Food Quality and Safety
·
2022
·
IF 3.949
Kang Yuting,Li Chenghua,Li Huiru,Li Jing,Jiang Kezhi
Polycarboxylic acids (PACs) are important metabolic products in almost all living bodies, yet current analytical methods for detection of PACs in tea beverages are still unsatisfactory due to the complex matrix and physicochemical properties of PACs. In this work, a rapid method was developed for the simultaneous determination of 7 PACs, including tartaric acid, α-ketoglutaric acid, malic acid, malonic acid, cis-aconitic acid, succinic acid, and fumaric acid, in beverages, based on selective removal of the matrix in combination with liquid chromatography–mass spectrometry (LC-MS) analysis. By stirring with activated carbon and the Na2CO3 solution, the matrix in beverages was selectively removed, and PACs were almost retained in the supernatant of diluted Na2CO3 solution. Under optimized parameters, the limit of quantitation for the PACs was in the range of 1–50 ng/mL, and the content of the PACs in 8 beverages was determined with the recovery range of 72.2%–122.5%. The contents of malic acid, malonic acid, and succinic acid in tea beverages were found to be greater than those in non-tea beverages. Moreover, the concentration of these PACs in beverages was found to be multiplied many times in their deterioration period, especially for fumaric acid and α-ketoglutaric acid. These results indicated that PACs can be selected as a criterion to differentiate qualified tea beverages from spoiled beverages.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Qi Jiang,Ping Li,Bin Wang,Jiu-Hua She,Yun Liu,Ping Zhu
Inorganic-organic hybrid coatings prepared via an impregnation assembly of eco-friendly materials exhibited dramatically flame-retardant properties on flexible polyurethane foam (FPUF). A nickel-complex of tea polyphenols (TP-Ni) was synthesized, and TP-Ni and laponite (LAP) were coated on the surface of FPUF. LAP/TP-Ni can be homogeneously dispersed on the surface of FPUF. Moreover, the melt-dripping phenomenon of 1LAP/4TP-Ni/FPUF was completely inhibited during the vertical flame test (UL-94) with 41.2 wt% weight gain, and it showed self-extinguished behaviors at once and passed the UL-94 V-0 rating. Additionally, the values of peak heat release rate and peak smoke production rate of 1LAP/4TP-Ni/FPUF were reduced by 71.6% and 60.9%, compared with the control. The content of gaseous toxic substances, such as CO and NCO-containing compounds, was also decreased, indicating the effect of TP-Ni/LAP on the toxicity suppression of flame-retardant FPUF. Encouragingly, the coatings deteriorated the tensile property of FPUF inconspicuously. Interestingly, the coatings do not contain traditional flame retardant elements, which offers an innovative approach for designing flame retardants. Thus, these inorganic-organic hybrid coatings show the promising potential to decrease the fire risk of FPUF.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Jing Lei,Wei Li,Meng-Xi Fu,An-Qi Wang,Ding-Tao Wu,Huan Guo,Yi-Chen Hu,Ren-You Gan,Liang Zou,Ying Liu
Although sweet tea is rich in bioactive polysaccharides , the knowledge regarding their structures, bioactivities, and gut microbial metabolism is still limited. Therefore, in order to promote the application of sweet tea polysaccharide (STP) in the food industry, the pressurized hot water extraction (PHWE) of STP was optimized, and its structural properties and biological effects as well as microbial fermentation characteristics were investigated. The maximum extraction yield (4.64 % ± 0.03 %) of STP extracted by PHWE was obtained under the optimal conditions. Both homogalacturonan and arabinogalactan might exist as major polysaccharide fragments in STP. Additionally, STP exerted obviously in vitro antioxidant, anti-diabetic, and immunostimulatory effects, which might be related to its chemical properties, such as uronic acids , conjugated polyphenolics, and esterification degree. Furthermore, STP could be consumed by intestinal microbiota , and its fermentability was about 54 % at the end stage of fecal fermentation. Indeed, STP could modulate the microbial composition via improving the growth of several beneficial microbes, causing the release of beneficial short-chain fatty acids. Collectively, the findings indicate that the PHWE is an efficient method for extracting bioactive polysaccharides from sweet tea, and results can also provide a scientific basis for developing STP into functional foods or functional ingredients.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2022
·Vol. 11
·期 12
·1740
·
IF 5.561
