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.
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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
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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.
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FOOD CONTROL
·
2021
·
IF 5.548
Yan-mei Shi,Li-qin Chao,Lin Mei,Zhi-hong Chen,Xiu-min Li,Ming-san Miao
Herein, a soluble tetramine phthalocyanine indium-decorated reduced graphene oxide (rGO-InTAPc) nanocomposite was prepared via non-covalent functionalization and used to construct a novel electrochemical sensor for sensitive determination of rutin in Tartary buckwheat tea. The rGO-InTAPc as an improved electrode material can significantly increase the electroactive surface area and electron transfer capacity. Moreover, the electrochemical response can be dramatically expanded by the enrichment effect of rutin through the adsorption of π-π stacking. Under optimized conditions, the rGO-InTAPc sensor displayed a linear dependence for rutin concentration ranging from 0.005 to 100 μM with a detection limit of 2.0 nM ( S/N = 3). The proposed sensor with excellent selectivity and reproducibility was quantitatively validated in commercially available Tartary buckwheat tea with rutin level ranging of 9.06–13.87 mg/g, which results were highly consistent with these of HPLC. This strategy of rutin detection will address a long-standing analytical challenge to establishing facile and sensitive methods for quality monitoring in tea drinks.
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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.
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Ruimin Wang,Ruiping He,Zhaohui Li,Songjie Li,Congfa Li,Lu Wang
Herein, high efficient extraction of natural antioxidants from partridge leaf-tea (PLT) was carried out by using eco-friendly choline chloride-based deep eutectic solvents combined with ultrasonic method. Choline chloride-malic acid (ChCl-MaA), a new type of green solvent, with the highest efficient for extracting the natural antioxidants from PLT (DPPH -756.70 ± 12.13 μmol TE/g DW; FRAP-4139.17 ± 65.79 μM Fe(Ⅱ)SE/g DW) was screened for further optimization. The key parameters for simultaneously maximizing total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhyldrazyl (DPPH ) and ferric reducing antioxidant activity (FRAP) were optimized by single-factor experiments along with response surface methodology (RSM). Results exhibited that L/S ratio and water content in DES had significant effects on TPC and antioxidant activities, while ultrasonic power indicated a significant negative effect on all responses. Under the optimal conditions (ultrasonic power at 210 W, ultrasonic time at 30 min, L/S ratio at 27.50:1, water content in DES at 45%), experimentally obtained results were obtained as follows: 42.20 ± 2.17 mg GAE/g DW for TPC, 30.33 ± 2.16 mg RE/g DW for TFC, 838.64 ± 12.81 μmol TE/g DW for DPPH , and 5958.33 ± 153.52 μM Fe(Ⅱ)SE/g DW for FRAP, which were well in agreement with the predicted values. Furthermore, ChCl-MaA-based ultrasonic assisted extraction (UAE) yielded higher TPC, TFC and antioxidant activities compared with traditional solvents-based UAE. Strong antioxidant activities of PLT extracts were correlated with high levels of individual antioxidants including salvianic acid A, 3-chlorogenic acid, gallic acid, catechin and rutin. The functional groups analysis by Fourier transform infrared spectroscopy (FT-IR) were used to compare the solvents characterization before and after extraction. Scanning electron microscope (SEM) results further verified ChCl-MaA intensified the destruction of cell wall structure, and thereby allowed greater release of antioxidants from PLT. This work provides an eco-friendly ChCl-MaA-based UAE technique for efficiently extraction and valorization of phenolic compounds from PLT, which can be further used in pharmaceutical, food, and cosmetic industries.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Zhenming Wang,Junyu Chang,Qi Hu,Hui Zhi,Liang Feng
To improve the sensing performance of the traditional semiconductor sensor towards triethylamine (TEA), the poly(diallyldimethylammonium chloride) (PDDA) has been applied to functionalize the reduced graphene oxide (rGO), which has been further decorated by the polyaniline (PANI) nanocones via an in-situ polymerization method. The existence of PDDA during the synthetic process could efficiently prevent the restacking of rGO and promote the reduction of graphene oxide, which is beneficial for producing uniform PANI nanocones on the rGO sheets and improving the sensitivity to TEA. The sensor fabricated by the PDDA-rGO-PANI has exhibited excellent sensing performance to the TEA with superior sensitivity, stability and selectivity at room temperature. The sensor possesses a perfect linear coefficient of 0.999 from 2 to 100 ppm TEA and an extremely low limit-of-detection (LOD) of 74 ppb. In addition, the sensor has presented an outstanding anti-interference ability against humidity, other interfering gases (ammonia and common VOCs) and even mechanical bending. Finally, a self-powered sensing system containing a homemade triboelectric nanogenerator (TENG), a commercial flexible electrode, a button battery and the integrated circuit LTC3588 has been fabricated. The size of TENG is only 3.5×3.5 cm 2 while the sensing system after integrated on a PI membrane is just 2×4 cm 2 , which makes the sensor a promising potential candidate of wearable sensing to TEA in daily life.
