ChemInform Abstract: Catechins of Green Tea: Antioxidant Activity

Lunder, T. L.

doi:10.1002/chin.199346335

Cited by 7 publications

(10 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(1983) pointed out that EC exhibited better antioxidant activity than other catechins. Lunder (1992) found that the EGCG content of tea leaves correlated well with its antioxidant activity. Chen and Ho (1995) studied antioxidant activities by the Rancimat method and the effectiveness in the inhibition of lipid peroxidation was in the descending order: EGCG > ECG > EGC > EC.…”

Section: Resultsmentioning

confidence: 99%

Antioxidant Properties of Water Extracts From Parching Green Tea

Lin

Liang

Liu

et al. 2010

Journal of Food Biochemistry

View full text Add to dashboard Cite

Cold and hot water extracts (2, 6 and 10%) were prepared from parching green tea and its antioxidant properties studied and potential antioxidant components determined. Yields of hot water extracts (17.53-28.63%) were significantly higher than those of cold water extracts (13.34-16.14%). The half maximal effective concentration (EC(50)) values in antioxidant activity and reducing power were 2.17-2.75 and 0.22-0.30 mg/mL, respectively. Scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl radicals were comparable. EC(50) values in scavenging ability on hydroxyl radicals and chelating ability on ferrous ions were 3.31-4.54 and 1.63-3.09 mg/mL, respectively. Contents of total phenols were 220.52-339.83 mg/g whereas those of total catechins in cold and hot water extracts were 130.22-146.28 mg/g and 136.40-191.33 mg/g, respectively. Based on the results obtained, hot water extracts were more effective in antioxidant activity, reducing power and scavenging ability on hydroxyl radicals but less effective in chelating ability on ferrous ions. PRACTICAL APPLICATIONS Tea is one of popular drinks in the world. The consumption of green tea is especially popular in Asia, mainly for its health benefits. Parched tea is a Chinese style green tea, which is different from the Japanese style steamed tea. Recently, the tea prepared by brewing tea leaves in cold water has become a new choice in Taiwan in addition to traditionally hot water-brewed tea. Results from this research, the cold and hot water extracts of green tea are good antioxidant. Besides, green tea is also reported to reduce serum cholesterol levels and inhibit hypertension, mutagenesis, and tumourigenesis in several experiments in vitro and in vivo. Therefore, the extract of green tea has the potential to be developed into new health foods, and the cold brewing would be a new alternative way to make a tea

show abstract

Section: Resultsmentioning

confidence: 99%

Antioxidant Properties of Water Extracts From Parching Green Tea

Lin

Liang

Liu

et al. 2010

Journal of Food Biochemistry

View full text Add to dashboard Cite

show abstract

“…Green tea ( Camellia sinensis ), one of the most common beverages in the world, is usually brewed in cold or hot water. The beverage has been claimed to have an array of health benefits including anticancer and antioxidant abilities [1] [2] . The agents responsible for health improvement from tea are known as catechins.…”

Section: Introductionmentioning

confidence: 99%

“…There are four major types of catechins in tea, epigallocatechin-3-gallate (EGCG), gallocatechin gallate (GCG) epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC), with EGCG being the most abundant among all catechin types [3] . As EGCG contains eight hydroxyl (OH - ) groups, it can remove multiple free radicals which allows it to become one of the more potent antioxidants [3] [2] , additional researches show that the chemical has anti-cancer [1] , anti-inflammatory effects and can improve learning and memory retention skills [4] .…”

Section: Introductionmentioning

confidence: 99%

Epigallocatechin-3-gallate yield in different temperature gradients in green tea (Camellia sinensis) brewing

