Effect of Ca~(2+) on the Chemical Components and Sensory Quality of Extracted Green Tea Infusion

The effect of different Ca2+ concentration(0～100 mg/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.