FOOD CHEMISTRY
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2021
·
IF 7.514
Yu-Meng Zhu,Jun-Jie Dong,Jing Jin,Jin-Hua Liu,Xin-Qiang Zheng,Jian-Liang Lu,Yue-Rong Liang,Jian-Hui Ye
Roasting process impacts the chemical profile and aroma of roasted tea. To compare the impacts of far-infrared irradiation and drum roasting treatments (light, medium and heavy degrees), the corresponding roasted teas were prepared from steamed green tea for chemical analyses and quantitative descriptive analysis on aroma, and correlations between volatiles and aroma attributes were studied. There were 8 catechins, 13 flavonol glycosides and 105 volatiles quantified. Under heavy roasting treatments, most catechins and flavonol glycosides decreased, and aldehydes, ketones, furans, pyrroles/pyrazines, and miscellaneous greatly increased, while far-infrared irradiated teas had distinct nutty aroma compared with the roasty and burnt odor of drum roasted teas. The weighted correlation network analysis result showed that 56 volatiles were closely correlated with the aroma attributes of roasted teas. This study reveals the differential chemical and sensory changes of roasted teas caused by different roasting processes, and provides a novel way for flavor chemistry study.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2021
·
IF 4.098
Xiaoyu Zhu,Wenjin Li,Ruimei Wu,Peng Liu,Xiao Hu,Lulu Xu,Zhengwu Xiong,Yangping Wen,Shirong Ai
Surface enhanced Raman spectroscopy based on rapid pretreatment combined with Chemometrics was used to determine chlorpyrifos residue in tea. Au nanoparticles were used to as enhance substrate. Different dosages of PSA and NBC were investigated to eliminate the tea substrate influence. Competitive adaptive reweighted sampling (CARS) was used to optimize the characteristic peaks, and compared to full spectra variables and the experiment selected variables. The results showed that PSA of 80 mg and NBC of 20 mg was an excellent approach for rapid detecting. CARS - PLS had better accuracy and stability using only 1.7% of full spectra variables. SVM model achieved better performance with R 2 p = 0.981, RMSEP = 1.42 and RPD = 6.78. Recoveries for five unknown concentration samples were 98.47 ~ 105.18% with RSD − 1.53% ~ 5.18%. T-test results showed that t value was 0.720, less than t 0.05,4 = 2.776, demonstrating that no clear difference between the real value and predicted value. The detection time of a single sample is completed within 15 min. This study demonstrated that SERS coupled with Chemometrics and QuEChERS may be employed to rapidly examine the chlorpyrifos residue in tea towards its quality and safety monitoring.
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ULTRASONICS SONOCHEMISTRY
·
2020
·
IF 6.513
Haisong Wang,Jinran Chen,Pengfei Ren,Yiwen Zhang,Stanley Omondi Onyango
In this study, the impact of ultrasound irradiation on the structural characteristics and antioxidant properties of yellow tea polysaccharides with different molecular weights (Mw) were investigated. Native yellow tea polysaccharide containing YTPS-3N, YTPS-5N and YTPS-7N were prepared through precipitation with ethanol at various concentrations of 30%, 50%, and 70%, respectively, and irradiated with high intensity ultrasound (20 kHz) for 55 min to yield yellow tea polysaccharide including YTPS-3U, YTPS-5U and YTPS-7U. The molecular weight (Mw) of YTPS-3N (from 37.7 to 15.1 kDa) and YTPS-5N (from 14.6 to 5.2 kDa) sharply decreased upon ultrasound irradiation, coincidentally particle size (Zavg) was also significantly reduced for YTPS-3N (40%), YTPS-5N (48%) and YTPS-7N (54%). The high-performance liquid chromatography and Fourier transform-infrared spectroscopy analysis revealed a partial degradation of native yellow tea polysaccharide treated with ultrasound, though the monosaccharide composition was not altered. Furthermore, changes in morphology and the breakdown of native yellow tea polysaccharide upon irradiation was confirmed with the circular dichroism spectrum, atomic force and scanning electron microscopy. As a consequence, irradiation of yellow tea polysaccharide increased free radical scavenging activity with YTPS-7U exhibiting the highest levels of 2, 2-diphenyl-1-picrylhydrazyl free radical, superoxide and hydroxyl radicals scavenging activity. These results suggest that the alteration of the spatial structure of yellow tea polysaccharide can enhance its antioxidant activity which is an important property for functional foods or medicines.
