喷施稀土对茶叶中不同状态的稀土元素组成及含量的影响

Effects of Spraying Rare Earth on Compositions and Contents of Rare Earth Elements in Tea

:茶树叶面喷施稀土是一项增产提质的栽培措施。但人们关心外源稀土对茶叶中稀土元素(REE)含量、组成及存在状态所产生的影响。试验表明,喷施至采摘间隔期愈长,喷施稀土对茶叶中稀土含量及组成等的影响愈小。茶叶中REE约有80%左右以水不溶态残存于茶渣中,不进入茶汤。进入茶汤中的REE约有10%是以稀土多糖状态存在,其中尤以La、Ce、Nd为主。间隔期愈短,稀土进入茶汤的量及参与稀土多糖配合物的量愈高。

Tea plants sprayed rare earth can increase tea yield and quality,but the effects of spraying rare earth on the contents and compositions of rare earth elements(REE) in tea are unknown.The contents and compositions of REE in teas from tea garden sprayed 'Cheng Lu' rare earth,cont.300mg/kg and 750kg/ha,and from natural tea garden have been determined.The results show that the longer the interval between spraying and picking was,the less the effects of sprayed rare earth on contents and compositions of REE in the teas were.About 80% ΣREE in tea whether it came from spraying or no spraying the rare earth were insoluble in its infusion.There were about 10% the soluble REE in infusion,in particular La,Ce and Nd,participating in coordinating polysaccharide,the amount of REE which participated in forming polysaccharide 15 days after spraying the rare earth was larger than those of 25 days and 35 days.