Cong Liu,Chao Wang,Tingting Zheng,Miaomiao Zhao,Wanying Gong,Qiaomei Wang,Liang Yan,Wenjie Zhang
The aroma profile of sun-dried black tea (SBT) was identified by headspace solid–phase microextraction (HS–SPME) coupled with gas chromatography–mass spectrometry (GC–MS) and gas chromatography–olfactometry (GC–O). A total of 37 scents were captured by using the GC–O technique, and 35 scents with odor intensities ranging from 1.09 ± 1.93 to 9.91 ± 0.29 were identified. Twenty-one compounds were further identified as key odor-active compounds with odor activity values (OAVs) greater than or equal to one. These key odor-active compounds were restructured with their detected concentrations, and the aroma profile of the selected SBT sample was successfully imitated to a certain extent. An omission test was performed by designing 25 models and confirmed that (E)-β-damascenone,β-ionone, dihydro-β-ionone, linalool, and geraniol were the key odor-active compounds for the aroma profile of SBT. Meanwhile, phenylethyl alcohol, (E)-2-decenal, hexanal, and methyl salicylate were also important to the aroma profile of SBT. This study can provide theoretical support for the improvement of the aroma quality of sun-dried black tea.Keywords:sun-dried black tea;odor-active compound;gas chromatography–olfactometry;odor activity value;aroma recombination;omission test
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2022
·
IF 6.056
Xia Yin,Jian'an Huang,Jing Huang,Wenliang Wu,Tong Tong,Shujuan Liu,Lingyun Zhou,Zhonghua Liu,Shuguang Zhang
Hunan black tea is well-known for its floral-honey aroma, but the volatile components responsible for the fragrance have not been elucidated yet. In this study, the volatile compounds in Hunan black tea were identified and quantified by the headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that 88 compounds were extracted and determined in Hunan black tea, including the dominant components Geraniol, phenethyl alcohol, phenylacetaldehyde, linalool, nonanal and other 5 aromatic compounds. Furthermore, the aroma-active compounds were identified by odor activity value (OAV). It was found that 24 aroma compounds, including geraniol with an OAV≥1 were regarded as the primary active aromatic compounds in Hunan black tea. Finally, partial least squares (PLS) regression analysis was employed and results revealed that Nonanal, trans -nerolidol, benzyl alcohol, and phenylethanol exhibit a positive correlation with the intensity of floral and sweet honey aromas. Overall, this study identified the volatile compounds responsible for the dominant floral-honey aroma in Hunan black tea.
✓ 已验证
产品关联
DOI
高影响因子
Food Bioscience
·
2022
·
IF 5.318
Xiaoye Lan,Zhibin Liu,Daoliang Wang,Sijia Zhan,Wensong Chen,Weiying Su,Yaqian Sun,Li Ni
Due to the premium flavor, Qingxin oolong tea (QOT), which is grown and produced in Taiwan, is widely appreciated. Roasting is a crucial process for shaping its flavor. However, the effect of roasting on the aroma and taste of QOT was not fully understood. In this study, the volatile composition, aroma-active compounds and phenolic profile of QOT with different roasting degrees, including the unroasted (UR), the medium roasted (MR) and the heavy roasted (HR) were analyzed. As revealed by headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and multivariate statistical analyses, UR and MR demonstrated similar volatile profiles, while heavy roasting changed the volatile composition greatly. Multiple nitrogen-containing compounds, such as 3,5-diethyl-2-methylpyrazine and 2-ethyl-3,5-dimethylpyrazine, were uniquely found in heavy roasted samples, which can be ascribed to the extensive Maillard reaction . Moreover, eight compounds were identified and verified as key aroma-active compounds by using gas chromatography-olfactometry-mass spectrometry (GC-O-MS), aroma recombination and omission experiments. The aldehydes and alcohols, such as linalool, benzeneacetaldehyde and α-farnesene, with a floral scent were the dominant aroma-active compounds in UR and MR, while 2-ethyl-3,5-dimethylpyrazine and 3,5-diethyl-2-methylpyrazine with a roasted scent were the main aroma-active compounds in HR. Furthermore, as revealed by ultra-high performance liquid chromatography and Orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap-MS), flavanols and phenolic acids were significantly lower in abundance in UR and MR as compared to those in HR, whereas flavonols were less affected by roasting. These findings provide useful information for understanding the flavor characteristics of this popular oolong tea for the first time.