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FOOD CHEMISTRY
·
2020
·
IF 6.306
Jie He,Hongxia Li,Lulu Zhang,Xiao Zhi,Xin Li,Xin Wang,Zijian Feng,Guangxia Shen,Xianting Ding
Due to the excessive use of fungicides, pesticide residues have become a growing concern in recent years. Herein, we demonstrated an easy-prepared and low-cost surface enhanced Raman Scattering (SERS) chip composed of 3D silver microspheres (AgMSs) pattern for the quantitative testing of carbendazim in Chinese tea. Compared with the common monolayer SERS substrate, the 3D patterns formed by self-assembly AgMSs with fine nanostructure can offer much more aggregation-induced hotspots and generate strong 3D synergetic effects. Furthermore, when the thickness of the 3D pattern exceeded 6 μm, we replaced the conductive supporting coatings using the glass slides to reduce the cost without any impact on SERS properties. The prepared 3D chips achieved the determination of carbendazim within the linear range of 0.1–10 mg/L and the detection limit of 0.01 mg/L. It is simple and sensitive enough for the detection of most pesticide residues or other harmful organic molecules in our food or environment.
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JOURNAL OF FOOD SCIENCE
·
2020
·Vol. 85
·期 5
·1450-1461
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IF 2.479
Xiaoqin Wang,Wencong Jia,Guoyin Lai,Lijuan Wang,María del Mar Contreras,Daomao Yang
Bound phenolic compounds have rarely been reported in vegetable oils and this may be due to little research about the extraction. Deep eutectic solvents (DESs), recently applied in the extraction of phenolic compounds as alternatives to organic solvents, were adopted in the extraction of free and bound phenolic compounds from tea seed oil in this work. First, the phenolic compounds were analyzed by ultra-high-performance liquid chromatography with quadrupole-time-of-flight and triple-quadrupole tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) for characterization and UHPLC-QqQ-MS/MS for quantification and 25 phenolic compounds were found to exist in both free and bound forms. Then, DESs were screened for extraction of free and bound phenolic compounds from tea seed oil as the pretreatment for analysis and the results showed that hydrogen bond donors (HBDs) and temperature significantly affected the extraction efficiency of DESs. Finally, free phenolic compounds (83.91 µg/g) and bound phenolic compounds (25.71 µg/g), extracted by the DES with glycerol as HBD at 50 °C, were 51.0% and 93.2% higher than those extracted by methanol/water (60%, v/v), respectively. This work not only advanced the basic data of phenolic compounds in tea seed oil but also explored an efficient extraction method for scientific analysis of free and bound phenolic compounds.
