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Flavonoids, total phenolics and antioxidant capacity: comparison between commercial green tea preparations
The potential health benefits attributed to green tea and its catechins such as antioxidant effects, cancer chemoprevention, and weight loss have led to a huge increase of green tea products in the food market. The objectives of this work were to analyze and compare these products in terms of phenol...
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Published in: | Ciência e tecnologia de alimentos 2010-12, Vol.30 (4), p.1077-1082 |
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Main Authors: | , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that cite this one |
Online Access: | Get full text |
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Summary: | The potential health benefits attributed to green tea and its catechins such as antioxidant effects, cancer chemoprevention, and weight loss have led to a huge increase of green tea products in the food market. The objectives of this work were to analyze and compare these products in terms of phenolic contents and in vitro antioxidant capacity including tea bags, dehydrated leaves, and ready-to-drink preparations after standardization of the infusion preparation procedure. Total phenolics content in 1 cup of the different teas varied from 90 to 341 mg of catechin equivalents, and the highest and the lowest values were both those of the ready-to-drink products. Infusions prepared from tea bags had contents varying from 96 to 201 mg.200 mL-1, and there were no significant differences among batches. The DPPH radical scavenging and the Oxygen Radical Absorbing Capacities (ORAC) varied largely among the different tea preparations, from 23 to 131 mmoles of Trolox Equivalents (TE).200 mL-1 (DPPH), and from 1.2 to 5.1 mmoles of TE.200 mL-1 (ORAC), but again there were no differences among infusions or ready-to-drink commercial preparations. However, the antioxidant capacity of ready-to-drink products was partially due to the presence of other non-phenolic compounds such as ascorbic acid
Os benefícios de saúde atribuídos ao chá verde e suas catequinas têm levado a um grande aumento de produtos comerciais à base de chá verde no mercado. Os objetivos deste trabalho foram analisar e comparar estes produtos em relação ao conteúdo de fenólicos totais e capacidade antioxidante in vitro, incluindo produtos na forma de sachês, folhas desidratadas e bebidas prontas. O conteúdo de fenólicos totais em 200 mL (1 xícara) dos diferentes chás variou de 90 a 341 mg equivalentes de catequina, e o maior e o menor valor foram apresentados pelas bebidas prontas. As infusões preparadas a partir dos sachês tiveram conteúdos variando de 96 a 201 mg.200 mL-1, e não foram encontradas diferenças significativas entre os lotes. Nos ensaios de sequestro do radical DPPH e ORAC (Oxygen Radical Absorbing Capacity), houve ampla variação dos resultados entre as diferentes preparações de chás, de 23 a 131 mmoles equivalentes de Trolox (ET).200 mL-1 (DPPH), e de 1,2 a 5,1 mmoles ET.200 mL-1 (ORAC), e novamente não houve diferenças entre as infusões e/ou bebidas comerciais prontas. Entretanto, a capacidade antioxidante das bebidas prontas para consumo é parcialmente devido à presença de outros compost |
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ISSN: | 0101-2061 1678-457X 1678-457X |
DOI: | 10.1590/S0101-20612010000400037 |