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Wei Zhou,Xin Wang,Youping Liu,Weikang Zhang,Xin Di
In this work, a magnetic halloysite nanotubes composite material modified with polydopamine (MHNTs@PDA) was synthesized through a facile and green synthesis strategy, and employed as an efficient adsorbent for magnetic solid-phase extraction (MSPE) of three anthraquinones. The material showed very fast adsorption ability (adsorption time of 3 min), good reusability and strong magnetic response. The main parameters affecting the extraction efficiency of MSPE, including adsorption time, amounts of adsorbent, sample pH, salt concentration and desorption conditions, were investigated and optimized. By coupling MHNTs@PDA-based MSPE with HPLC-UV, the method exhibited good linearity (R 2 ≥ 0.9944) in the concentration range of 5–1000 μg L -1 and low limits of detection (1.0–1.5 μg L -1 ) for anthraquinones. Finally, the developed method was successfully applied to determine anthraquinones in brewed slimming tea, and the obtained recoveries were in the range of 73.5–119.1%, with RSD less than 9.7%.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 30
·期 15
·42575-42586
·
IF 5.19
Appu Manikandan,Wu Huixiang,Chen Hao,Huang Jianying
In the present study, we hypothesized that novel nanocomposites of chitosan-coated cerium oxide (CS/CeO 2 NCs) derived from aqueous extracts of tea polyphenols would be stabilized and reduced by using green chemistry. The UV–visible spectrum of the synthesized material revealed an SPR peak at 279 nm, and the morphological characteristics of nanoparticles (NPs) as a uniformly distributed spherical shape with a size range of 20 nm were confirmed by field emission scanning electron microscopy (FESEM). The Fourier transform infrared spectroscopy (FTIR) spectrum illustrated the amino groups of chitosan-coated with CeO 2 NPs on the surface. While, the hydrodynamic size (376 nm) and surface charge (+ 25.0 mV) of particles were assessed by dynamic light scattering (DLS), and the existence of oxidation state elements Ce 3d, O 1 s, and C 1 s was identified by employing X-ray photoelectron spectroscopy (XPS). A cubic fluorite polycrystalline structure with a crystallite size of (5.24 nm) NPs was determined using an X-ray Diffractometer (XRD). The developed CS/CeO 2 NCs demonstrated excellent antibacterial and antifungal efficacy against foodborne pathogens such as Escherichia coli , Staphylococcus aureus , and Botrytis cinerea with zone of inhibition of 13.5 ± 0.2 and 11.7 ± 0.2 mm, respectively. The results elucidated the potential of biosynthesized CS/CeO 2 NCs could be utilized as potent antimicrobial agents in the food and agriculture industries.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
npj Science of Food
·
2022
·Vol. 6
·期 1
·1-8
·
IF 7
Chen Yu-Hong,Zhang Yan-Hong,Chen Gen-Sheng,Yin Jun-Feng,Chen Jian-Xin,Wang Fang,Xu Yong-Quan
Phenolic acids are important taste components in green tea. The aim of this study was to analyze the taste characteristics of phenolic acids and their influence on the bitterness and astringency of green tea by sensory evaluation and chemical determination. The major tea phenolic acids and quercetin-3- O -rutinoside (Que-rut) were significantly positively correlated with the bitterness ( r = 0.757, p < 0.01; r = 0.605, p < 0.05) and astringency ( r = 0.870, p < 0.01; r = 0.576, p < 0.05) of green tea infusion. The phenolic acids have a sour and astringent taste, whereas Que-rut has a mild astringent taste. Phenolic acids and Que-rut can increase the bitterness of epigallocatechin gallate (EGCG). However, these components behaved differently for astringency on EGCG. Gallic acid (GA) enhances the astringency throughout all the concentrations in this study. While it seemed to be double effects of caffeic acid (CA), chlorogenic acid (CGA), and Que-rut on that, i.e., the inhibition at lower concentrations (CA: 0–0.2 mM; CGA: 0–0.2 mM; Que-rut: 0–0.05 mM) but enhancement at higher ones. The phenolic acids and Que-rut interacted synergistically with tea infusion and as their concentration increased, the synergistic enhancement of the bitterness and astringency of tea infusion increased. These findings help provide a theoretical basis for improving the taste of middle and green tea.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2022
