JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2013
·
IF 2.906
Liping Du,Chao Wang,Jianxun Li,Dongguang Xiao,Changwen Li,Yongquan Xu
A method based on headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry was developed for the analysis of volatile methoxyphenolic compounds in pu-erh tea. Six fibers with different polarities were initially evaluated. The 75 μm carboxen/polydimethylsiloxane fiber exhibited the highest extraction efficiency and was selected for further optimization. A Plackett–Burman design was used to screen for the brewing proportion of tea and water, amount of pu-erh tea, ionic strength, extraction time, extraction temperature, desorption time, rate of agitation, and equilibrium time. A Box–Behnken design was then applied to optimize the significant factors. Under optimal conditions, the proposed method affords a wide range of linearity, high linear regression coefficients (0.996–0.999), less than 9.0% repeatability of relative standard deviation, and limits of detection ranging from 2.31 to 21.80 ng/g. The proposed method has satisfactory accuracy, with recoveries of 79.08–113.9%. This method was successfully applied for the analysis of pu-erh tea samples.
研究领域:
食品科学
·
分析化学
✓ 已验证
DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2025
·
IF 4.6
Duo Xiao,Ming Zou,Mengchun Huang
Here, we report the design of a flexible, self-powered biosensor for lactate detection based on MXene-integrated hydrogels and enzyme-modified carbon cloth electrodes. MXene was synthesized via selective etching of Ti 3 AlC 2 in HF and subsequently incorporated into a polypyrrole/polyurethane hydrogel to enhance conductivity and flexibility. The anode and cathode were fabricated by immobilizing lactate oxidase (LOD) and bilirubin oxidase (BOD) on reduced graphene oxide (rGO)-coated activated carbon cloth (ACC). Electrochemical impedance spectroscopy revealed reduced charge transfer resistance, while cyclic voltammetry confirmed strong bioelectrocatalytic activity. The sensor demonstrated a maximum power density of ∼3 μW.cm −2 at 100 mM lactate and exhibited a linear current response across physiologically relevant concentrations. Integration with the MXene-based hydrogel enabled a 15-fold increase in current output due to improved electron mobility and ionic conductivity. Mechanical testing showed stable resistivity and structure under 500 bending cycles, validating its suitability for wearable use.
研究领域:
材料科学
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纳米技术
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电化学
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生物传感器
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生物医学工程
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柔性电子学
·
能量收集
✓ 已验证
产品关联
DOI
高影响因子
Food Chemistry-X
·
2025
·
IF 8.2
Zixi Yang,Yanxia Xie,Yuanmin Zhu,Mengjie Lei,Xuemin Chen,Wenwen Jin,Chunhua Fu,Longjiang Yu
Ripened Pu-erh tea (RPT) is renowned for its distinctive flavor and health benefits. However, its complex fermentation process poses challenges in ensuring consistency in production. This study investigated RPT flavor formation through sensory evaluation, multi-omics analysis, and multivariate statistical approaches. By day 24, the tea exhibited a reddish-brown infusion and a mellow, thick taste (MT_RPT), achieving the highest sensory score (94.0, P < 0.05). Sixteen flavor-related chemical components exhibited significant changes ( P < 0.05). The contents of free amino acids, L -theanine, tea polyphenols, flavonoids, catechins, and thearubigins decreased. In contrast, the contents of total soluble sugars, caffeine, theobromine, epicatechin, and theabrownins (TBs) increased, reaching 74.1 mg/g, 65.38 mg/g, 3.13 mg/g, 3.33 mg/g, and 134.84 mg/g, respectively. Additionally, 33 nonvolatile metabolites (e.g., pelargonidin 3-O-glucoside, dihydroisorhamnetin, and puerarin) were significantly correlated with MT_RPT flavor (VIP > 1, |r| ≥ 0.8, P < 0.05) and influenced by key functional microbes, including Pantoea , Aspergillus , Brachybacterium , and Staphylococcus . By day 30, the infusion darkened, and sensory scores declined (81.4, P < 0.05), attributed to the dominance of Brevibacterium . This microbial shift reduced water-soluble pectin, free amino acids, and 11 metabolites while increasing TBs and theophylline (219.33 mg/g and 0.09 mg/g, respectively). Therefore, TBs were identified as a crucial indicator of optimal fermentation. Moreover, redundancy analysis indicated that the tea pile's central temperature, moisture content, and pH were essential fermentation parameters ( P < 0.05). These findings deepen our understanding of MT_RPT flavor development mechanisms and provide valuable insights into precise fermentation control.