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WATER RESEARCH
·
2020
·
IF 9.13
Di Zhang,Feifei Wang,Youli Duan,Shenghua Chen,Aihong Zhang,Wenhai Chu
Disinfection by-products (DBPs) are associated with various adverse health effects. Diversiform advanced treatment processes have been applied for the control of DBPs, but DBPs can still be frequently detected in tap water . Tea-leaves can be made into popular beverage and is itself a porous bio-adsorbent. By simulating tea brewing process, this study evaluated the removal of DBPs from drinking water during the tea brewing process. Removal of four trihalomethanes (THMs) and four haloacetamides (HAMs) by different fermentation degree tea-leaves was investigated. Little DBPs were removed by unfermented and semi-fermented tea-leaves (i.e., Meitan turquoise bud and Dahongpao tea) with less than 5% removal of HAMs, whereas 40% HAMs can be removed by fermented tea (i.e., Jinjunmei tea and Shuixian tea). Tea soup is neutral and slightly acidic, so little DBP hydrolysis was observed under typical tea-leaf brewing process. DBPs were mainly removed by volatilization and adsorption during tea brewing. Removal difference caused by DBP volatilization is very small. The DBP removal difference of four kinds of tea-leaves may be caused by fermentation degree. The surface of unfermented Meitan turquoise bud had a smooth and regular morphology, whereas a rough, irregular, hollow and spongy surface of fermented tea (i.e., Jinjunmei and Shuixian tea) was observed. Generally, the higher the degree of tea fermentation, the more adsorption sites, and the more removal of DBPs. Finally, the model, which takes the DBP initial concentration, tea-leaf dose and brewing time into account, was established under the experimental conditions to predict the variation of DBP concentration during tea brewing, and suggestions for DBP removal were provided to reduce DBP exposure risk. The integrated toxic risk during tea brewing was also investigated, and about 30% integrated cytotoxicity and 26% genotoxicity was reduced during Jinjunmei and Shuixian tea-leaf brewing.
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CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2020
·
IF 3.35
Zexian Zhu,Dongqing Liu,Sizhou Cai,Yankun Tan,Jing Liao,Yuanjian Fang
Two multi-amine, metformin (MTM) and polyethyleneimine (PEI), were used to prepare separative layer of composite membrane through chemical deposition with tea polyphenols (Tph), an inexpensive mixture of nature polyphenols, on a hybrid polysulfone (Psf) membrane. The supporting layer was a blend membrane of Psf, coupling agent treated sepiolite and cetyltrimethylammonium bromide (CTAB). Sepiolite and the surfactant improved surface hydrophilicity of membrane. Pure water flux (PWF) of membranes was increased from 33.97 to 611.46 L m −2 h −1 bar −1 . The optimum mass ratio for MTM to Tph and PEI to Tph were 9.4:1 and 2.4:1 in chemical deposition reaction, respectively. MTM-Tph (MT) surface was negative charged while PEI-Tph (PT) was positive charged. Monomer reactivity determined the thickness of functional layer. Both composite membranes showed dyes rejection capacity at 1 bar. PT layer was thicker than MT, so did its rejection for dyes. The rejection of PT for 5 dyes were all higher than 98% and remained at 99.3% and 98.6% in 200 h for Congo red (CR) and neutral red (NR). PT membrane displayed the potential in textile waste water treatment.
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ACS Omega
·
2020
·
IF 2.87
Xinliang Li,Guancheng Jiang,Xiulun Shen,Gongrang Li
Drilling fluids with poor filtration property are disadvantageous for well drilling, easily causing wellbore instability and formation collapse. This work reports the novel utilization of tea polyphenols (TPs) as a fluid loss additive in the bentonite–water-based drilling fluids (BT-WDFs). The influence of TP concentration and temperature on the filtration property of the fluids was described. The results showed that an increase in the TP concentration contributed to a decrease in fluid loss. Especially BT-WDFs added with 3.0 wt % TP exhibited a low fluid loss (less than or approximately 10 mL) at room temperature and high temperatures (∼150 °C), displaying better filtration property and temperature resistance than common fluid loss agents. Through the investigations on the viscosity, the particle size of TP/BT-WDFs, and micromorphology of filter cakes, the dispersion effect of TP was considered as the dominant factor for the filtration property of TP/BT-WDFs. TP molecules, containing many functional groups, could attach to the surface of bentonite platelets, improve the hydration of bentonite particles, and promote the dispersion of bentonite particles. At room temperature, TP facilitated the dispersion of hydrated bentonite. The existing “house-of-cards” structure was weakened, decreasing the particle size and viscosity of TP/BT-WDFs. At high temperature, bentonite dehydrated and aggregated, thereby increasing the particle size of bentonite particles, decreasing the viscosity of bentonite dispersion, and resulting in a high fluid loss. The addition of TP dispersed bentonite from face-to-face (FF) attraction to edge-to-face (EF) attraction, recovered the house-of-cards structure, and increased the viscosity of TP/BT-WDFs. Under the dispersion effect of TP, an appropriate grain composition of bentonite particles was formed and the pore throats were plugged to prevent the penetration of water. Finally, a compact and thin filter cake was built and the fluid loss was greatly reduced. The TP/BT-WDFs exhibited good filtration property. TP is a prospective candidate to be a high-performance and biodegradable fluid loss additive in well-drilling applications.
