Turbidimetric and photometric determination of total tannins in tea using a micro-flow-batch analyzer

Lima, Marcelo B.; Andrade, Stéfani Iury E.; Harding, David P.; Pistonesi, Marcelo Fabián; Band, Beatriz Susana Fernández; Araújo, Mário César Ugulino de

doi:10.1016/j.talanta.2011.11.076

Cited by 19 publications

(13 citation statements)

References 29 publications

(44 reference statements)

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“…Tannins are found in foods and beverages, especially in green and black tea. They confer acidity and astringency to wine and a variety of drinks [39,40]. Although the tannin content was not determined in this study, M. indica has been reported to contain gallotannins [41], suggesting that teas made from its leaves contain certain amounts of these compounds, which may be related to the acidity, astringency and bitterness of these beverages.…”

Section: Physicochemical Characterization Of the Teamentioning

confidence: 66%

Extraction of Mangiferin and Chemical Characterization and Sensorial Analysis of Teas from Mangifera indica L. Leaves of the Ubá Variety

et al. 2016

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Abstract:Mangiferin is present in various parts of Mangifera indica L. and has proven biological activities, such as antioxidant capabilities. The aim of this work was to evaluate the chemical composition of teas prepared from M. indica leaves, their potential use as a source of mangiferin and their total phenolic compounds. Teas were prepared with young and mature leaves of M. indica at three (medicinal plant: solvent) ratios utilizing three different preparation techniques. The mangiferin content was analyzed via high-performance liquid chromatography (HPLC). The tea with the highest mangiferin content was characterized for its total phenolic content and antioxidant activity. The oxidative stability was also evaluated by quantifying mangiferin, total phenolics and antioxidant activity using two preservation treatments for 0, 24 and 48 h. Sensory analysis was performed to measure the acceptance of the tea. The type of leaf, preparation technique and concentration influenced the mangiferin content in the teas. The highest concentration of mangiferin was obtained through decoction at a 5% (w/v) medicinal plant concentration. This tea exhibited stability up to 48 h after preparation under both preservation treatments and provided a positive sensory acceptance for consumers with flavors added. In conclusion, teas made from M. indica leaves have great potential as sources of mangiferin and phenolic compounds.

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Section: Physicochemical Characterization Of the Teamentioning

confidence: 66%

Extraction of Mangiferin and Chemical Characterization and Sensorial Analysis of Teas from Mangifera indica L. Leaves of the Ubá Variety

et al. 2016

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“…We obtained a high speed of analysis, thanks to the optimizations in the addition times and volumes of the fluids, in a microsystem that allowed a homogenization efficient and discrete measurements. Although the proposed system has been applied only to samples of green tea, the ferrous tartrate method can be also applied, in the same DIB-μFBA, for other types of tea, such as black tea, oolong tea, and white tea, where the tannin may vary between 10 and 100 mg L −1 [26][27][28][29][30][31].…”

Section: Resultsmentioning

confidence: 99%

“…The ferrous tartrate method is more selective than the Folin-Ciocalteau method [25] and is unaffected by the coexistence of reducing agents, such as ascorbic acid [26]. It is being used by researchers for the spectrophotometric determination of tannins in tea [27][28][29][30][31][32].…”

Section: Introductionmentioning

confidence: 99%

A digital image-based micro-flow-batch analyzer

Lima

Andrade

Barreto

et al. 2013

Microchemical Journal

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This paper introduces for the first time the combination of digital images taken with a webcam and a microflow-batch analyzer as a novel strategy for implementing quantitative chemical analysis. The digital imagebased micro-flow-batch analyzer (DIB-μFBA) was formed using urethane-acrylate resin, glass slides and ultraviolet lithography. The glass slides were used as sealant layers on both sides of the substrate urethane-acrylate and provide the necessary transparency to the microsystem to conduct studies using digital images. DIB-μFBA uses digital images obtained from a webcam with CCD sensor, based on the RGB (red-green-blue) color model. The analyzer was used for determining the tannins in green tea employing the well-known ferrous tartrate method. All standard solutions were prepared in-line, and all analytical processes were completed by simply changing the operational parameters in DIB-μFBA control software. The paired t test, at a 95% confidence level, showed no statistically significant differences between results obtained by DIB-μFBA and the spectrophotometric reference method. The proposed microsystem presented satisfactory physical and chemical properties while keeping the flexibility, versatility, robustness and multi-task characteristics of conventional flow-batch analysis. Therefore, it was possible to build a low-cost device with high sample throughput (about 190 h −1 ) and reduced reagent consumption (about 300 times less than the reference method), contributing to the basic principles of green chemistry and the advancement of micro-analytical procedures.

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“…The concentration of these compounds as shown in this study correlates to the significant antioxidant activity of the plant as reported earlier 18 . Tannins are a polyphenol group with high molecular weights and in general possess antioxidant, anticarcinogenic, antimutagenic and antimicrobial activities and it can also assist in the prevention and treatment of diseases 35 . Saponins are glycosides of both triterpenes and sterols and have rich pharmaceutical importance.…”

Section: Discussionmentioning

confidence: 99%

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2013

IJPSR

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Lippia nodiflora L. is an important medicinal plant of Verbenaceae family and are used traditionally for several ailments. The present study deals with the detailed physicochemical, fluorescence and phytochemical evaluation of aerial parts of Lippia nodiflora L., in order to explore the authentic plant material suitably for its traditional claims. The physicochemical evaluations and fluorescence analysis were determined as per standard protocols. Phytochemical constituents of dried plant material were carried out by both qualitative and quantitative methods. Gas Chromatography-Mass Spectrometry (GC-MS) was used to analyze the phytochemical constituents of the methanol extract. Analysis of physicochemical parameters of the powdered aerial parts showed that total ash was approximately two times more than water insoluble ash and alcohol soluble extractive value was higher than water soluble extractive value. Preliminary phytochemical screening showed the positive result for the presence of flavonoids, steroids, glycosides, alkaloids, terpenoids, tannins and phenolics. Quantitative analysis showed that the methanolic extract consist of high phenolic compounds (98.31 ± 0.004 mg GAE/g) followed by total flavonoids (60.88 ±0.001mg QE/g) and flavonols (27.46 ± 0.002 mg QE/g). Total tannin and saponin content was found to be 5.97 ± 0.021mg TAE/g and 3.52 ± 0.017mg DE/g respectively. The major chemical components of methanolic extract of L. nodiflora determined by GC-MS were 2, 7-dioxatricyclo [4.3.1.0 (3, 8)] decan-4-one (35.75%), stigmasterol (16.86%), benzoic acid, 4-etoxy-, ethyl ester (13.73%), azacyclotridecan-2one (11.86%) and n-hexadecanoic acid (10.12%). The results of the present study provide preliminary referential information of the plant and also serve as an investigative tool for the appropriate identification. The presence of various chemical constituents suggests that this plant exhibit rich phytopharmaceutical importance.

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Turbidimetric and photometric determination of total tannins in tea using a micro-flow-batch analyzer

Cited by 19 publications

References 29 publications

Extraction of Mangiferin and Chemical Characterization and Sensorial Analysis of Teas from Mangifera indica L. Leaves of the Ubá Variety

Extraction of Mangiferin and Chemical Characterization and Sensorial Analysis of Teas from Mangifera indica L. Leaves of the Ubá Variety

A digital image-based micro-flow-batch analyzer

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