The fortification of tea with sweeteners and milk and its effect on in vitro antioxidant potential of tea product and glutathione levels in an animal model

Korir, M. W.; Wachira, Francis N.; Wanyoko, J. K.; Ngure, R. M.; Khalid, Rozida Mohd.

doi:10.1016/j.foodchem.2013.08.016

Cited by 53 publications

(37 citation statements)

References 41 publications

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“…Hence, it is supposed that those antioxidant activities may be due to high level of total phenolic compounds and flavonoids (r = 0.245 and 0.310, respectively). These results are in agreement with the results obtained by Hwang et al (2010), Afify et al (2011), Korir et al (2014) and Turumtay et al (2014) who mentioned that antioxidant activity of green tea was higher than black tea and these were positively correlated with phenolic and flavonoids content.…”

Section: Dpph Radicalsupporting

confidence: 93%

Suggested mechanism for the effect of sweeteners on radical scavenging activity of phenolic compounds in black and green tea

Shalaby

Mahmoud

Shanab

2016

Frontiers in Life Science

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The present work aims to evaluate the relation between the antioxidant activities and phenolic compound contents of two tea samples (green and black) mixed with or without sweeteners (sucrose or aspartame). The aqueous extracts were screened for total polyphenol and flavonoids contents. Antioxidant activities of extracts were tested using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical method and 2, 2 -azino-bis [ethylbenzthiazoline-6-sulfonic acid] (ABTS) methods using butylated hydroxyl anisole as standard compound. In addition, we identified polyphenols compounds using high performance liquid chromatography (HPLC). The results indicated that the antioxidant activity was higher against ABTS radical more than DPPH radical. Also, there is positive correlation between the antioxidant activity and phenolic compounds content presented in water extracts of tea samples. The results also indicated that addition of table sugar to green tea significantly decreased the antioxidant activity (from 95.8% to 90.6% with 4.0% sucrose). However, the same table sugar in black tea increased the antioxidant activity (from 87.0% to 91.9% with 4.0% sucrose). The analysis using HPLC showed that caffeine was the most predominant individual compounds in green and black tea without and with 1.0% sucrose (6081.8, 8772.1, 6474 and 3755 µg/100g, respectively). However, cinnamic acid showed the lowest content in the same tea samples (0.21, 0.25, 0.19 and 0.18 µg/100g respectively). Pyrogallol, catechol, epicatechin, ellagic, protocatchuic were significantly higher in green tea than in black tea. ARTICLE HISTORY

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Section: Dpph Radicalsupporting

confidence: 93%

Suggested mechanism for the effect of sweeteners on radical scavenging activity of phenolic compounds in black and green tea

Shalaby

Mahmoud

Shanab

2016

Frontiers in Life Science

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“…When considering the effect of biosorption within the same sample, only GT showed a decrease (statistically significant) with TEAC assay (Table 1). Many investigations confirmed that the lowering of tea antioxidant capacity may be ascribed to the interactions with proteins (Dubeau et al, 2010;Korir, Wachira, Wanyoko, Ngure, & Khalid, 2014;Ye et al, 2013). Despite the data obtained in this study revealing that the tea infusions after biosorption generally had lower TPC and consequently lower TAC than had in the initial samples, these green and black tea infusions still retained high radical scavenging activities.…”

Section: Phenolic Content and Antioxidant Capacities As Affected By Bcontrasting

confidence: 51%

Biosorption of green and black tea polyphenols into Saccharomyces cerevisiae improves their bioaccessibility

Jilani

Cilla

Barberá

et al. 2015

Journal of Functional Foods

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“…Most notably, the EGCG content in GT and orthodox BT was almost 50-fold higher than in CTC black tea [268]. Numerous studies have also shown that that the addition of milk to BT, which is the common practice in Western countries, has been found to further reduce the antioxidant potential of BT [269–272]. An unexpected finding is that the addition of milk to GT has been found to enhance the antioxidant capacity of GTs [273, 274].…”

Section: Discussionmentioning

confidence: 99%

Black Tea Source, Production, and Consumption: Assessment of Health Risks of Fluoride Intake in New Zealand

Waugh¹,

Godfrey

Limeback

et al. 2017

Journal of Environmental and Public Health

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In countries with fluoridation of public water, it is imperative to determine other dietary sources of fluoride intake to reduce the public health risk of chronic exposure. New Zealand has one of the highest per capita consumption rates of black tea internationally and is one of the few countries to artificially fluoridate public water; yet no information is available to consumers on the fluoride levels in tea products. In this study, we determined the contribution of black tea as a source of dietary fluoride intake by measuring the fluoride content in 18 brands of commercially available products in New Zealand. Fluoride concentrations were measured by potentiometric method with a fluoride ion-selective electrode and the contribution of black tea to Adequate Intake (AI) and Tolerable Upper Intake Level (UL) was calculated for a range of consumption scenarios. We examined factors that influence the fluoride content in manufactured tea and tea infusions, as well as temporal changes in fluoride exposure from black tea. We review the international evidence regarding chronic fluoride intake and its association with chronic pain, arthritic disease, and musculoskeletal disorders and provide insights into possible association between fluoride intake and the high prevalence of these disorders in New Zealand.

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The fortification of tea with sweeteners and milk and its effect on in vitro antioxidant potential of tea product and glutathione levels in an animal model

Cited by 53 publications

References 41 publications

Suggested mechanism for the effect of sweeteners on radical scavenging activity of phenolic compounds in black and green tea

Suggested mechanism for the effect of sweeteners on radical scavenging activity of phenolic compounds in black and green tea

Biosorption of green and black tea polyphenols into Saccharomyces cerevisiae improves their bioaccessibility

Black Tea Source, Production, and Consumption: Assessment of Health Risks of Fluoride Intake in New Zealand

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