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高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2020
·
IF 4.192
Jingming Wang,Na Zhang,Minyue Zhao,Tingting Jing,Jieyang Jin,Bin Wu,Xiaochun Wan,Wilfried Schwab,Chuankui Song
The carotenoid-derived volatile β-ionone plays an important role in the formation of green and black tea flavors due to its low odor threshold, but its formation and the gene(s) involved in its biosynthesis during the tea withering process is(are) still unknown. In this study, we found that the content of β-ionone increased during the tea withering process catalyzed by an unknown enzyme(s). Correlation analysis of expression patterns of Camellia sinensis carotenoid cleavage dioxygenase genes (CsCCDs) and the β-ionone content during the withering period revealed CsCCD4 as the most promising candidate. The full-length CsCCD4 gene was amplified from C. sinensis, and the biochemical function of the recombinant CsCCD4 protein was studied after coexpression in Escherichia coli strains engineered to accumulate β-carotene. The recombinant protein was able to cleave a variety of carotenoids at the 9–10 and 9′–10′ double bonds. Volatile β-ionone was detected as the main product by gas and liquid chromatography–mass spectrometry. The accumulation of β-ionone was consistent with the expression levels of CsCCD4 in different tissues and during the withering process. The CsCCD4 expression was induced by low temperature and mechanical damage stress but not by dehydration stress. The results demonstrate that CsCCD4 catalyzes the production of β-ionone in the tea plant and provide insight into its formation mechanism during the withering process.
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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.
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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.
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PubMed
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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.
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高影响因子
MOLECULES
·
2023
·Vol. 28
·期 15
·5889
·
IF 4.6
Yue Zhu,Teng Chen,Tingting Feng,Jiaojiao Zhang,Zejing Meng,Ning Zhang,Gang Luo,Zuhua Wang,Yuxin Pang,Ying Zhou
Nanoemulsion is a new multi-component drug delivery system; the selection of different oil phases can give it special physiological activity, and play the role of “medicine and pharmaceutical excipients all-in-one”. In this paper, we used glycyrrhizic acid as the natural surfactant, andBlumea balsamiferaoil (BB) and tea tree oil (TTO) as the mixed oil phase, to obtain a new green functional composite nanoemulsion. Using the average particle size and polydispersion index (PDI) as the evaluation criteria, the effects of the oil ratio, oil content, glycyrrhizic acid concentration, and ultrasonic time on the nanoemulsion were systematically investigated. The stability and physicochemical properties and biological activities of BB-TTO NEs prepared via the optimum formulation were characterized. The optimal prescription was BB: TTO = 1:1, 5% oil phase, 0.7% glycyrrhizic acid, and 5 min ultrasonication time. The mean particle size, PDI, and zeta potential were 160.01 nm, 0.125, and −50.94 mV, respectively. The nanoemulsion showed non-significant changes in stability after centrifugation, dilution, and 120 days storage. These nanoemulsions were found to exhibit potential antibacterial and anti-inflammatory activities. The minimal inhibitory concentration (MIC) of BB-TTO NEs againstEscherichia coli,Staphylococcus aureus, andPseudomonas aeruginosais 2975 μg/mL, 2975 μg/mL, and 5950 μg/mL, respectively. A lower level of inflammatory cell infiltration and proportion of fibrosis were found in the synovial tissue of AIA rats treated with BB-TTO NEs. These findings demonstrate that the BB-TTO NEs produced in this study have significant potential for usage in antibacterial and anti-inflammatory areas.Keywords:nanoemulsion;Blumea balsamiferaoil;tea tree oil;glycyrrhizic acid;anti-inflammatory;antibacterial
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高影响因子
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