研究领域:
食品科学
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微生物学
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代谢组学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Jiansheng Dong,Dunjie Fang,Meiling Xie,Yunjie Yin
Potential applications of great significance encompass bioimaging, drug delivery, fluorescence sensing, and photocatalysis, wherein CDs can excel due to their distinctive optical properties and environmental compatibility. Conversely, CDs in solutions often exhibit instability and their fluorescence is frequently quenched by aggregation phenomena and interactions with dissolved oxygen, thereby limiting their practical applications. To mitigate these challenges, an innovative encapsulation method was devised by incorporating CDs into a biodegradable poly(lactic acid)-based polyurethane matrix via a Schiff base reaction, thereby enhancing their stability and optical properties. Characterization outcomes demonstrate that the CDs@PU composite exhibits robust fluorescence retention, self-healing capabilities, and enhanced mechanical durability. Fluorescence-based active damage detection tests substantiate autonomous active damage sensing and self-repair functionalities. The study delineates how the developed material could offer a durable and multifunctional composite, which is particularly valuable for sustainable diagnostic and self-healing applications.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
Journal of Future Foods
·
2026
·
IF 10.6
Qi Fang,Chunyin Qin,Ying Peng,Zhuoqi Xu,Daxiang Li,Shanshan Hu
Chronic low-grade inflammation (CLI) is a common pathological basis for many major diseases, whose systemic regulatory mechanism remains unclear. Based on Pu-erh tea’s potential to improve gut inflammation and dysfunction in the “gut-liver/brain” axis, this study systematically explored the multi-target regulatory mechanisms of Pu-erh tea through establishing a dextran sodium sulfate-induced CLI model. The results demonstrated that CLI triggered an inflammatory cascade in the colon, liver, and brain, accompanied by liver metabolism disorders (downregulation of FXR/SREBP-1c) and gut-brain barrier damage (downregulation of ZO-1/Occludin). Pu-erh tea significantly reversed these pathological changes by reshaping the gut microbiota (increased levels of norank_f__Muribaculaceae, Lactobacillus, Akkermansia , and Dubosiella ) and promoting the biosynthesis of short-chain fatty acids (SCFAs, butyric acid and isobutyric acid), which stemmed from improved mitochondrial dysfunction. The “gut microbes-SCFAs-mitochondria” axis may hold promise as a potential strategy for phytochemicals to improve body inflammation.
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Liping Du,Chao Wang,Chenxia Zhang,Lijuan Ma,Yongquan Xu,Dongguang Xiao
Volatile compounds and sensory characteristics of instant Pu-erh teas (IPET) produced through the spray-drying process were evaluated by using headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS) and descriptive sensory analysis (DSA), and compared with Pu-erh tea (PET). A total of 208 and 204 volatiles were identified in IPET and PET, respectively. Through independent samples t -test, 98 and 55 compounds showed highly significant differences ( P ≤ 0.01) and significant differences (0.01 < P ≤ 0.05) between IPET and PET, respectively. Meanwhile, 158 compounds were defined to interpret the differences between IPET and PET using variable importance in the projection (VIP) value. Moreover，seven aroma attributes were identified through DSA. The results showed that IPET had the higher intensity of floral, fruity, sweet, and caramel-like descriptor, while PET demonstrated higher intensity of stale/musty and woody attributes.
研究领域:
食品科学
·
分析化学
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产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2022
·
IF 5.546
Feiyi Zhang,Lanlan Yu,Zhun Deng,Shuli Liu,Chenxuan Wang,Lei Liu
A variety of natural proteins have shown anti-adhesive functionality against the non-specific adsorption by proteins and bacteria. A deep understanding of the contribution of amino acid composition to the antifouling performance of a natural protein is crucial for engineering a protein-based coating layer. Herein, we synthesized five types of homo poly(amino acid)s via the ring-opening polymerization of α-amino acid N -carboxy anhydride (NCA) to include exclusively one type of amino acid from lysine (K), glutamic acid (E), tyrosine (Y), alanine (A), and phenylalanine (F). Homo poly(amino acid)s were covalently immobilized on the surfaces of quartz and polyurethane (PU), respectively. The amino acid composition effects on the wetting and anti-bacterial adhesion of a homo poly(amino acid) coating layer were evaluated. We found that the wettability of homo poly(amino acid) coating layers exhibited a dependence on the intrinsic properties of amino acid side-chain, such as the hydration free energy and dipole moment of side-chain. The activity of a homo poly(amino acid) coating layer against bacterial adsorption was found to be independent of the wetting property of the amino acid side-chain. Our findings are different from the conventional opinion that the hydration property of a material surface coating layer correlates to its anti-bacterial functionality, emphasizing the complexity of the amino acid composition contribution to the activity against the non-specific adsorption of bacteria for a protein-mimicking system.
