Determination of caffeine content in tea beverages

Abstract

Caffeine is the main component and characteristic indicator of tea beverages, and it is also a stimulant of the central nervous system. In this paper, the content of caffeine in 19 tea beverage samples in the market were determined by the ultraviolet spectrophotometry method, which was convenient, rapid, effective and low cost. The results showed that caffeine was detected in all samples as an inherent component of tea itself. The content of caffeine in green tea beverages, milk-flavored tea beverages and scented tea beverages was higher than that of black tea beverages and oolong tea beverages due to the different types of raw tea. Because of the difference in the source of raw tea and the difference in production process and formula, the caffeine content of beverages from different manufacturers of the same tea varieties was also significantly different, and there was great difference both in green tea beverages and in black tea beverages. The caffeine content in all samples met the requirements of Chinese national standard and did not exceed the prescribed limits set by the United States, Canada, Japan and other countries.