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Dark tea

Yuwan Wang, Mingyue Zhang, Zhengzhu Zhang, Hengqian Lu, Xueling Gao, Pengxiang Yue
BACKGROUND: Theabrownins (TB) are bioactive components usually extracted from Chinese dark tea, where they are present in low concentrations. This study aimed to produce an instant dark tea high in theabrownins via submerged fermentation by the fungus Aspergillus niger. Three fermentation parameters that affect theabrownins content, namely inoculum size, liquid-solid ratio and rotation speed, were optimized using response surface methodology. RESULT: Optimum fermentation conditions were modeled to be an inoculum of 5...
April 19, 2017: Journal of the Science of Food and Agriculture
Ana Gabriela Murillo, Maria Luz Fernandez
The chemical structure of polyphenols consisting of aromatic rings, capable of quenching free radicals, makes them ideal candidates to protect against oxidation. Polyphenols are present in a variety of foods including grapes, berries, dark chocolate, coffee and tea to mention a few. A number of studies have shown that dietary polyphenols exert a protective effect against hypertension, dyslipidemias, inflammation, endothelial function and atherosclerosis, conditions associated with increased risk for cardiovascular disease...
March 29, 2017: Current Pharmaceutical Design
Wu-Xia Bai, Chao Wang, Yijun Wang, Wen-Jun Zheng, Wei Wang, Xiaochun Wan, Guan-Hu Bao
A novel acylated flavonol tetraglycoside, kaempferol 3-O-[(E)-p- coumaroyl-(1→2)][α-L-arabinopyranosyl-(1→3)][β-D-glucopyranosyl (1→3)-α-L- rhamnopyranosyl (1→6)]-β-D-glucopyranoside (camellikaempferoside C, 1), together with two flavonol and eighteen flavone and flavonol glycosides (FGs) (2-21) was isolated from the green tea Lu'an GuaPian (Camellia sinensis L.O. Kuntze). Their structures were identified by spectroscopic and chemical methods. Four acylated FGs (1, 7, 8, 9) were found to inhibit the proliferation and differentiation of 3T3-L1 preadipocytes at the concentrations 25, 50, 100 µM (P < 0...
March 24, 2017: Journal of Agricultural and Food Chemistry
Ichiro Kuriki, Ryan Lange, Yumiko Muto, Angela M Brown, Kazuho Fukuda, Rumi Tokunaga, Delwin T Lindsey, Keiji Uchikawa, Satoshi Shioiri
Despite numerous prior studies, important questions about the Japanese color lexicon persist, particularly about the number of Japanese basic color terms and their deployment across color space. Here, 57 native Japanese speakers provided monolexemic terms for 320 chromatic and 10 achromatic Munsell color samples. Through k-means cluster analysis we revealed 16 statistically distinct Japanese chromatic categories. These included eight chromatic basic color terms (aka/red, ki/yellow, midori/green, ao/blue, pink, orange, cha/brown, and murasaki/purple) plus eight additional terms: mizu ("water")/light blue, hada ("skin tone")/peach, kon ("indigo")/dark blue, matcha ("green tea")/yellow-green, enji/maroon, oudo ("sand or mud")/mustard, yamabuki ("globeflower")/gold, and cream...
March 1, 2017: Journal of Vision
Yin Zhu, Chen-Yang Shao, Hai-Peng Lv, Yue Zhang, Wei-Dong Dai, Li Guo, Jun-Feng Tan, Qun-Hua Peng, Zhi Lin
Volatile terpenoids play important roles in the formation of tea aroma quality due to their pleasant scents and low odor thresholds. Most volatile terpenoids contain stereogenic centers, which results in various stereo distributions of their enantiomers and diastereoisomers in different types of tea. However, the distribution characteristics of terpenoid enantiomers in teas were still unclear, which poses an obstacle to the scientific understanding of tea aroma. In this work, a new and efficient analysis approach based on headspace solid phase microextraction (HS-SPME)-chiral gas chromatography-mass spectrometry (GC-MS) was established to analyze 12 pairs of familiar terpenoid enantiomers in different teas...
February 10, 2017: Journal of Chromatography. A
Yiyong Chen, Xiumin Fu, Xin Mei, Ying Zhou, Sihua Cheng, Lanting Zeng, Fang Dong, Ziyin Yang
Shade management (dark treatment) on tea (Camellia sinensis) plants is a common approach to improve free amino acids in raw materials of tea leaves. However, the reason for amino acid accumulation in dark-treated tea leaves is still unknown. In the present study, dark treatment significantly increased content of free amino acids and reduced content of soluble proteins in tea leaves. Quantitative proteomics analysis showed that most enzymes involved in biosyntheses of amino acids were down-accumulated by dark treatment...
