JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2013
·
IF 2.906
Lihua Jiang,Xiaojia Shen,Toshihiko Shoji,Tomomasa Kanda,Jiachun Zhou,Liming Zhao
Zijuan tea is a new cultivar produced in Yunnan province of China. Unlike most tea cultivars, Zijuan tea is anthocyanin-rich. The composition and antioxidant activities of anthocyanins of Zijuan tea were studied for the first time in this paper. Anthocyanins were extracted with acidified methanol and quantified as 707 ± 28 μg/g of dry weight (cyanidin-3-O-β-d-glucoside equivalent) by high-performance liquid chromatography (HPLC) analysis. Four anthocyanins were successfully identified after Amberlite XAD-7HP adsorption column chromatography and octadecyl silane (ODS) flash chromatography. Among the four, delphinidin-3-O-β-d-galactoside (1) and cyanidin-3-O-β-d-galactoside (2) were confirmed by liquid chromatography–electrospray ionization mass spectrometry (LC-ESI-MS) and HPLC. Delphinidin-3-O-β-d-(6-(E)-p-coumaroyl) galactopyranoside (3) and cyanidin-3-O-β-d-(6-(E)-p-coumaroyl) galactopyranoside (4) were characterized by the high-resolution time-of-flight-mass spectrometry (HRTOF-MS) and nuclear magnetic resonance (NMR) spectrometry. The antioxidant activities of compounds 3 and 4, which composed approximately 75% of the total anthocyanins content in HPLC analysis, were evaluated by DPPH and FRAP assays. Results showed that both had higher antioxidant activities than commercial antioxidants butylated hydroxytoluene (BHT) used as one of controls in these assays.
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Food & Function
·
2014
·Vol. 5
·期 7
·1520-1528
·
IF 2.907
Ye-wei Huang,Huan-huan Xu,Su-min Wang,Yi Zhao,Yu-min Huang,Run-bo Li,Xuan-jun Wang,Shu-mei Hao,Jun Sheng
Caffeine is present in a number of dietary sources consumed worldwide. Although its pharmacokinetics has been intensively explored, little is known about complexed caffeine (C-CAF) in aqueous extraction of fermented Pu-er tea. The major components of C-CAF are oxidative tea polyphenols (OTP) and caffeine. Furthermore, the C-CAF can be precipitated in low pH solution. After administering the same amount of total caffeine and comparing the peak level of plasma caffeine with the coffee (contains 0.11 ± 0.01% C-CAF) group, the results showed that the caffeine/OTP (contains 66.67 ± 0.02% C-CAF) group and the instant Pu-er tea (contains 23.18 ± 0.02% C-CAF) group were 33.39% and 25.86% lower, respectively. The concentration of the metabolites of caffeine supports the idea that the absorption of the C-CAF was inhibited in mice. Congruent with this result, the amount of caffeine detected in mice excrement showed that more caffeine was eliminated in the caffeine/OTP group and the Pu-er tea group. The locomotor activity tests of mice demonstrated that the stimulating effect of caffeine in caffeine/OTP and Pu-er tea was weaker than in coffee. Our findings demonstrate that caffeine can be combined with OTP and the absorption of C-CAF is inhibited in mice, thus decreasing the irritation effect of caffeine. This may also be developed as a slow release formulation of caffeine.
