JAVIER GARCÍA-LOMILLO¹*, M LUISA GONZÁLEZ-SANJOSɹ
*Corresponding author
1. Department of Biotechnology and Food Science, Faculty of Sciences,
University of Burgos, Plaza de Misael Bañuelos, 09001 Burgos, Spain.

Abstract

Decaffeinated beverages are rising in popularity among coffee and tea drinkers; however, little is known about the effect of the decaffeination process on the total antioxidant capacity (TAC). The aim of this work was to determine whether there is a significant difference between regular beverages and their decaffeinated equivalents in terms of the TAC. Colour, total phenolic content, total catechin content, and antioxidant activities (ABTS+, FRAP, DPPH) were determined in five commercial black teas and six commercial instant coffees as well as their respective decaffeinated products from the same brand. Only one of the brands showed significant differences in all the tests and no clear differences were reported. In the factorial analysis, it was observed that samples were associated according to their brands rather than according to their caffeine content. Consequently, factors associated with the brand are in fact, what determine the TAC of the beverage.

INTRODUCTION 

Coffee and tea are two of the most consumed drinks in the United Kingdom. According to the last European coffee report, 3 kg of coffee were consumed per person in 2011; which means that more than 60 million cups of coffee are consumed per day in the UK. Because it is easier to make, instant coffee is consumed more than any other type of coffee (75% of coffee is drunk as instant coffee). As far as tea is concerned, the United Kingdom has the second highest tea consumption rate in the world (2.1 kg of tea per person). More than 165 million cups of tea are drunk per day, according to the estimations of the UK Tea Council (1).
The demand for decaffeinated coffee and tea is increasing and their intake represents around 15% of the coffee and tea market. Consumers are aware of caffeine effects on health which could explain the increase in the demand for decaffeinated products. It is well known that sleep is affected by consumption of caffeine. Moreover, nervousness, agitation, and anxiety are caused by consumption of non-decaffeinated coffee and tea (2). In addition to that, caffeine has been directly associated with several types of canc ...