TOTAL FLAVONOID CONTENT OF COMMONLY CONSUMED TEAS IN INDIA (original) (raw)
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Study of flavonoids and phenolic acids in green tea leaves
Current issues in pharmacy and medicine: science and practice, 2021
The aim of work is study qualitative composition and quantitative content of flavonoids and phenolic acids in green tea leaves. Material and methods. The object of the study was green tea leaves, which were collected in Anhui Province, China. The analysis of 60 % ethanolic extract from green tea leaves was performed by high-performance liquid chromatography using a Prominence LC-20 Shimadzu chromatographic system (Japan) with an SPD-20AV spectrophotometric detector, an Agilent Technologies Microsorb-MV-150 column (reversed-phase, C18 modified silica gel, length – 250 mm, diameter – 4.6 mm, particles size – 5 μm). Identification of substances in the extract was carried out by comparing the retention time and the spectral characteristics of the test substances with the same characteristics of the reference standards. Results. 13 compounds were identified and determined by high-performance liquid chromatography. Among flavonoid aglycones quantitatively dominated by quercetin (0.35 %),...
Proceedings of the International Conference on Health Informatics and Medical Application Technology, 2019
The utilization of natural resources that contain antioxidants is in high demand by the community to prevent degenerative diseases such as heart disease, diabetes, stroke and cancer. Processing of Dayak onion and beet root in the form of herbal tea has great potential to be used as a functional drink because both of these plants contain flavonoids which have antioxidant properties. In 5 tea formulas made by comparing the composition of Dayak onions and beet root, a preference test was conducted on several panelists related to color, aroma and taste and obtained 3 formulas favored by the panelists are formula1, 3 and 4. the purpose of this study was to determine the total flavonoid levels of each of the teabag formulas favored by panelists using the UV Visible spectroprotometry method with a quercetin comparison. From the research conducted obtained linear regression equation data y = 0.0364x + 0.0028 with r = 0.997. Total flavonoid levels for each teabag combination of dayak onion a...
Tea is the most common and popular beverage next to water across the globe due to its taste, aroma and neutraceutical importance. In the present investigation six commercial varieties of black and green tea were analyzed for their total phenolic content using uv-visible spectrophotometer.. The amounts of phenols were determined with the Folin-Ciocalteu reagent method. Gallic acid was used as standard compound and the total phenols were expressed as mg/g of gallic acid equivalents. Total phenol varied in the range of 77.44 ± 0.18 mg/g to 102.68 ± 0.12 mg/g.The maximum phenolic content was found in green tea infusion (102.68 ± 0.12 mg/g).The results shown that all tea samples tested found to contain comparable high total phenolics as rich sources of bioactive compounds and it justifies their use for human health benefits.
Particle size, heating time and heating method are important factors affecting the yield of an extraction process. This study aims to determine the total concentrations of phenolic compounds and flavonoids as well as their antioxidant activity in 37 samples (12 loose and 25 commercial branded tea powders) by different extraction methods. Our results show that among the different extraction methods used for polyphenols and flavonoids, the microwave assisted extraction (MAE) method gives the best results. In 1 min, MAE shows significantly higher extraction than water-bath extraction for 15 min, ultrasound-assisted extraction for 15 min and brewing extraction for 5 min. Microwave extraction shows high efficiency in extraction while using a minimum amount of solvent, shorter extraction time, ease of maintenance of extraction vessels and the enhancement of recovery and repeatability. During the study we found that extraction of polyphenols and flavonoids from the tea powder has two important limiting factors which affect its estimation namely, the particle size and the time for which heat is supplied. Tea powder samples were divided into five classes A, B, C, D and E using different Indian standard sieve meshes (4mm, 2mm, 1mm and 0.5mm) to vary particle size. The duration and method of supplying heat were varied. It was generally found that greater the surface area more is the extractability. In case of tea powder, however, the processes by which the tea sample have been prepared is also significantly affects the extraction. INTRODUCTION Tea, the second most popular beverage after water, is known for its variety of flavours and aromas. It is prepared from the apical leaves and buds of Camellia sinensis (L.) Kuntze. Tea infusion is widely used as a medicine by tribal people throughout India and China. It is also extensively used in various indigenous system of medicine like Ayurveda (Parmar et al., 2012). Different types of teas, produced using various processes, are known all over the world. Six types of teas that are most widely known are black (regular), green, yellow, white, oolong and reprocessed tea. The processing of the six types of teas depends on the physical and biological characteristics of young tea shoots (Ruan, 2005). Importance of Polyphenols in Food Polyphenols, predominantly flavonoids and phenolic acids, that are present in tea in large quantities act as micronutrients in our diet and contribute significantly to the flavour and health-enhancing properties. Their importance in the prevention of degenerative diseases is rapidly gaining importance. Plant polyphenols comprise a great variety of compounds, among which flavonoids and several classes of non-flavonoids are usually distinguished. Dietary polyphenols show an enormous assortment of structures, ranging from simple molecules (monomers and oligomers) to polymers (Lung et al., 2013). Plant phenolics are increasingly being shown to retard the oxidative degradation of lipids and thereby improve the quality and nutritional value of food.