研究领域:
材料科学
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生物材料
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生物物理学
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高分子化学
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微生物学
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DOI
高影响因子
ACS Omega
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2021
·
IF 3.512
Minhui Pang,Qiang Zuo,Bing Cao,Hongyan Li,Lina Liang,Lixia Li
Bio-based polyurethane (PU)-coated controlled release fertilizers are attracting a lot of attention; however, generally they have poor properties, so it is difficult for them to meet the agricultural needs. Herein, γ-aminopropyl triethoxy silane (KH550) was first used with nanosilica (NS) to prepare bio-based PU nanocomposite-coated urea (KSPCU). The coating microstructures and nutrient controlled release behaviors of KSPCU were investigated and compared with those of unmodified NS containing PU nanocomposite-coated urea (SPCU) and bio-based PU-coated urea (PCU). The KSPCU with KH550 exhibited an excellent controlled release performance. Its nutrient release longevity exceeded 105 d, which was nearly 6 times greater than that of PCU and 2 times more than that of SPCU, and it was much longer than that of PCU reported in previous research at a coating rate of 3 wt %. A series of characterization methods combined with water resistance capacity and porosity measurements confirmed that a hydrogen bond was formed by the reaction between the nanoparticle and PM200, the nanoparticle was bonded on the macromolecular chain, and KH550 in the coating increased the cross-linking degree, which were beneficial to slowing down the nutrient release of the KSPCU. The innovative application of KH550 on bio-based PU-coated fertilizers will provide a new coating technology for improving their controlled release property.
研究领域:
农业科学
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材料科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2021
·
IF 4.464
Rui Feng,Yao Chu,Xiaohao Wang,Qinfeng Wu,Fei Tang
Flexible biosensors have the great potential to be applied in medical diagnosis, wearable devices, fermentation and other fields. This paper proposes a manufacturing scheme of a flexible enzymatic glucose sensor coated with polyurethane modified by poly(ethylene glycol), PU-PEG, as a protective membrane, which can overcome the problems of poor consistency and short service life of the electrochemical sensor. A platinum-black electrode formed by electroplating platinum-black nanoparticles onto a flexible gold electrode is used as an enzyme carrier. The enzyme is electrosprayed evenly onto the electrode to avoid aggregation and to control quality. Glutaraldehyde is used as a cross-linking agent to immobilise the enzyme layer. Additionally, using PU-PEG as the protective membrane improves the anti-interference performance, controls the enzymatic reaction rate and makes long-term stable operation of the sensor possible. The experimental results show that the linear range of the sensor is 0.5 ~ 25 mM, the minimum detection limit is 0.25 mM, and the sensitivity is as high as 3.418 μA/mM. The measurement results of the sensors show good consistency, with a maximum absolute deviation of only 5.52%. The effective working time in 37℃ bovine serum with a glucose concentration of 5 mM is up to 23 days.
