The effect of ascorbic acid, citric acid and low pH on the extraction of green tea: How to get most out of it

Zimmermann, Benno F.; Gleichenhagen, Maike

doi:10.1016/j.foodchem.2010.08.009

Cited by 42 publications

(14 citation statements)

References 32 publications

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“…These results disagree with the findings in previous studies, which showed that acid pH (below 5) extracted the highest amounts of phenolic antioxidants in green tea (Zimmermann & Gleichenhagen, 2011). Nevertheless, in other study developed by Pérez-Martínez et al (2010), an increase in the antioxidant capacity of coffee brew was found when there was a limited increase in the pH (5.2 to 5.4) due to the addition of pHregulator agents to extent coffee brew self-life.…”

Section: Influence Of Water Phcontrasting

confidence: 99%

Influence of extraction process on antioxidant capacity of spent coffee

Bravo

Monente

Juániz

et al. 2013

Food Research International

132

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Spent coffee that is produced in tons by restaurants and cafeterias, and consumers at domestic levels, could be a good opportunity to have an important source of natural antioxidants. The main aim of this work was to study the influence of several process factors on the antioxidant capacity extraction from spent coffee. Total phenolic compounds, radical scavenging activity (ABTS and DPPH) and browned compounds (Abs 420nm) of spent coffee extracts obtained with continuous (soxhlet 1h and 3h) and discontinuous methods (solid-liquid extraction and filter coffeemaker), several solvents (water, ethanol, methanol and their mixtures), successive extractions, and water with different pHs (4.5, 7.0 and 9.5) were carried out. Spent coffee extracts with the highest antioxidant capacity were obtained after one extraction with neutral water (pH 7.0) in a filter coffeemaker (24 g spent coffee per 400mL water). Furthermore, spent coffee defatting and extracts lyophilization allowed us to obtain spent coffee extracts powder with high antioxidant capacity that can be used as an ingredient or additive in food industry with potential preservation and functional properties.

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Section: Influence Of Water Phcontrasting

confidence: 99%

Influence of extraction process on antioxidant capacity of spent coffee

Bravo

Monente

Juániz

et al. 2013

Food Research International

132

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“…Extraction of these phenolics was also diminished with lowering of temperature. Usually for the highest catechin content, water extraction procedure of tea is made in 3-5 min at 100°C (Komes et al 2010;Rusak et al 2008;Unachukwu et al 2010;Wu et al 2012;Zimmermann and Gleichenhagen 2011). Our results show that for the other compounds such as rutin and chlorogenic acid, extraction time extended to 15 min is better.…”

Section: Optimization Of Extraction Process By Rsmmentioning

confidence: 75%

“…This common beverage is a great source of phenolic compounds such as flavonoids and phenolic acids which are responsible for the total antioxidant activity of tea infusion (Kim et al 2011). Catechins or flavan-3-ols are the dominant phenolics in green tea leaves and its infusion, but they are frequently determined (Friedman et al 2005;Horzic et al 2009;Poon 1998;Rusak et al 2008;Zimmermann and Gleichenhagen 2011). Other compounds aside from catechins or flavan-3-ols are rarely analyzed in tea, and therefore, it is interesting to determine these compounds in different types of tea available on the market.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Antioxidant Activity, Chlorogenic Acid, and Rutin Content of Camellia sinensis Infusions Using Response Surface Methodology Optimization

Jeszka-Skowron

Zgoła‐Grześkowiak

2014

Food Anal. Methods

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Optimization of the extraction process of green tea using response surface methodology (RSM) was performed. The optimized conditions were 14.91 min and 94.15°C (2,2-diphenyl-1-picrylhydrazyl (DPPH) assay). The experimental values were close with the predicted values. The procedure was used to measure antioxidant activity using DPPH free radical and phenolic compounds of all types of Camellia sinensis and Tabebuia impetiginosa infusions. The antioxidant activity of infusions was in the order (mean for analyzed types) of pure green tea > white tea > green tea with additives > black tea = Pu-erh tea > semifermented tea > Red Lapacho. After the fermentation process, the content of rutin is lowered and the amount of gallic acid in infusions is increased. A negative correlation between total phenolic acids and organic acids was also observed (R 2 =0.6437). Red Lapacho infusion contains phenolic acids such as caffeic, protocatechuic, pcoumaric, ferulic, and syringic. No rutin and quercetin were found in this beverage.

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“…Based on our experience with polyphenol analysis [15][16][17][18][19][20] and mass spectrometric structure elucidation [21], we have developed a rapid analytical method to characterize and quantify the major polyphenolic sage constituents including hydroxycinnamic acids and their derivates (e.g., caffeic acid or rosmarinic acid), flavon glycosides and phenolic terpenes (e.g., carnosic acid). With this, we will be the first to provide a comprehensive overview of 16 different sage tea brands from the German market.…”

Section: Introductionmentioning

confidence: 99%