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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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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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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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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Analytical Methods
·
2019
·Vol. 11
·期 38
·4923-4930
·
IF 2.378
Heng Qian,Chaoran Liu,Qian Yang,Xinya Liu,Haixiang Gao,Wenfeng Zhou
Deep eutectic solvents (DESs), which consist of a mixture of hydrogen bond acceptor and hydrogen bond donor compounds, were used in liquid-phase microextraction, in which the extractant was dispersed in a porous ceramic film for the determination of pyrethroid pesticides in juice and tea beverage samples. Factors affecting recovery were optimized individually, which included salt addition, surfactant addition, extraction temperature, DES amount and sample volume. Based on the results of an optimized experiment, the recovery of pyrethroid pesticides is from 87.5% to 97.2% with relative standard deviation (RSD) values ranging from 1.68% to 2.86%. Determination coefficient was from 0.9981 to 0.9997 and the linear range was between 1.5 μg L−1 and 500 μg L−1. Based on a signal-to-noise ratio (S/N) of 3 : 1, the limit of detection (LOD) values were 0.45 μg L−1 to 1.30 μg L−1. The enrichment factor ranged from 93 to 106. For real samples, bifenthrin is found in black tea (Gold rougui) and oolong tea (Tieguanyin2); etofenprox is also found in the oolong tea (Tieguanyin3). In spiked samples, good extraction efficiency was achieved for all types of samples analyzed under the optimized conditions.
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JOURNAL OF SEPARATION SCIENCE
·
2019
·Vol. 42
·期 8
·1610-1619
·
IF 2.516
Chaoran Liu,Xinya Liu,Philip J. Marriott,Heng Qian,Zilin Meng,Zhirong Yang,Runhua Lu,Haixiang Gao,Wenfeng Zhou
In this work, a method for the analysis of benzoylurea insecticides, including hexaflumuron, flufenoxuron, lufenuron and chlorfluazuron, in tea samples by high-performance liquid chromatography with Fe 3 O 4 -hyperbranched polyester nanocomposite as the adsorbent for magnetic solid-phase extraction was developed. The magnetic nanocomposite was prepared and characterized by infrared spectroscopy, vibrating sample magnetometry, and scanning electron microscopy. The as-prepared nanocomposite was used as a sorbent for the extraction and preconcentration of pesticide residues in tea samples. The extraction and desorption conditions, including mass ratios of raw materials, amount of sorbent, pH value, extraction time, and desorption time, were investigated. Under the final conditions chosen for the analysis, good linearity was obtained for all the tested compounds, with R 2 values of at least 0.9979. The limits of detection were determined in the range of 0.15–0.3 μg/L. The recovery obtained from the analysis of tea samples with various spiked concentrations was between 90.7 and 98.4%, with relative standard deviations (n = 4) lower than 4.1%. Furthermore, the present approach was successfully applied to the quantitative determination of residues of benzoylurea insecticides in real samples.
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FOOD CHEMISTRY
·
2018
·
IF 4.946
Ying Zhou,Qiyuan Peng,Ling Zhang,Sihua Cheng,Lanting Zeng,Fang Dong,Ziyin Yang
1-Phenylethanol is a chiral flavor compound that has enantiomers, ( R )- and ( S )-1-phenylethanol, with different flavor properties. Given that isolating these enantiomers from plants is low yielding and costly, enzymatic synthesis presents an alternative approach. However, the genes/enzymes that specifically produce ( R )- and ( S )-1-phenylethanol in plants are unknown. To identify these enzymes in tea ( Camellia sinensis ) flowers, 21 short chain dehydrogenase (SDR) genes were isolated from tea flowers, cloned, and functionally characterized. Several recombinant SDRs in Escherichia coli exhibited activity for converting acetophenone to ( S )-1-phenylethanol (CsSPESs, >99.0%), while only one SDR produced ( R )-1-phenylethanol (CsRPES, 98.6%). A pair of homologue enzymes (CsSPES and CsRPES) showed a strong preference for NADPH cofactor, with optimal enzymatic reaction conditions of 45–55 °C and pH 8.0. Identification of the tea flower-derived gene responsible for specific synthesis of ( R )- and ( S )-1-phenylethanolsuggests enzymatic synthesis of enantiopure 1-phenylethanol is possible using a plant-derived gene.
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Food Analytical Methods
·
2016
·Vol. 9
·期 12
·3298-3309
·
IF 2.167
Wang Chao,Zhang Chen-Xia,Shao Chun-Fu,Li Chang-Wen,Liu Shun-Hang,Peng Xiao-Pei,Xu Yong-Quan
A simple and efficient fingerprint analysis method was developed and validated for the quality consistency control and authentication of Deepure instant pu-erh tea within different manufacturers using high-performance liquid chromatography (HPLC) coupled with chemometrics. To compare the HPLC fingerprint chromatograms between batches, varieties and manufacturers, the correlation coefficients of similarities of 60 samples and the relative peak areas of 11 characteristic compounds were calculated. Different pattern recognition procedures, including hierarchical cluster analysis, principal component analysis and partial least squares discriminant analysis, were then applied to classify the instant pu-erh tea samples according to their variety and manufacturer. Results showed that the developed method has potential application for the quality consistency evaluation and discrimination of instant pu-erh tea samples from similar products.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2016
·
IF 2.857
Yu-Chun Wang,Wen-Jun Qian,Na-Na Li,Xin-Yuan Hao,Lu Wang,Bin Xiao,Xin-Chao Wang,Ya-Jun Yang
Tea plant (Camellia sinensis) is one of the most economically valuable crops in the world. Anthracnose can affect the growth of leaves and cause serious yield losses of tea. Tea plants are rich in secondary metabolites; however, their roles in resistance to anthracnose are unclear. Herein we compared the contents of total phenolics, catechins, and caffeine in two cultivars with different resistances to anthracnose during Colletotrichum fructicola infection. (−)-Epigallocatechin-3-gallate (EGCG), (+)-catechin (C), caffeine, and critical regulatory genes were induced in C. fructicola-resistant tissues. In vitro antifungal tests showed that caffeine more strongly inhibited mycelial growth than tea polyphenols and catechins. Both electron microscopy and bioactivity analysis results showed that caffeine can affect mycelial cell walls and plasma membranes. Through promoter sequences analysis, a number of stress response-related cis-acting elements were identified in S-adenosylmethionine synthetase and tea caffeine synthase. These results demonstrated that (−)-EGCG, (+)-C, and caffeine may be involved in the resistance of tea plants to anthracnose.