Hsieh¹,

Hsieh

et al. 2018

Preprint

View full text Add to dashboard Cite

IntroductionEpigallocatechin-3-gallate (EGCG) is a chemical catechin, a natural organic compound found in green teas with strong antioxidative effects. EGCG degrades or epimerizes according to temperature, fluctuating its concentration in green tea (Camellia sinensis). This study is conducted to determine the specified correlation between EGCG and tea temperature, and to conclude with the optimal temperature for EGCG yield.MethodsEGCG concentrations in different solutions of green tea are analyzed using a high-performance liquid chromatography (HPLC), with a diode array detector (DAD). The solutions are created from green tea brewed in water from 20°C to 100°C at increments of 20°C and undergo an ultrasonic bath of 30 minutes before being analyzed.ResultsThere is a discernible difference between EGCG concentrations in all temperatures. At 20, 40, 60, 80 and 100°C, the concentrations are 6.18 μg/mL, 32.37 μg/mL, 57.36 μg/mL, 36.13 μg/mL, and 44.85 μg/mL, respectively. EGCG concentration maximizes at 60°C. The lowest EGCG concentration yield is at 20°C.ConclusionThe results of our experiments lead us to recommend hot brewing over cold brewing for green tea if one wishes to maximize the potential of the effects of EGCG due to its higher concentration.

show abstract

“…The composition of black tea leaf is shown in Table 1. The literature reports a wide range of polyphenol compositions, from 8–40% (Balentine 1992; Lunder 1992; Astill et al. 2001).…”

Section: Introductionmentioning

confidence: 99%

“…The composition of black tea leaf is shown in Table 1. The literature reports a wide range of polyphenol compositions, from 8-40% (Balentine 1992;Lunder 1992;Astill et al 2001). The polyphenols present in black tea are mainly TRs, TFs, bisflavanols, and catechins (Todisco et al 2002).…”

Section: Introductionmentioning

confidence: 99%

The Interaction of Protein and Polyphenol Species in Ready to Drink Black Tea Liquor Production

Bird²

2010

J Food Process Engineering

View full text Add to dashboard Cite

Haze and tea cream generation is a serious problem in the production of ready‐to‐drink (RTD) black tea liquors. Such precipitates consist primarily of proteins and polyphenols. Tea protein and tea polyphenol have been separated successfully in this study. The interactions of (1) tea protein and mixed TF; and (2) tea protein and total tea polyphenol were studied by ITC. A series of techniques, including gel filtration chromatography, sodium dodecyl sulfate polyacrylamide gel electrophoresis, CBB assay and fourier transform infrared spectroscopy (FTIR), have been used to determine the quantity and properties of proteins isolated from black tea powder. The molecular mass of the tea protein was detected to be approximately 11 kD at pH 5.0. The purity of this protein isolate was 51.4 wt % and a possible β‐sheet secondary structure was indicated from FTIR spectra. The total phenols in the tea polyphenol sample separated by Zn 2+ precipitation under alkali conditions (pH 7.5) was increased to approximately 65 wt % of the sample tested. The binding mechanism of tea protein and TF was somewhat different from that of tea protein and total tea polyphenol, although both interactions were successfully fitted using a sequential sites binding model. PRACTICAL APPLICATIONS In black tea liquor production, polyphenols tend to interact with proteins, caffeine and metal cations to form colloidal suspensions of haze and “tea cream”, which are detrimental to product appearance and taste. This is a key concern in the production of ready‐to‐drink (RTD; iced tea) beverages, which are typically made from reconstituted spray dried tea powders and stored at low temperatures (potentially leading to precipitation). Tea cream and haze are traditionally removed by dissolution through pH adjustment. The size of haze and tea cream aggregates means that membrane technology can offer an alternative nonchemical separation option. To facilitate the removal of haze and tea cream in commercial RTD tea production, it is important to increase the level of understanding of polyphenol or tea protein interactions that occur in black tea liquor. Such interactions are the focus of this paper.

show abstract

ChemInform Abstract: Catechins of Green Tea: Antioxidant Activity

Cited by 7 publications

References 1 publication

Antioxidant Properties of Water Extracts From Parching Green Tea

Antioxidant Properties of Water Extracts From Parching Green Tea

Epigallocatechin-3-gallate yield in different temperature gradients in green tea (Camellia sinensis) brewing

The Interaction of Protein and Polyphenol Species in Ready to Drink Black Tea Liquor Production

Contact Info

Product

Resources

About