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MOLECULES
·
2016
·Vol. 21
·期 10
·1345
·
IF 2.465
Meng Shi,Ying Nie,Xin-Qiang Zheng,Jian-Liang Lu,Yue-Rong Liang,Jian-Hui Ye
Ultraviolet B (UVB) photosensitivities of eight catechins were screened. In both water and ethanol, epicatechin (EC, 575 μM) and catechin (C, 575 μM) exhibited low photostabilities under 6 h UVB radiation with the generation of yellow photoproducts, while other catechins (epigallocatechin gallate, epigallocatechin, epicatechin gallate, gallocatechingallate, gallocatechin, catechin gallate) were relatively UVB-insensitive. Photoisomerization and photolysis were two important UVB-induced reactions to EC whereas photolysis was the dominant reaction for C. The influencing factors of time (2–10 h), solvent (water, ethanol) and substrate concentration (71.875–1150 μM) on UVB-induced chemical conversions of EC and C were investigated, and eight photoproducts were identified through ultra performance liquid chromatography-diode array detection-tandem mass spectrometry (UPLC-DAD-MS/MS) and1H nuclear magnetic resonance (1H-NMR analysis). Photolysis reaction involved two pathways, including radical reaction and photo-induced electron transfer reaction. The 2,2-diphenylpicrylhydrazyl (DPPH) scavenging abilities of eight catechins did not change upon 6 h UVB irradiation. EC and C are photosensitive catechins among eight catechins causing deep color.Keywords:photostability;catechins;photoisomerization;photolysis;photoproducts
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Foods
·
2025
·Vol. 14
·期 6
·941
·
IF 5.1
Wenxue Chen,Jiezhong Zan,Linfeng Yan,Haibo Yuan,Peiqiang Wang,Yongwen Jiang,Hongkai Zhu
Tea blending technology is based on finished tea. Blending fresh leaves during processing has not been proposed and investigated anywhere. This study investigates the impact of blending fresh leaves from different varieties on the flavor quality of black tea. The main taste components, including catechins, theaflavins, and free amino acids, were analyzed using HPLC, while the volatile components were analyzed using GC-MS. The results show that adding freshJinguanyinorJinxuanleaves toFudingdabaican regulate the ratio of esterified to non-esterified catechins, increase the content of theaflavins and amino acids, and positively impact the strength and freshness of the black tea. The sensory evaluation results show that the taste scores of FJG (black tea made from the blend of freshFudingdabaiandJinguanyintea leaves) (92.14 ± 0.41 b) and FJX (black tea made from the blend of freshFudingdabaiandJinxuantea leaves) (93.80 ± 0.19 a) are significantly higher than those ofFudingdabai(90.05 ± 0.31 d),Jinguanyin(86.10 ± 0.45 e), andJinxuan(91.03 ± 0.26 c). Furthermore, adding freshJinguanyinorJinxuanleaves toFudingdabaican also enhance the floral compounds in the black tea, specifically phenylacetaldehyde, linalool, benzyl alcohol, and oxidized linalool (linalool-type pyran), which make important contributions to the floral aroma of the black tea. Conclusions: Blending fresh leaves for processing can enhance the sensory quality of black tea. This work proposes new insights and methods to enhance black tea sensory quality via the blending of fresh tea leaves with different varieties during processing.
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JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2024
·
IF 4
Xiaoyan Shen,Xiaofen Wu,Hui Qi,Dongning Wei,Ming Deng,Keqin Wang,An Liu,Liang Chen
This study focused on the efficiency of enzymatic synthesis for theaflavins (TFs) and SII types of thearubigins (SII-TRs) in suspended fermentation of different varieties of tea leaves. The results showed that the content of catechins in tea variety-Xiaoxianghong 21-3 (XXH21-3) was the highest among the five kinds of fresh tea leaves, and it had the strongest ability of transforming catechins to TFs and SII-TRs. The total amount of catechins for XXH 21-3 decreased rapidly and the conversion ratio of TFs reached the highest level of 13.96% after 20 min, the residual catechins was the lowest (3.08%) and the conversion rate of SII-TRs was the highest (13.02%) after 120 min during the suspended fermentation of five varieties tea leaves. Among the six catechin types, epicatechin gallate (ECG), epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were consumed in large quantities, and the residues were all less than 5% in the final stage of fermentation, of which ECG consumption was the fastest, followed by EGCG. These results demonstrated that the concentration of catechins and PPO activities were positively correlated with the formation of TFs and SII-TRs, POD activity was positive correlation with synthesis of SII-TRs and negative correlation with TFs.
