Abstract: The quality components including amino acids, polyphenols, caffeine, soluble sacchrides and main nutrient elements in tea were measured under ambient and elevated CO₂ conditions, and effects of elevated atmospheric CO₂ concentration on tea quality were analysed. The results showed that amino acid contents in tea decreased by 1.7%~4.5% and 6.7%~12.2% under elevated (500 and 750βμmol/mol) CO₂, compared to the ambient air CO₂ concentration. At the same time, the caffeine contents reduced by 3.1%~4.6% and 5.1%~10.7%. The polyphenol contents increased by 3.8%~6.0% and 6.9%~11.3%. The solule sacchride contents increased by 8.4%~14.4% and 18.1%~28.2%. It was also found that the N, K, Ca, P and Na contents in tea decreased to some extent. The Zn, Mg and Fe contents increased with CO₂ enrichment.

Key words: CO₂, elevated, quality, tea