Foods
·
2022
·Vol. 11
·期 5
·628
·
IF 5.561
Meng Tao,Wenli Guo,Wenjun Zhang,Zhengquan Liu
The aroma of Keemun black tea (KBT) changes during storage. We investigated key aroma volatiles of fresh KBT (FKBT) and KBT stored for 1 year. Through gas chromatography–olfactometry–mass spectrometry/aroma extract dilution analysis (GC-O-MS/AEDA), 27 aroma volatiles with a flavor dilution (FD) value ≥16 were quantitated. In odor activity value (OAV) analysis, the two samples had nearly the same key aroma volatiles; (Z)-methyl epijasmonate was the exception. Dimethyl sulfide, 3-methylbutanal, 2-methylpropanal, and linalool had especially high OAVs. Except for β-damascenone, volatiles with OAVs > 1 had higher concentrations in FKBT, which revealed that most key aroma compounds were lost during storage. Sweet, malty, floral, and green/grassy aromas corresponded directly to certain compounds. Lastly, the addition test indicated that the addition of several key aroma volatiles decreasing during storage could enhance the freshness of KBT aroma, which may be a potential to control the aroma style of KBT or other teas in industry.Keywords:Keemun black tea;GC-O-MS;storage;aroma volatile
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Yanhua Lei,Jie Wang,Bochen Jiang,Hui Liu,Haifeng Lan,Yuliang Zhang,Guanhui Gao
In this study, we present the successful development of a unique photo-Fenton catalyst, 1T-2H MoS 2 @TP/PPy (MTP), achieved through the coating of a copolymer of tea polyphenol (TP) and polypyrrole (PPy) onto the surface of heterophase molybdenum disulfide (1T-2H MoS 2 ). This innovative approach involves the integration of hydrothermal synthesis with copolymerization techniques. Our strategy utilizes nanoflower-like 1T-2H MoS 2 as the foundational framework, which is then enveloped in TP and PPy copolymer. This innovative approach involves the integration of hydrothermal synthesis with copolymerization techniques. Our strategy utilizes nanoflower-like 1T-2H MoS 2 as the foundational framework, which is then enveloped in TP and PPy copolymer. This distinctive architecture demonstrates exceptional catalytic performance owing to the hetero-phase entanglement of 1T-2H MoS 2 , which provides a diverse array of active sites. The coupled structure of TP and iron (TP-Fe 2+ /Fe 3+ ) effectively overcome the limitation associated with the iron source. The incorporation of PPy not only reduces the recombination of photogenerated electron-hole pairs but also enhances the stability of 1T-2H MoS 2 . Remarkably, our experiments on the degradation of methylene blue (MB) and tetracycline (TC) degradation demonstrate that TP-Fe 2+ /Fe 3+ significantly expands the pH applicability range of the MTP composite catalyst. Additionally, we examine several factors, including different catalysts, H 2 O 2 addition, variations in light intensity, solution pH, temperature fluctuations, and the role of active species, to comprehensively understand their impact on the photo-Fenton degradation process. In conclusion, MTP composite exhibits robust catalytic stability and demonstrates a broad pH utilization range in the photo-Fenton oxidation process, highlighting its promising potential for a wide range of applications.
