Abstract: The effect of different Ca²⁺ concentration（0~100mg/L）on the chemical components and sensory quality of extracted green tea infusion was investigated. The results showed that, with the increasing of Ca²⁺ concentration, the turbidity of tea infusion increased, pH decreased; the contents of total solids and free amino acids increased, the contents of tea polyphenols and protein decreased, but there was no significant difference in the contents of caffeine and flavones; the contents of EGC increased, the contents of C, EGCG, GCG, ECG and CG decreased, but there was no significant difference in the contents of EC; the contents of Al³⁺, Cu²⁺, Na⁺, Zn²⁺ decreased, and the contents of K⁺, Mg²⁺, Mn²⁺ increased; tea infusion turned turbid, ripe and sulks odour enhanced, and bitter and astringency strengthened. The effect of Ca²⁺ on tea infusion quality maybe arisen by participating in tea cream formation, inducing epimerisation of catechins and appearing decomposition reaction.

Key words: Ca²⁺, green tea infusion, chemical components, sensory quality