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FOOD CHEMISTRY
·
2024
·
IF 8.5
Yueming Liang,Zhusheng Liu,Yuelan Pang,Min Li,Shengmeng Zheng,Fujing Pan,Chunyu Guo,Qianhua Wu,Ting Chen,Qiang Li,Zhonghua Liu
Long-term storage of Liupao tea is conducive to improving its flavour and commercial value. Although bacterial communities influence Liupao tea flavour, their impact during storage remains unclear. The aroma compounds and bacterial communities were determined by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC–MS) and Illumina Nova6000 analysis. A total of 18 differential flavour compounds were significantly altered with Liupao tea storage duration, particularly after 9 years of storage. Flavour compounds with sweet notes increased, while those associated with pungent note decreased. The composition and diversity of bacteria remarkable changed after 9 years of tea storage. Six core functional bacteria were identified as contributing to the flavour characteristics of Liupao tea during long-term storage. Our findings provide novel insights that bacteria drive the formation of flavour characteristics during Liupao tea storage duration, and Liupao tea stored for more than 9 years have the best flavour.
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Current Research in Food Science
·
2024
·
IF 6.2
Yufei Zhang,Yanyin Lu,Dandan Pan,Yanyan Zhang,Chen Zhang,Zexin Lin
Despite lignocellulose hindering the extraction of intracellular components, tea residue can serve as an excellent substrate for fungal fermentation owing to their lignocellulose-degrading abilities. Thus, the fermentation efficiencies of Lentinus edodes , Lentinus sajor-caju (Fr.) , Flammulina filiformis , Hericium erinaceus , Pleurotus pulmonarius , and Monascus kaoliang B6 were evaluated using tea residue as a medium. P. pulmonarius and L. sajor-caju (Fr.) exhibited the fastest growth rates, with colony radii of 33.1 and 28.5 mm, respectively. M. kaoliang B6 demonstrated substantial degradation abilities for cellulose, hemicellulose, and lignin, with decolorization radii of 12.2, 0.9, and 8.5 mm, respectively. After a 9-days liquid fermentation, M. kaoliang B6 achieved the highest conversion efficiency at 27.8%, attributed to its high cellulase (191 U∙mL −1 ) and lignin peroxidase (36.9 U∙L −1 ) activities. P. pulmonarius and L. sajor-caju (Fr.) showed lower conversion rates of 8.6% and 3.8%, despite having high hemicellulase activities (67.1 and 70.9 U∙mL −1 ). Fermentation by M. kaoliang B6 resulted in a reduction of protein and total sugar content in the tea residue by 174 and 192 mg g −1 , by which the mycelium's protein and total sugar content increased by 73 and 188 mg g −1 . Co-fermentation of these three strains had little effect on the improvement of conversion efficiency, which might owe to the antagonistic interactions among the strains. Generally, utilizing tea residue for edible fungi fermentation is a sustainable process for bio-waste treatment, enabling efficient nutrient conversion under mild conditions without adding chemicals.
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Heliyon
·
2024
·
IF 3.4
Huazhen Huo,Aihua Cai,Yunchang Xie,Chunyu Guo
Purpose Piling is a critical process for the formation of raw Liupao tea (RLT) flavor quality. However, given the unclear changes in the flavor quality of RLT during the piling process, and the key substances of taste-contributing and aroma components that affecting the flavor quality of RLT was lacking. Herein, the present study aimed at evaluating the changes in flavor quality and its key substances of RLT during the piling process. Methods Sensory evaluation was conducted on RLT samples collected at 11 time points during the piling process. The biochemical and aroma components of these samples were detected using UV spectrophotometer, high-performance liquid chromatography (HPLC), and headspace solid-phase microextraction gas chromatography–mass spectrometer (HS-SPME-GC-MS), respectively. Multivariate analysis was performed to investigate the effects of piling time on the flavor quality of RLT. Key findings The sensory quality of RLT increased and then decreased during the piling process. The changes in flavor quality of RLT during the piling process could be divided into four stages: 0–6, 9–15, 18–24, and 27–30 h. The flavor quality of RLT changed significantly with the variations in biochemical and volatile compounds. The key contributors to taste changes included significant decreases in (−)-epigallocatechin gallate, (−)-epicatechin gallate, (−)-epigallocatechin, (−)-catechin gallate, and theobromine content and significant increases in gallic acid, gallocatechin, and theaflavin content. Additionally, alterations in the content of 19 characteristic aroma compounds, such as cedrol, methyl salicylate, methyl palmitate, trans-nerolidol, decanal, 6,10-Dimethyl-2-undecanone, neryl alcohol, α -cedrene, and (E, E)-2,4-heptadienal, significantly influenced the aroma of the tea infusion. This study provides insights into the formation of flavor quality in RLT at different piling stages, which also provide a scientific foundation for optimizing the piling and production processes of RLT.
