observation showed a significant effect on Huigan intensity in sensitive group when comparing to the salivary layer (blank).
研究领域:
食品科学
·
感官评价
·
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）