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JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jing Yang,Shiqi Wang,Nan Xu,Zhi Ye,Han Yang,Xinxing Huangfu
The nano-zero-valent iron composite (nZVI@TP-Mont) was successfully prepared using a low-cost and environmental-friendly green synthesis via tea leaves extract (tea polyphenols, TPs) and the montmorillonite (Mont). The batch and column experiments and characterization were conducted to investigate the transport behavior and Cr(VI) remediation by nZVI@TP-Mont in water/soil. Due to its particular surface characteristics and morphology (i.e., the Fe 0 core wrapped by TPs, the doped sulfur, and interlayer structure), the nZVI@TP-Mont composite showed a great removal capacity of Cr(VI) and sufficient mobility under different soil conditions. We opine the increase in the Cr(VI) reduction of nZVI@TP-Mont was attributed to the tethering of Fe 2 O 3 on the surface of Fe 0 core by the support of Mont interlayer, especially the TP-coverage around nZVI@TP-Mont surface unwrapped, thereby increasing the regenerated reactive Fe 2+ and the exposed reaction sites of Fe 0 cores to Cr(VI). The increased transportability of nZVI@TP-Mont slightly depends on the heterogeneous soil properties (i.e., ionic strength, sand/soil ratio, and pH). The two-site kinetic attachment model fitting results suggest Cr(VI)/Cr(III) speciation associated with the agglomerated nZVI@TP-Mont were efficiently immobilized in soil. Therefore, this study would benefit the efficient application of the green-synthesized nZVI@TP-Mont in in-situ remediation of soils contaminated by Cr(VI).
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BIORESOURCE TECHNOLOGY
·
2020
·
IF 7.539
Shuaizhong Zhang,Chengzhen Liu,Yongkai Yuan,Minghao Fan,Dandan Zhang,Dongfeng Wang,Ying Xu
A novel macroporous (~150 μm) double network hydrogel (TR/PAA) was prepared from tea residue and acrylic acid, and its performance was systematically evaluated. The static adsorption experiments showed that gel exhibited high selectivity and adsorption capacity, ultrafast kinetics (~10 min) for Cr(III), Pb(II) and Fe(III). The adsorption behavior showed heterogeneous and chemisorption process adsorption capacities of 206.19, 253.16, and 94.88 mg g −1 for Cr(III), Pb(II) and Fe(III), respectively. In pluralistic systems, TR/PAA showed the adsorption order of Fe(III) > Cr(III) > Pb(II). Mechanism studies confirm that nitrogen and oxygen-containing functional groups play a major role in the adsorption process. In the fixed-bed column experiments, the treatment volume of simulated wastewater reached 1400 bed volumes (BV) (21.6 L), producing only 7 BV (323 mL) eluent. This work provides a new avenue for the combination of TR/PAA reuse and heavy metal removal, which is expected to be applied in actual wastewater treatment.
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Food & Function
·
2019
·Vol. 10
·期 9
·5461-5472
·
IF 3.241
Xilian Yang,Yanli Ma,Lirong Li
β-Glucosidase (BG) was immobilized on the surface of bifunctionalized nano-magnetic iron oxide with silica and amine groups (Fe3O4@SiO2-NH2). The aroma and flavonoid aglycone enhancement effect of BG in tea soup was investigated. The immobilized BG-synthesized nanocomposite morphology and structure were characterized by using different analytical techniques, including Fourier transform infrared spectroscopy and scanning electron microscopy. The immobilized BG showed enhanced pH and temperature endurance at an optimum pH of 5.0 and temperature of 65 °C. After seven cycles of reuse, immobilized BG showed 51.8% initial activity. Immobilized-BG treatment in green tea and black tea soup elevated the aroma content by approximately 16% and 48%, respectively. In addition, flavonoid aglycones, such as myricetin, kaempferol, and quercetin, in green tea and black tea soup increased by approximately 65- and 5-fold, respectively. These results suggested that immobilized BG showed excellent potential in the enhancement of aroma and effectively hydrolyzed the flavonoid glycosides to release flavonoid aglycones in tea soup. Hence, this study provides a green and sustainable approach for the tea industry to efficiently enhance tea soup properties.