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MOLECULAR PLANT-MICROBE INTERACTIONS
·
2021
·
IF 4.171
Xingtao Bao,Rui Yang,Shilong Jiang,Jinping Zhao,Delu Wang,Dongxue Li,Xian Wu,Baoan Song,Zhuo Chen
Diseases caused by fungi can affect the quality and yield of the leaves of tea [ Camellia sinensis (L.) Kuntze]. At present, the availability of highly effective and safe fungicides for controlling tea plants remains limited. The objectives of this study were to identify novel compounds with antifungal activities and to determine their molecular mechanisms. A series of sulfone compounds containing 1,3,4-oxadiazole were evaluated in China for their antifungal activities against several pathogens causing foliar diseases and high production losses. Transcriptomics and bioinformatics were used to analyze the differentially expressed genes of Lasiodiplodia theobromae treated with a representative compound, jiahuangxianjunzuo (JHXJZ). Moreover, the effects of JHXJZ on ergosterol content, membrane permeability, cell structure, and seven key genes involved in the ergosterol biosynthetic pathway were investigated. JHXJZ had a strong antifungal activity against L. theobromae in vitro, with an effective concentration giving 50% inhibition of 3.54 ± 0.55 μg/ml, and its curative efficacies on detached tea leaves reached 41.78% at 100 μg/ml. JHXJZ upregulated 899 genes ( P < 0.05) and downregulated 1,185 genes ( P < 0.05) in L. theobromae . These genes were found to be associated with carbohydrate metabolic processes, which are closely related to steroid biosynthesis in the Kyoto Encyclopedia of Genes and Genomes pathways. Because JHXJZ regulates the key genes of sterol biosynthesis, it decreased the ergosterol content, increased cell-membrane permeability, changed the cellular structure, enhanced the roughness of the surface of the hyphae, and resulted in degradation of the hyphal nuclei and necrosis of the hyphal cytoplasm. Our study demonstrates that JHXJZ is a fungicide with a novel mechanism of action that differs from that of triazole fungicides. JHXJZ has potential for applications in controlling tea plant diseases.
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JOURNAL OF APPLIED MICROBIOLOGY
·
2015
·Vol. 119
·期 5
·1253-1262
·
IF 2.479
Yu D.,Wang J.,Shao X.,Xu F.,Wang H.
AimsThe essential oil of Melaleuca alternifolia (tea tree) has been evaluated as a potential eco‐friendly antifungal agent against Botrytis cinerea. In this study, we investigated the antifungal activity and mode of action of tea tree oil (TTO) and its components against B. cinerea.Methods and ResultsOf the components we tested in contact phase, terpinen‐4‐ol had the highest antifungal activity, followed by TTO, α‐terpineol, terpinolene, then 1,8‐cineole. As one of characteristic components of TTO, terpinen‐4‐ol treatment led to pronounced alterations in mycelial morphology, cellular ultrastructure, membrane permeability under scanning electron microscope, transmission electron microscope and fluorescent microscope, and also reduced the ergosterol content of fungi. As another characteristic component, 1,8‐cineole caused serious intracellular damage but only slightly affected B. cinerea otherwise. When terpinen‐4‐ol and 1,8‐cineole were used together, the synergistic antifungal activity was significantly higher than either component by itself.ConclusionsThe results of our study confirmed that terpinen‐4‐ol and 1,8‐cineole act mainly on the cell membranes and organelles of B. cinerea, respectively, and when combined are similar to TTO in antifungal activity due to their differences.Significance and Impact of the StudyUnderstanding the mechanism of terpinen‐4‐ol and 1,8‐cineole antifungal action to B. cinerea is helpful for investigation on their synergistic effect and explaining antifungal action modes of TTO.