研究领域:
生物传感器
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医疗诊断
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可穿戴设备
·
发酵
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE
·
2012
·Vol. 23
·期 6
·1499-1510
·
IF 2.316
Wang Heyun,Feng Yakai,An Bo,Zhang Wencheng,Sun Minglin,Fang Zichen,Yuan Wenjie,Khan Massuri
Poly(ethylene glycol) methacrylate (PEGMA) was introduced into a polyurethane (PU) solution in order to prepare electrospun scaffold with improving the biocompatibility by electrospinning technology for potential application as small diameter vascular scaffolds. Crosslinked electrospun PU/PEGMA hybrid nanofibers were fabricated by a reactive electrospinning process with N , N ′-methylenebisacrylamide as crosslinker and benzophenone as photoinitiator. The photoinduced polymerization and crosslinking reaction took place simultaneously during the electrospinning process. The electrospinning solutions with various weight ratios of PU/PEGMA were successfully electrospun. No significant difference in the scaffold morphology was found by SEM when PEGMA content was <20 wt%. The crosslinked fibrous scaffolds of PU/PEGMA exhibited higher mechanical strength than the pure PU scaffold. The hydrophilicity of scaffolds was controlled by varying the PU/PEGMA weight ratio. The tissue compatibility of electrospun nanofibrous scaffolds were tested using human umbilical vein endothelial cells (HUVECs). Cell morphology and cell proliferation were measured by SEM, fluorescence microscopy and thiazolyl blue assay (MTT) after 1, 3, 7 days of culture. The results indicated that the cell morphology and proliferation on the crosslinked PU/PEGMA scaffolds were better than that on the pure PU scaffold. Furthermore, the appropriate hydrophilic surface with water contact angle in the range of 55–75° was favorable of improvement the HUVECs adhesion and proliferation. Cells seeded on the crosslinked PU/PEGMA (80/20) scaffolds infiltrated into the scaffolds after 7 days of growth. These results indicated the crosslinked electrospun PU/PEGMA nanofibrous scaffolds were potential substitutes for artificial vascular scaffolds.
研究领域:
生物材料学
·
组织工程学
✓ 已验证
DOI
PubMed
高影响因子
Food Bioscience
·
2024
·
IF 4.8
Liping Wang,Yukun Li,Lei Ye,Chaohui Zhi,Tao Zhang,Ming Miao
In this study, residues from black, green, and Pu-erh teas were used as raw materials to extract cellulose through alkali treatment and two-stage bleaching process. The structure and properties of the tea celluloses were compared. The yield and purity of the cellulose ranged from 6.3% to 10.1% and 75.5%–88.9%, respectively. The celluloses exhibited a typical bundle fiber morphology and an I-type crystal structure, with the Iβ structure being the predominant allomorph. Crystallinity was highest in Pu-erh tea cellulose (54.8%), followed by black tea cellulose (52.6%), and green tea cellulose (47.4%). Green tea cellulose displayed the highest initial thermal degradation temperature, while Pu-erh tea cellulose had the lowest. Pu-erh tea cellulose showed the highest moisture absorption rate (12.6%), water holding capacity (10.1 g/g), and oil holding capacity (5.7 g/g), whereas these values were lowest in black tea cellulose. The correlation coefficient between Iβ structure content and water holding capacity is −0.90, and −1.00 with oil holding capacity. This study not only opens new pathways for the recycling of tea residues and their application in food packaging but also highlights the potential of tea-derived cellulose as an innovative material for dietary fiber resources with excellent water/oil holding capacities.
研究领域:
食品科学
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材料科学
·
植物化学
✓ 已验证
产品关联
DOI
高影响因子
Food Chemistry-X
·
2024
·
IF 6.5
Tiehan Li,Yuming Wei,Mingxia Lu,Yida Wu,Yanqun Jiang,Han Ke,Aiju Shao,Jingming Ning
Piling fermentation (PF) is crucial for Pu-erh tea aroma, yet its microbial and moist-heat impact on aroma quality is poorly understood. Solid-phase microextraction, solvent-assisted flavor evaporation, and gas chromatography–mass spectrometry were used to detected and analyses the samples of sun-green green tea, sterile PF and spontaneous PF. Microbiological action promotes the formation of stale aromas. Moist-heat action promotes the formation of plum-fragrance and sweet aroma. 20 microbial markers and 28 moist-heat markers were screened from 184 volatile components. Combining odor activity values and gas chromatography-olfactometry, 22 aroma-active compounds were screened (1,2,3-trimethoxybenzene, linalool, 1,2,4-trimethoxybenzene …), and analyzed during PF processing. Aroma omission and addition experiments verified its importance. Gallic acid addition experiments successfully verified that microorganisms are the main contributors to the synthesis of methoxybenzenes. Finally, Blastobotrys, Rasamsonia , and Thermomyces showed positive correlation with the synthesis of 1-ethyl-4-methoxybenzene, 1,2,4-trimethoxybenzene, 1,2,3-trimethoxybenzene, and 1,2-dimethoxybenzene. The formation mechanism of Pu-erh tea's aroma was clarified. Exploring microbial and moist-heat effects on Pu-erh tea volatiles and understanding the methoxybenzene formation mechanism using molecular sensory science.
研究领域:
食品科学
·
微生物学
·
感官科学
·
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）