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EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY
·
2014
·Vol. 117
·期 3
·355-365
·
IF 2.033
Ping Shao,Qing Liu,Zhongxiang Fang,Peilong Sun
A comparison study has been performed for tea seed oils (TSO) extracted from different methods and sources, which were oil from cold-pressing of tea seeds [TSO(CP)], oil from supercritical fluid extraction of seeds [TSO(SCF)], and oil from supercritical fluid extraction of tea seed cake [TSCO(SCF)]. The chemical composition, thermal stability, antioxidant properties, and physicochemical properties of the oils were determined. The main ingredient in seed and cake was fat, fiber, total sugar, and considerable amounts of amino, 74.59 and 93.25 g/100 g protein, respectively were found. The results also indicated that oleic acid and linoleic acid were the dominant unsaturated fatty acids in tea seed oils, irrespective of extraction methods and sources. The TSO(SCF) contained the highest levels of squalene, lupeol, and total sterols whereas TSCO(SCF) and TSO(CP) had higher contents of total phenolics and α-tocopherol. The TG/DTG curves showed TSO(CP) and TSO(SCF) were more thermally stable than TSCO(SCF), and the antioxidant activity assays demonstrated that TSO(CP) and TSCO(SCF) exhibited stronger radical scavenging ability. The overall physicochemical properties of the tested oils indicated that TSO(SCF) had the best oil quality. This work may be useful to food oil industry to produce high quality tea seed oils through utilization of suitable oil extraction methods and raw materials. Practical applications: The growing consumption of green tea promoted the increased production of tea seed, which has totaled as much as 1.6 million tons annually since 2011. As an important source of edible oil, the exploitation rate of tea seed is insufficient (≤1%) in China. This study indicates that oil extracted from tea seed as well as cold-pressing cake can be exploited for high quality edible oil because of similar fatty acid composition and better bioactive compound composition (e.g., α-tocopherol, total phytoterols, and lupeol) compared to olive oil. Further, the evaluation of thermal stability provides basis for oil's refining to prepare salad oil, mayonnaise, etc. TSO(SCF) and TSCO(SCF) both had good antioxidant activity, which is applicable in the industry of skincare. A comparison study has been performed for tea seed oils (TSO) extracted from different methods and sources, which were oil from cold-pressing of tea seeds [TSO(CP)], oil from supercritical fluid extraction of seeds [TSO(SCF)], and oil from supercritical fluid extraction of tea seed cake [TSCO(SCF)]. The chemical composition, thermal stability, antioxidant properties, and physicochemical properties of the oils were determined.
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Foods
·
2024
·Vol. 13
·期 13
·2106
·
IF 4.7
Yuge Guan,Sainan Lu,Yan Sun,Rentao Zhang,Xinghua Lu,Linjiang Pang,Lei Wang
The Lanzhou lily is a regionally distinctive vegetable; the emergence of lightly processed lilies has addressed the inconvenience of consuming fresh lilies. However, the cleaning and impurity removal during the processing of lightly processed lily may strip off its original protective barrier and affect the edible quality. As one of the preservation methods, tea tree essential oil (TTEO) has the characteristics of being green, safe, and efficient preservative properties. This study focused on investigating the effects of different concentrations (25 μL/L, 50 μL/L, and 100 μL/L) of TTEO on the quality and microbiological safety of lightly processed lily. The results showed that compared with the control, appropriate concentrations of TTEO treatment could delay weight loss, improve appearance, firmness, and sensory quality, and maintain microbiological safety with the best effect observed at 50 μL/L. Meanwhile, TTEO treatment induced phenylalanine ammonia-lyase activity, thereby increasing the total phenolic content. Furthermore, TTEO enhanced the superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity, which reduced O2-· production rate and H2O2content. TTEO inhibited lipoxygenase (LOX) activity, reducing the relative conductivity and malondialdehyde content, thereby delaying lipid peroxidation and quality deterioration. This indicates that TTEO could enhance antioxidant capacity by regulating reactive oxygen species (ROS) metabolism and delay the quality deterioration of lightly processed lily by inhibiting lipid peroxidation.