March 22, 2017: Journal of Proteomics
K K Huber-van der Velden
The term "luxury foodstuffs" refers to foods which are not consumed because of their nutritional value. Classic modern luxury foodstuffs are alcohol, caffeine-containing drinks, cocoa, sugar and tobacco. The following review article examines some of these modern luxury foodstuffs in detail, as well as their influence on glaucoma. Thus, small quantities of alcohol lower high intraocular pressure and have a positive influence on the blood circulation of the optic nerve. In addition, red wine polyphenols exert vasoprotective effects...
February 2017: Klinische Monatsblätter Für Augenheilkunde
Longqing Shi, Liette Vasseur, Huoshui Huang, Zhaohua Zeng, Guiping Hu, Xin Liu, Minsheng You
Insect behaviors are often influenced by light conditions including photoperiod, light intensity, and wavelength. Understanding pest insect responses to changing light conditions may help with developing alternative strategies for pest control. Little is known about the behavioral responses of leafhoppers (Hemiptera: Cicadellidae) to light conditions. The behavior of the tea green leafhopper, Empoasca onukii Matsuda, was examined when exposed to different light photoperiods or wavelengths. Observations included the frequency of locomotion and cleaning activities, and the duration of time spent searching...
2017: PloS One
Jianyang Zhang, Guicen Ma, Liyan Chen, Ting Liu, Xin Liu, Chengyin Lu
Puerh tea, as the most representative Chinese dark tea, has attracted global interest in recent years. Profiling the levels of metal elements in Puerh tea is very important since its presence is related to human health. In this study, 41 elements in 98 Puerh tea samples from Yunnan province, China including Puerh raw tea and Puerh ripe tea were evaluated by microwave digestion combined with Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The content of toxic elements, essential elements and rare earth elements of Puerh tea from different regions was discussed in detail...
January 9, 2017: Food Additives & Contaminants. Part B, Surveillance
Jianyu Fu, Haipeng Lv, Feng Chen
Chinese dark teas (CDTs) are now among the popular tea beverages worldwide due to their unique health benefits. Because the production of CDTs involves fermentation that is characterized by the effect of microbes, microorganisms are believed to play critical roles in the determination of the chemical characteristics of CDTs. Some dominant fungi have been identified from CDTs. In contrast, little, if anything, is known about the composition of bacterial community in CDTs. This study was set to investigate the diversity and variation of bacterial community in four major types of CDTs from China...
2016: PloS One
Shuyuan Liu, Zhi Yu, Hongkai Zhu, Wei Zhang, Yuqiong Chen
BACKGROUND: Natural products have being used as potential inhibitors against carbohydrate-hydrolyzing enzymes to treat diabetes mellitus. Chinese dark tea has various interesting bioactivities. In this study, the active compounds from Qingzhuan dark tea were separated and their anti-diabetic activity was examined using an in vitro enzymatic model. METHODS: The chloroform, ethyl acetate, n-butanol, sediment and residual aqua fractions of a Chinese dark tea (Qingzhuan tea) were prepared by successively isolating the water extract with different solvents and their in vitro inhibitory activities against α-glucosidase were assessed...
September 29, 2016: BMC Complementary and Alternative Medicine
Valerio Sanguigni, Melania Manco, Roberto Sorge, Lucio Gnessi, Davide Francomano
OBJECTIVE: The formation of reactive oxygen species (ROS) contributes to the pathogenesis and progression of several diseases. Polyphenols have been shown to be beneficial against ROS. The aim of this study was to evaluate the effects of a natural antioxidant ice cream on oxidative stress, vascular function, and physical performance. METHODS: In this controlled, single-blind, crossover study, 14 healthy individuals were randomized to consume 100 g of either antioxidant ice cream containing dark cocoa powder and hazelnut and green tea extracts or milk chocolate ice cream (control ice cream)...
January 2017: Nutrition
Marla Hahn, Marília Baierle, Mariele F Charão, Guilherme B Bubols, Fernanda S Gravina, Paulo Zielinsky, Marcelo D Arbo, Solange Cristina Garcia
This review aimed to investigate possible protective or deleterious effects of polyphenol-rich foods (PRF) on chronic diseases, e.g. cardiovascular, and in pregnant women, along with their antioxidant and anti-inflammatory action. A great variety of foods and beverages, such as herbal teas, grape and orange derivatives, dark chocolate, and many others contain high concentrations of flavonoids and are freely consumed by the general population. In humans, PRF consumption reduces lipid peroxidation, and several studies have shown a positive correlation between an increased consumption of PRF and a decrease in the incidence of cardiovascular disease...
August 7, 2016: Drug and Chemical Toxicology
Sara Wickham
In this column, Sara Wickham takes a sideways look at issues relevant to midwives, students, women and families, inviting us to sit down with a cup of tea and ponder what we think we know. As it is always useful to consider how we can facilitate physiological labour and birth, this month Sara shares some of the tips that she has gathered from midwives and other birth workers about how they help women and families to lower the light levels and create the semi-darkness which many people feel is conducive to normal birth...