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Frontiers in Nutrition
·
2024
·
IF 4
Shi Yuxuan,Guo Shasha,Zhou Jihong,Xu Ping,Wang Yuefei
Introduction: Black tea, a beverage consumed worldwide, possesses favorable effects on gastrointestinal tract, including nourishing stomach and promoting digestion. Nevertheless, its specific effects on intestinal homeostasis remains inconclusive.Methods: We applied black tea to mice prior to inducing colitis with DSS and then monitored their body weight and disease activity index (DAI) daily. When sacrificed, we measured intestinal permeability and conducted analyses of mucin and tight junction proteins. We detected inflammatory cytokines, immune cells, and related inflammatory signaling pathways. In addition, the gut microbiota was analyzed through 16S rRNA sequencing, and the concentrations of short-chain fatty acids (SCFAs) were also measured.Results: The results showed that black tea-treated group significantly rescued the DSS-disrupted intestinal structure. It reduced the relative abundance of the pathogenic bacterium Turicibacter, while increased the abundance of beneficial bacteria norank_f_Muribaculaceae and restored the contents of SCFAs such as acetate, propionate, and butyrate. It also protected the intestinal barrier by reducing the levels of immune response-related factors (e.g., TNF-α, IL-6, IL-1β) and increasing the expression of tight junction proteins (TJs) (e.g., ZO-1, occludin). Furthermore, black tea exhibited the capacity to suppress the expression of MMP-9 and ICAM-1, as well as to inhibit the activation of NF-κB signaling pathway.Discussion: Our findings provide a theoretical framework that elucidates the mechanisms by which black tea preserves intestinal homeostasis, highlighting its potential as a preventive strategy against intestinal disruptions. This study contributes to the understanding of the dietary effects of black tea on gastrointestinal health.
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Food and Bioprocess Technology
·
2024
·
IF 5.3
Gao Weilan,Zheng Zhan,Chen Rongyu,Zhang Na,Wang Xuehua,Zhu Zhenzhou,Li Shuyi,Cong Xin
Selenylation modification is an effective way to improve the nutritional and health effects of tea polysaccharide, but the effects of different selenylation methods on the structure and efficacy of polysaccharides remain unclear. In this study, a series of chemically selenized tea polysaccharides (CSe-TPS, selenium content of 129.98 ~ 1454.99 µg/g) were prepared by Na 2 SeO 3 -HNO 3 method, which were promoted by heating (HCSe-TPS), ultrasound (UCSe-TPS), and pulse electric field (PCSe-TPS) treatments, respectively. These different CSe-TPSs were systematically compared with ordinary tea polysaccharides (Ord-TPS) and natural selenium-enriched tea polysaccharides (NSe-TPS) in aspect of molecular structure and biological functions. The results of molecular structure and apparent morphology showed that the particle size ( p < 0.05) and the thermal stability of Ord-TPS were reduced after selenylation modification, while the absolute potential of polysaccharide was increased ( p < 0.05), coupled with altered monosaccharide composition and changed apparent morphology. However, the main functional groups and the secondary structure of Ord-TPS did not change. The antioxidant activities of tea polysaccharides after selenylation were improved as well as their inhibitory effects on carbohydrate digestive enzymes ( p < 0.05). The total antioxidant capacity of PCSe-TPS (selenium content of 240.66 ± 1.43µmol/g) was enhanced by 85.41% compared with Ord-TPS (selenium content of 129.80 ± 3.42 µmol/g), while its IC 50 values on inhibition of α-amylase (2.91 ± 0.18 mg/mL) and α-glucosidase (0.18 ± 0.01 mg/mL) were significantly lower than other tea polysaccharides ( p < 0.05), which suggested best antioxidant and hypoglycemic activity. Moreover, tea polysaccharides with higher selenium content and smaller particle size showed better antioxidant and hypoglycemic activities. This research will provide new strategies for the application of tea polysaccharides.