Phytochemical Density of Some Promising Commercial Tea Brands
International Journal of Food Properties, 2012
Black Tea (Camellia sinensis) is an important source of phytochemicals with proven health benefits. The core objective of the present investigation was to characterize some promising commercial tea brands available in Pakistan for their active ingredients with special reference to flavanols. The results indicated that total phenolic contents were in the range of 26.42 to 29.74 g/100 g liquid tea, while antioxidant activity and DPPH reduction was in the range from 45 to 50 g/100 g liquid tea and 47 to 50 g/100 g liquid tea, respectively. Tea quality parameters including theaflavins, thearubingins, and theabronins were observed to be 1.71–1.79, 1.74–1.83, and 17.05–20.22 g/100 g liquid tea. Likewise, total catechins and caffeine were 1.01–1.28 and 1.22–1.25 g/100 g liquid tea, respectively. Tea extract of commercial brands containing a larger particle size exhibited better quality.
Qualitative and quantitative evaluation of flavanols in Green tea [Camellia sinensis (L) O Kuntze]
The Pharma Innovation Journal, 2017
Plants are commonly used in treating or preventing specific ailments or diseases and are playing valuable role in health care. Probably, around 60% of world’s population is relying on medicinal plants for their primary healthcare. Bioactive plant extracts are considered as a promising source of biological friendly antibacterial agents. The relationship between the quality and chemical components in green tea have been studied, and have shown that free amino acids, caffeine and polyphenols are qualitatively important components. Especially, catechins, the main component of polyphenols, are well known for their antioxidant properties, which have led to their evaluation in many diseases associated with free radicals. Significant seasonal variations of phenolic content were observed. The order of variations of flavan-3-ols was (–)-epigallocatechin gallate > (–)-epigallocatechin > (–)-epicatechin gallate > epicatechin > (+)-catechin.
Journal of Agricultural and Food Chemistry, 2002
Rooibos tea originates from the leaves and stems of the indigenous South African plant Aspalathus linearis. It has gained much attention for clinical purposes in the case of nervous tension, allergies (dermatitis), and various indigestive problems. Recently, antioxidative activity was also attributed to the tea on the basis of its flavonoid content. Therefore, an HPLC method using a C 18 reversed phase column was developed for the assay of 10 flavonoids in aqueous and methanolic infusions. Main compounds determined were the dihydrochalcone aspalthin, rutin, and orientin, and their content was in the range of 1.0 to 1.3 mg/g. The identity of detected flavonoids was confirmed by comparing their retention times and UV and MS spectra with those of corresponding standards. In addition, the MS analysis showed evidence of the presence of other compounds such as nothofagin, dihydroisoorientin, and dihydroorientin.
Determination of flavonoids in tea and Rooibos extracts by TLC and HPLC
JPC - Journal of Planar Chromatography - Modern TLC, 2008
In this study thin-layer chromatography (TLC) was used for analysis of the constituents of extracts of tea (Camellia sinensis L.) and Rooibos (Aspalathus linearis) leaves. In particular, flavonoids, a group of phenolic compounds, for example myrecetin, rutin, catechin, quercetin, and kaempferol were analyzed. Extracts of various types of tea, for example black, green, and Rooibos herbal tea (called red tea) were analyzed. The efficiency of extraction of flavonoids from plant material by classical liquid extraction (LE) and supercritical-fluid extraction (SFE) was also compared. Recoveries of individual flavonoids were approximately ten times higher after use of solvent extraction. Separation of flavonoids from tea extracts on the basis of their polarities was optimized by selection of solvents, stationary phases, and chromatographic conditions. For final analyses glass-backed silica gel 60 F 254 plates and the mobile phase acetone-chloroform-water 80:20:10 (v/v) were used. UV detection of TLC chromatograms (254 and 366 nm) was used. Better detection of the flavonoids was achieved at 366 nm. The concentration of some important flavonoids in real tea samples was obtained by high-performance liquid chromatography (HPLC).
Journal of Food Composition and Analysis, 2005
Data in the food composition analytical literature were reviewed. They were then aggregated and assembled into a provisional database for the major flavonoids in brewed tea. As levels of fermentation increased from green to oolong to black tea, the major flavan-3-ol profiles changed. Total catechins were 13.6 g/100 g in green and 4.2 g/100 g dry weight in black tea. A discussion of methods to calculate the flavonoid content in tea is presented.
Journal of Agricultural and Food Chemistry, 2002
Rooibos tea originates from the leaves and stems of the indigenous South African plant Aspalathus linearis. It has gained much attention for clinical purposes in the case of nervous tension, allergies (dermatitis), and various indigestive problems. Recently, antioxidative activity was also attributed to the tea on the basis of its flavonoid content. Therefore, an HPLC method using a C 18 reversed phase column was developed for the assay of 10 flavonoids in aqueous and methanolic infusions. Main compounds determined were the dihydrochalcone aspalthin, rutin, and orientin, and their content was in the range of 1.0 to 1.3 mg/g. The identity of detected flavonoids was confirmed by comparing their retention times and UV and MS spectra with those of corresponding standards. In addition, the MS analysis showed evidence of the presence of other compounds such as nothofagin, dihydroisoorientin, and dihydroorientin.