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INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
·
2024
·
IF 2.6
Xudong Xia,Rongrui Lu,Nanxing Zhao,Hongming Kong,Fang Yuan,Hesheng Liu,Lianliang Liu,Xiangyang Qi,Qiuping Chen
Summary α-Glycosidase, a critical therapeutic target in type 2 diabetes mellitus (T2DM), can be modulated by inhibitors to reduce postprandial blood glucose levels. This study investigated the inhibitory effects of vine tea ( Ampelopsis grossedentata ) and its key compounds on α-glycosidase. The results demonstrated that fifteen varieties of vine tea extracts inhibited α-glycosidase in a dose-dependent manner, with IC 50 values ranging from 5.25 to 35.8 μg mL −1 . HPLC analysis revealed dihydromyricetin (DHM) as the main compound in vine tea, with an IC 50 value of 262.50 μM. Notably, the synergistic combination of DHM and the antidiabetic drug acarbose (ABS) significantly enhanced inhibitory effectiveness, with the optimal ratio (1:125) yielding a potentiation index (CI) of 0.09. Fluorescence and molecular docking analyses supported the hypothesis that DHM enhanced ABS's inhibitory effect through complex formation and specific interactions, offering a promising option for safer and more effective diabetes therapy.
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BIOLOGY OF REPRODUCTION
·
2024
·
IF 3.1
Shi Heng,Zhao Xin-Hai,Peng Qin,Zhou Xian-Ling,Liu Si-Si,Sun Chuan-Chuan,Cao Qiu-Yu,Zhu Shi-Ping,Sun Sheng-Yun
Di(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer known for its toxic effects on the male reproductive system. Green tea polyphenols (GTPs), recognized for their antioxidant and anti-inflammatory properties, have demonstrated protective effects on various organs, but the mechanisms by which GTPs mitigate DEHP-induced testicular damage remain unclear. Healthy male C57BL/6J mice were divided into five groups: control, DEHP, DEHP + GTP treatment, GTP, and oil groups. Testicular histopathological changes were assessed using hematoxylin–eosin (H&E), periodic acid-Schiff (PAS), and Masson staining. Ultrastructural alterations were examined through transmission electron microscopy. High-throughput sequencing was performed to analyze the expression of mRNA, miRNA, and lncRNA and construct an lncRNA–miRNA–mRNA regulatory network for identifying key regulatory axes. Mice in the DEHP group exhibited significant testicular damage, including reduced sperm count, mitochondrial deformation, and endoplasmic reticulum dilation. GTP treatment notably improved testicular structural integrity, restored sperm count, and alleviated mitochondrial and endoplasmic reticulum damage. Additionally, DEHP significantly increased activated CD8+ T cells, which were reduced with GTP treatment. High-throughput sequencing revealed that GTP treatment exerted protective effects through the regulation of six key lncRNA–miRNA–mRNA axes. GTPs significantly protect against DEHP-induced testicular damage, and the lncRNA–miRNA–mRNA regulatory axes play a potential role in this process.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Mengli Chen,Zhanyi Xu,Guoxing Chen,Peitong Chen,Chunxia Tian,Jiali Qian,Tiefeng Song,Yongfeng Jin,Guonian Zhu,Ru Yan
Numerous essential oils have been well acknowledged as eco-friendly alternatives to combat insect pests due to synthetic insecticide-induced pest resistance and environment pollution. As a highly commercial essential oil, tea tree oil exhibits excellent insecticidal and repellent activities. However, the molecular mechanism of the olfactory system mediating the tea tree oil-induced repellency against insect pests remains unknown. In our study, mosquito was used as a suitable model to examine the molecular mechanism of tea tree oil-induced repellency against insect pests. The results showed that tea tree oil exhibited excellent spatial and oviposition repellency against Aedes aegypti adults and outstanding repellency against larvae, which were conferred by the main constituent terpinen-4-ol. The reduced repellency in the Orco–/– mutant strain revealed that tea tree oil-induced repellency against mosquitoes was dependent on odorant receptor(s). Moreover, we identified one antenna-biased odorant receptor, AaOr96, that was involved in detecting constituents of tea tree oil to elicit repellency, and the predicted protein–ligand complex indicated that AaOr96 interacted with terpinen-4-ol via van der Waals forces from five key residues. Finally, knocking out AaOr96 resulted in a reduced spatial repellency against A. aegypti by tea tree oil and terpinen-4-ol, and a reduced oviposition repellency by terpinen-4-ol, but not by tea tree oil. Our study not only reveals that tea tree oil has great potential in pest management but also provides more insights into the molecular basis of repellency of essential oils.
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