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Frontiers in Plant Science
·
2016
·
IF 4.495
Xu Huanhuan,Wang Ya,Chen Yana,Zhang Pan,Zhao Yi,Huang Yewei,Wang Xuanjun,Sheng Jun
Galloylated catechins, as the main secondary metabolites in the tea plant, including (-)-epigallocatechin-3-gallate and (-)-epicatechin-3-gallate, comprise approximately three-quarters of all the tea plant catechins and have stronger effects than non-galloylated catechins, both on the product quality in tea processing and the pharmacological efficacy to human beings. The subcellular localization of galloylated catechins has been the primary focus of studies that assess biosynthesis and physiological functions. Classical histochemical localization staining reagents can not specifically detect galloylated catechins; thus, their subcellular localization remains controversial. In the present study, we generated a monoclonal antibody (mAb) against galloylated catechins, which can be used for the subcellular localization of galloylated catechins in the tea plant by immunohistochemistry. Direct ELISA and ForteBio Octet Red 96 System assay indicated the mAb could recognize the galloylated catechins with high specificities and affinities. In addition, tea bud was ascertained as the optimal tissue for freezing microtomic sections for immunohistochemistry. What’s more, the high quality mAbs which exhibited excellent binding capability to galloylated catechins were utilized for the visualization of them via immunohistochemistry. Our findings demonstrated that vacuoles were the primary sites of localization of galloylated catechins at the subcellular level.
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FOOD RESEARCH INTERNATIONAL
·
2017
·
IF 3.086
Xiaoqin Wang,Qiumei Zeng,María del Mar Contreras,Lijuan Wang
In Asia, tea seed oils (seed oils from Camellia oleifera , C. chekiangoleosa , and C. sinensis ) are used in edible, medicinal, and cosmetic applications. However, these oils differ in their fatty acid contents, and there is little known about their phenolic compounds . Here we analyzed the phenolic compounds of seed oils from three species gathered from 15 regions of China. Twenty-four phenolic compounds were characterized by HPLC-Q-TOF-MS, including benzoic acids (6), cinnamic acids (6), a hydroxyphenylacetic acid, flavanols (4), flavonols (3), flavones (2), and dihydroflavonoids (2). Some of these phenolic compounds had not previously been reported from C. sinensis (20), C. oleifera (15), and C. chekiangoleosa (24) seed oils. Quantification was done by HPLC-QqQ-MS using 24 chemical standards. The total concentrations in the studied samples ranged from 20.56 to 88.56 μg/g. Phenolic acids were the most abundant class, accounting for 76.2–90.4%, with benzoic acid, found at up to 18.87 μg/g. The concentration of catechins, typical of tea polyphenols, ranged between 2.1% and 9.7%, while the other flavonoids varied from 4.2% to 17.8%. Although the cultivation region affected the phenolic composition of the Camellia seed oils, in our hierarchical clustering analysis, the samples clustered according to species. The phenolic composition of the seed oils from C. oleifera and C. chekiangoelosa were similar. We found that the phenolic categories in Camellia seed oils were similar to tea polyphenols, thereby identifying a source of liposoluble tea polyphenols and potentially accounting for some of the reported activities of these oils. In addition, this work provides basic data that allows distinction of various Camellia seed oils, as well as improvements to be made in their quality standards.
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