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Pharmaceuticals
·
2024
·Vol. 17
·期 9
·1181
·
IF 4.3
Zeting Huang,Lanyue Zhang,Jie Xuan,Tiantian Zhao,Weihua Peng
Atopic dermatitis (AD) is a persistent and recurrent inflammatory skin condition with a genetic basis. However, the fundamental reasons and mechanisms behind this phenomenon remain incompletely understood. While tea extracts are known to reduce histamine-induced skin allergies and inflammation, the specific mechanisms by which various types of Chinese tea provide their protective effects are still not fully elucidated. In this study, a model of skin itching induced by histamine is used to explore the functions and mechanisms of three types of tea extract (Keemun black tea (HC), Hangzhou green tea (LC), and Fujian white tea (BC)) in alleviating histamine-induced dermatitis. The components of three tea extracts are identified by UPLC-Q-TOF-MS, and we found that their main components are alkaloids, fatty acyls, flavonoids, organic acids, and phenols. The inhibitory effects of three types of tea extract onEscherichia coli(E. coli) andStaphylococcus aureus(S. aureus) in skin injury are investigated by MIC and flow cytometry. The three types of tea extract have an inhibitory effect on the growth of bacterial flora, with HC showing the best inhibitory activity. The effect of the three types of tea extract on histamine-induced dermatitis is also evaluated. Furthermore, itchy skin experiments, HE staining, toluidine blue staining, and immunohistochemical staining of mouse skin tissues were performed to determine the variations of scratching, epidermal thickness, mast cell number, IL-1β, and NGF content after the administration of the tea extracts. The three types of tea extracts all alleviate and inhibit skin itching, epidermal hyperplasia, and allergic dermatitis. BC effectively alleviates epidermal hyperplasia caused by skin allergies, and LC significantly downregulates NGF. HC reduces histamine-induced mast cell infiltration and downregulates IL-1β to alleviate skin itching. Consequently, tea emerges a potent natural product that can inhibit the growth of skin wound bacterial flora and exhibit skin repair effects on histamine-induced allergic dermatitis.
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Food Chemistry-X
·
2024
·
IF 6.5
Maiquan Li,Yunxia Dong,Mangjun Kang,Tiantian Tao,Wenlan Li,Sheng Zhang,Wei Quan,Zhonghua Liu
Hyperglycemia can cause early damage to human bady and develop into diabates that will severely threaten human healthy. The effectively clinical treatment of hyperglycemiais is by inhibiting the activity of α-amylase. Black tea has been reported to show inhibitory effect on α-amylase and can be used for hyperglycemia treatment. However, the mechanism underlying is unclear. In this study, in vivo experiment showed that black tea theaflavins extract (BTE) effectively alleviated hyperglycemia. In vitro experiment showed that the effects may be caused by the interation between theaflavins and α-amylase. While TF1 and TF3 were mixed type inhibitors of α-amylase, TF2A and TF2B were competitive inhibitors of α-amylase. Molecular docking analysis showed that theaflavins monomers interacted with the hydrophobic region of α-amylase. Further study verified that monomer-α-amylase complex was spontaneously formed depending on hydrophobic interactions. Taken together, theaflavins showed potential anti-hyperglycemia effect via inhibiting α-amylase activity. Our results suggested that theaflavins might be utilized as a new type of α-amylase inhibitor to prevent and cure hyperglycemia.
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