March 2016: Practising Midwife
Justyna Brzezicha-Cirocka, Małgorzata Grembecka, Piotr Szefer
This study concerns application of flame atomic absorption spectrometry (FAAS) in assessment of macro- and microelement and toxic metal levels (Mg, Ca, K, Na, Mn, Cu, Fe, Zn, Cr, Ni, Co, Cd and Pb) in dark (Pu-erh) and fruit tea leaves and their infusions. Phosphorus was also determined in the form of phosphomolybdate by spectrophotometric method. The reliability of the method was checked using three certified reference materials. The results of analysis were in agreement with the certified values, with analytical recovery ranging from 86 to 113 %...
November 2016: Biological Trace Element Research
Yun-Song Lai, Sha Li, Qian Tang, Huan-Xiu Li, Shen-Xiang Chen, Pin-Wu Li, Jin-Yi Xu, Yan Xu, Xiang Guo
Recently, we developed a novel tea cultivar 'Ziyan' with distinct purple leaves. There was a significant correlation between leaf color and anthocyanin pigment content in the leaves. A distinct allocation of metabolic flow for B-ring trihydroxylated anthocyanins and catechins in 'Ziyan' was observed. Delphinidin, cyanidin, and pelargonidin (88.15 mg/100 g FW in total) but no other anthocyanin pigments were detected in 'Ziyan', and delphinidin (70.76 mg/100 g FW) was particularly predominant. An analysis of the catechin content in 'Ziyan' and eight other cultivars indicated that 'Ziyan' exhibits a preference for synthesizing B-ring trihydroxylated catechins (with a proportion of 74%)...
April 6, 2016: Journal of Agricultural and Food Chemistry
Yong-Zhen Tian, Xiao Liu, Wen Liu, Wei-Yun Wang, Yan-Hua Long, Liang Zhang, Yan Xu, Guan-Hu Bao, Xiao-Chun Wan, Tie-Jun Ling
Fuzhuan brick-tea (FBT) is unique for a fungal fermentation stage in its manufacture process and is classified in dark tea. A new acylated flavonol glycoside, kaempferol 3-O-[E-p-coumaroyl-(→2)][α-l-arabinopyranosyl-(1→3)][α-l-rhamnopyranosyl(1→6)]-β-d-glucopyranoside, which was trivially named as camellikaempferoside A (1), was isolated from FBT along with camelliquercetiside C (2). Their structures were unambiguously elucidated by combination of spectroscopic and chemical methods. Compound 1 showed anti-proliferative activity against MCF-7 and MDA-MB-231 cells with IC50 values of 7...
February 17, 2016: Natural Product Research
Elżbieta Rusinek-Prystupa, Zbigniew Marzec, Iwona Sembratowicz, Wioletta Samolińska, Bożena Kiczorowska, Małgorzata Kwiecień
The study aimed to determine the content of selected elements: sodium, potassium, copper, zinc, iron, manganese and active ingredients such as phenolic acids and tannins in teas containing Yerba Mate and Rooibos cultivated in various areas. The study material comprised six samples of Yerba Mate teas and of Rooibos teas, both tea bags and leaves, purchased in Puławy and online via Allegro. In total, 24 samples were tested. Yerba Mate was particularly abundant in Mn and Fe. The richest source of these elements was Yerba Mate Yer-Vita (2261...
July 2016: Biological Trace Element Research
Xiumin Fu, Yiyong Chen, Xin Mei, Tsuyoshi Katsuno, Eiji Kobayashi, Fang Dong, Naoharu Watanabe, Ziyin Yang
Regulation of plant growth and development by light wavelength has been extensively studied. Less attention has been paid to effect of light wavelength on formation of plant metabolites. The objective of this study was to investigate whether formation of volatiles in preharvest and postharvest tea (Camellia sinensis) leaves can be regulated by light wavelength. In the present study, in contrast to the natural light or dark treatment, blue light (470 nm) and red light (660 nm) significantly increased most endogenous volatiles including volatile fatty acid derivatives (VFADs), volatile phenylpropanoids/benzenoids (VPBs), and volatile terpenes (VTs) in the preharvest tea leaves...
2015: Scientific Reports
Fan Zhu, Ratchaneekorn Sakulnak, Sunan Wang
Black tea is rich in phenolic antioxidants and has various health benefits. Chinese steamed bread (CSB) is a traditional food produced through steaming of fermented dough. Black tea extracts were incorporated into northern style CSB formulation at varying concentrations up to 175mg gallic acid equivalent/gram of wheat flour. Gelatinization properties of wheat flour were not affected by the black tea addition. Rheological analysis of wheat flour showed that black tea increased pasting viscosity, consistency index of flow curves, and storage modulus (G') and loss modulus (G″) during dynamic oscillation...
March 1, 2016: Food Chemistry
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