DETERMINATION OF CAFFEINE CONTENTS OF COFFEE BRANDS IN THE VIETNAMESE MARKET

摘要

In this study, the caffeine contents in five certain Vietnamese coffee (Dak Tin, Di Linh, Nam Nguyen, Origin and Vinacafe) found in the Vietnamese market were determined using UV/vis spectrophotometry. The quantification of caffeine sample was calculated by standard addition method. Our results showed that the caffeine contents in coffee brewing were influenced by temperature of water used to brew, time of brewing, and independent on the volume of water, respectively. In general, higher concentrations of caffeine were found in all samples prepared at temperature 100°C for 5 minutes. The order of caffeine contents in coffee samples was Dak Tin, Di Linh, Nam Nguyen, Origin and Vinacafe, respectively. This study can contribute to a better knowledge of caffeine contents in Vietnamese coffee of Vietnamese consumers.