·
IF 9.879
Xiaohui Guo,Yuanfang Luo,Lijuan Chen,Bowen Zhang,Yongjun Chen,Demin Jia
To achieve simultaneous environment protecting, high-efficiency rubber antioxidant is still an enormous and long-term challenge in green rubber industry. Hence, a novel biomass antioxidant (denoted as silica-s-TP) was obtained by silica supported with green tea polyphenols exhibited prominent anti-aging functionality. Silica-s-TP hybrid particles were uniformly dispersed in rubber matrix with remarkable interfacial interaction , and the high-efficiency free radical capturing activity was stem from the construction of polyphenol structure on silica surface. Therefore, silica-s-TP brought to simultaneously enhance the performance of anti-aging property of SBR composites and surpass the achievements of the commercial antioxidants. Interesting, the biomass antioxidant silica-s-TP exhibited remarkable free radical-scavenging activities and stability in SBR matrix than the TP directly added in SBR matrix, due to the chemical anchor TP on silica surface. Such clay surface treatment technology with natural antioxidant may also bring to a new path for the preparation of green and eco-friendly functionalization rubber additives.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD SCIENCE
·
2021
·Vol. 86
·期 10
·4262-4274
·
IF 3.167
Hui Xue,Meng Xu,Guowen Zhang,Feng Feng,Yuting Wang,Danhui Cao,Yonggang Tu,Yan Zhao
This study aimed to investigatethe mechanism of stewing with tea polyphenols (TP) on the properties of boiled egg white gel (BEWG). The results indicated that, during the stewing process, soluble protein and hardness showed an overall increasing trend, while surface hydrophobicity showed a decreasing trend with blue-shift. The free sulfhydryl group showed that TP could promote the formation of disulfide bonds, and the position of immobilized water at T 2 showed a decreasing trend. Environmental scanning electron microscopy and SDS-PAGE showed that the protein gel aggregation degree increased. Moreover, Fourier transform infrared spectrometry showed that protein polarity increased and that α-helices, β-turn, intramolecular β-sheets, as well as intermolecular antiparallel β-sheets showed an increasing trend. Generally, TP strengthened protein aggregation by promoting the formation of disulfide and hydrogen bonds, thus enhancing the gel strength of BEWG. Moreover, the secondary structure of proteins became more stable under the action of TP, and the higher the concentration of TP, the greater the effect on BEWG. Practical Application TP, an ideal, cheap, and safe natural food additive, can be applied to the processing of egg products because the addition of TP can significantly improve the gel strength of egg white.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2020
·
IF 7.246
Fukang Deng,Tao Jiang,Kedi Yang,Fuchuan Huang
Developing an eco-friendly and energy efficient lubricant additive is important in the field of tribology . Herein, we successfully synthesized a series of green and efficient lubricant additives by grafting the n-carbon alkyl chain to tea saponin (TSCn, n = 8,10,12,14,16), nano tribofilm can self-assemble on sliding surfaces in both water and oil phases. Low frequency and high contact stress ball-on-disc reciprocating friction tests showed that TSC14 and TSC16 exhibit excellent lubricating performance. When 0.5 wt% of TSC14/TSC16 was added in DI water, the friction coefficient and wear rate were reduced by 67.69%/69.74% and 79.42%/81.65%, respectively. When 0.5 wt% of TSC14/TSC16 was added in PAO6, the friction coefficient and wear rate were reduced by 46.15%/42.86% and 86.19%/80.48%, respectively. In addition, the TSC14/TSC16 emulsion also exhibited good stability and lubricity.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）