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JOURNAL OF FOOD SCIENCE
·
2024
·Vol. 89
·期 12
·9198-9213
·
IF 3.2
Lijuan Du,Yanping Ye,Jinliang Shao,Yutong Wang,Guolei Zhu,Hua Jiang,Hongcheng Liu,Zhenhuan Liu
The assessment of aroma plays a crucial role in determining the characteristics and quality of Pu-erh tea. The volatile compounds present in Pu-erh raw tea sourced from five regions in Yunnan Province have been studied using gas chromatography-mass spectrometry (GC-MS) in conjunction with headspace solid phase microextraction (HS-SPME). A total of 69 aroma-active compounds were identified, with alcohols, ketones, and aldehydes being the predominant component types. Furthermore, notable variations were observed among four pairs of volatile terpenoid enantiomers. Significant discrimination was achieved using orthogonal partial least squares discrimination analysis ( R ( x 2 ) = 0.926, R ( y 2 ) = 0.843, Q 2 = 0.501). Moreover, 33 important differential compounds were identified based on variable importance in the projection values (VIP > 1.0) and one-way ANOVA analysis ( p < 0.05). Subsequently, a KEGG pathway analysis was conducted, revealing enrichment pathways primarily focused on the mevalonate pathway, steroid biosynthesis, and fatty acid biosynthesis. Ultimately, the key volatile compounds and major aroma-contributing compounds were successfully identified.
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FOOD CHEMISTRY
·
2025
·
IF 9.8
Long-Jie Xu,Qing-Qing Cao,Si-Han Deng,Wen-Jiang Dong,Qian Zou,Yong-Quan Xu,Xing-Hui Li
In this study, the effect of calcium ions (Ca 2+ ) on the astringency sensation in green tea infusion was explored using sensory evaluation, in vitro oral soft tribology, and targeted metabolomics. Ca 2+ enhanced the astringency intensity (from 2 to 6) and the turbidity (from 10.0 to 83.3), and decreased the particle size (from 1468.0 to 817.65) in cold-brewing tea. Catechins influenced the astringent sensation in the presence of Ca 2+ and the content of (−)-Epicatechin, (−)-Epigallocatechin, and (−)-Epigallocatechin gallate (EGCG) solution in green tea infusion after oral processing all reduced. The friction coefficient of hot-brewed tea (μ, 1.6–2.8) was greater than that of cold-brewed tea (μ, 1.0–2.6), and EGCG increased with the enlarged Ca 2+ concentrations. Ca 2+ increased the astringency mainly through catechins and saliva lubrication. The in vitro soft oral tribology could be usefully explored the enlarged astringency sensation by Ca 2+ , and applied to the astringency regulation of beverages.
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INDUSTRIAL CROPS AND PRODUCTS
·
2025
·
IF 6.2
Kuang Luo,Ao Chen,Yiting Liu,Jie Yang,Ning Cai,Jumei Li
Surface-enhanced Raman spectroscopy (SERS) has been perceived as a valuable tool in ensuring food safety due to its rapid and intuitive nature. In this study, we demonstrate a novel cellulose-ZIF-8-noble metal nanostructure as a SERS substrate for the analysis of pesticide residues in food. Cellulose nanocrystal (CNC) acting as a scaffold, we systematically integrate ZIF-8 and Ag nanoparticles to fabricate tailored necklace-like CNC/ZIF-8/Ag core/shell nanostructures. SERS analysis reveals the CNC/ZIF-8/Ag presents an high enhancement factor of 6.39 × 10 4 , a low limit of detection (LOD) of 10 −9 mol/L, and a relative standard deviation of 10.24 % across 20 substrate batches for 4-mercaptobenzoic acid, underscoring its robust sensitivity and reproducibility. Moreover, its utility extends to the quantification of diquat dibromide (DQ) in standard solutions and green tea leaves, showcasing LODs of 6.61 × 10 −9 mol/L and 6.76 × 10 −8 mol/L, respectively, thereby exhibiting promising capabilities for ultra-sensitive pesticide detection in food. The exceptional SERS property can be ascribed to the enriching properties of the porous ZIF-8 nanostructures. Significantly, when exposed to UV light, the CNC/ZIF-8/Ag nanostructures efficiently degrade DQ within 60 min. Furthermore, their practical reusability under UV light is proved by high SERS performance across five detection cycles. These results emphasize the immense potential of CNC/ZIF-8/Ag in SERS-based trace pesticide detection.
