Total Polyphenol Content and Antioxidant Capacity of Tea Bags: Comparison of Black, Green, Red Rooibos, Chamomile and Peppermint over Different Steep Times

Riley Cleverdon,William Gittings,Yasmeen Elhalaby,Michael Mcalpine,Wendy Ward

doi:10.3390/beverages4010015

Abstract

Globally, traditional and herbal teas are a prominent dietary source of polyphenols, and represent a class of bioactive molecules that are closely associated with a variety of health benefits. Most consumers prepare tea using tea bags, although there is little information about whether this production step alters the content of the final product. The study purpose was to investigate the effect of steep time and tea type on the polyphenol content and predicted antioxidant capacity of commercially available tea bag products, including Green, Orange Pekoe, Red Roiboos, Peppermint, and Chamomile. Total polyphenol content (TPC), antioxidant capacity (1,1-diphenyl-2-picrylhydrazyl inhibition), and total predicted antioxidant capacity were measured in aliquots sampled every minute for 10 min. Polyphenols were extracted into solution in a nonlinear fashion, with ~80–90% of the TPC appearing within 5 min of tea bag immersion. Moreover, a significant range in TPC values was observed between products, with true teas containing at least two-fold greater polyphenol content than the herbal varieties. Our results are consistent with previous work using loose-leaf tea products and demonstrates that tea bag products are an effective source of polyphenols that may offer health benefits relating to their constituent antioxidant activity.

Highlights

Tea, green and black, is increasingly being studied for its potential role in the prevention and attenuation of a wide variety of diseases [1,2,3,4,5,6]
Given that the term tea is often used erroneously to refer to rooibos and herbal beverages that do not originate from Camellia sinensis, it is important to acknowledge that these beverages are most accurately referred to as tisanes while recognizing that both tea and tisanes all have polyphenols, a common component that is believed to mediate health benefits
We have investigated the extraction and potential health-promoting qualities of polyphenols sampled from a variety of tea products as they would be consumed habitually by millions of individuals across the globe every day

Summary

Introduction

Green and black, is increasingly being studied for its potential role in the prevention and attenuation of a wide variety of diseases [1,2,3,4,5,6]. There is a strong interest in rooibos as it does not contain caffeine and many herbal tisanes are caffeine-free, whereas a single cup of green or black tea from the Camellia sinensis plant contains approximately 30–50 mg of caffeine per serving while a serving of brewed coffee contains 135 mg [12]. To put this in perspective, Health Canada’s recommendations suggest no adverse effects in adults with caffeine intakes of up to 400 mg [12]

Objectives

Methods

Results

Discussion

Conclusion