The content of bioactive constituents as a quality index for Vietnamese teas

Although Vietnam is one of the largest tea producing countries in the world, there is only limited data on the quality of Vietnamese grown teas. To provide a general measure of quality for Vietnamese grown teas, the content of catechins and caffeine in Vietnamese green, black and oolong teas was determined and compared with teas from other countries. The results showed that the content of catechins and caffeine in Vietnamese grown green teas was 70 mg/g and 21 mg/g whereas the levels were 34 mg/g and 19 mg/g in Vietnamese oolong teas and 12 mg/g and 20 mg/g in Vietnamese black teas, respectively. The findings also indicated that, despite some minor differences, the three types of Vietnamese teas were found to be comparable to their Chinese, Japanese and Australian marketplace counterparts.