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Agriculture-Basel
·
2024
·Vol. 14
·期 12
·2289
·
IF 3.3
Youru Yao,Juying Li,Kang Ma,Jingyi Zhang,Yuesheng Lin,Huarong Tan,Jia Yu,Fengman Fang
Dissolved organic matter (DOM) is widely present in soil environments and plays a crucial role in controlling the morphology, environmental behavior, and hazards of arsenic (As) in soil. In the Fe-rich red soil of tea plantations, the decomposition of tea tree litter complicates DOM properties, leading to more uncertain interactions between DOM, Fe, and As. This study focused on three tea plantations in Huangshan City to investigate the contents of DOM, Fe, and As in surface red soils (Ferralsols) and establish their correlations. Three-dimensional fluorescence spectroscopy and PARAFAC analysis methods were used to analyze the DOM components and fluorescence signatures. Additionally, the process and mechanism of the binding of DOM-Fe with As were explored through laboratory experiments on the morphological transformation of As by DOM-Fe. The results showed that the pH values of the soils in the three tea plantations ranged from 3.9 to 5.2, and the entire sample was strongly acidic. The DOM exhibited strong intrinsic properties and low humification, containing three types of humic acid components and one intermediate protein component. The DOC content in the Fe-rich red soil did not have a direct correlation with Fe and As, but the interaction of DOM fractions with Fe significantly influenced the As content. Specifically, the interaction of protein-like fractions with Fe had a more pronounced effect on the As content. The maximum sorption rate of As by DOM was 15.45%, and this rate increased by 49 to 75% with the participation of Fe. In the configuration of the metal electron bridge, Fe acts as a cation, forming a connecting channel between the negatively charged DOM and As, thus enhancing the DOM’s binding capacity to As. DOM-Fe compounds bind As through surface pores and functional groups. These findings provide deeper insights into the influence of DOM on As behavior in Fe-rich soil environments and offer theoretical support for controlling As pollution in red soil.
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Journal of Cleaner Production
·
2024
·
IF 9.7
Liushan Jiang,Yue Zhang,Shiyu Huang,Jingwen Niu,Huanhuan Liu,Shuai Yuan,Qingxiang Zhou
Polycyclic aromatic hydrocarbons (PAHs) and sulfur-containing heterocyclic aromatic hydrocarbons (PASHs) are typical organic pollutants that are commonly present in the environment. Due to the continuous accumulation and transfer in the food chain, they will pose a significant threat to human life and health. In the present work, a new method was constructed with a ternary magnetic nanocomposite (Fe 0 @MXene@COF-LZU1) based magnetic solid phase extraction in combination with gas chromatography-tandem mass spectrometry (GC-MS/MS) for sensitive determination of them at trace level in Chinese tea samples. The magnetic nanomaterial Fe 0 @MXene@COF-LZU1 was synthesized via reduction and Schiff base reactions. The experimental results demonstrated that Fe 0 @MXene@COF-LZU1 had high adsorption ability and satisfactory chemical stability. Under the optimal experimental conditions, the method possessed good linearity in the concentration ranges of 0.0005 μgL −1 - 50 μg L −1 for dibenzothiophene (DBT), phenanthrene (PHE), fluoranthene (FLT) and pyrene (PYR), and 0.001 μg L −1 - 50 μg L −1 for 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The detection limits of this method were in the range of 0.014 ng L −1 -0.83 ng L −1 . The results of real samples demonstrated that the designed magnetic nanocomposite had a promising application prospect for measuring PAHs and PASHs.
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