噴施稀土對(duì)茶葉中不同狀態(tài)的稀土元素組成及含量的影響
汪東風(fēng) 曹心德 趙貴文 葉盛摘 要:tea .com/'>茶樹(shù)葉面噴施稀土是一項(xiàng)增產(chǎn)提質(zhì)的栽培措施。但人們關(guān)心外源稀土對(duì)tea .com/'>茶葉中稀土元素(REE)含量、組成及存在狀態(tài)所產(chǎn)生的影響。試驗(yàn)表明,噴施至tea .com/look.php?sid=4198'>采摘 間隔期愈長(zhǎng),噴施稀土對(duì)tea .com/'>茶葉中稀土含量及組成等的影響愈小。tea .com/'>茶葉中REE約有80%左右以水不溶態(tài)殘存于tea .com/'>茶渣中,不進(jìn)入tea .com/'>茶湯。進(jìn)入tea .com/'>茶湯中的REE約有10%是以稀土多糖狀態(tài)存在,其中尤以La、Ce、Nd為主。間隔期愈短,稀土進(jìn)入tea .com/'>茶湯的量及參與稀土多糖配合物的量愈高。關(guān)鍵詞:稀土元素;tea .com/'>茶葉;噴施;組成及含量分類號(hào):S131+.1
文獻(xiàn)標(biāo)識(shí)碼:A文章編號(hào):1004-0277(2000)01-0044-05 Effects of Spraying Rare Earth on Compositions and Contents ofRare Earth Elements in Tea WANG Dong-feng CAO Xin-de ZHAO Gui-wen(Department of Chemistry,University of Science and Technology of China,Hefei 230026)WANG Dong-feng YE Sheng(Key Laboratory of Tea Biotechnology,Anhui Agricultural University,Hefei 230036) Abstract: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 tea s 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 tea s 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.Key words:rare earth elements;tea ;spray;composition and content.▲
tea .com/'>茶葉是我國(guó)傳統(tǒng)的出口商品,內(nèi)銷也隨人們生活水平的提高而日益增多。為滿足市場(chǎng)需要,廣大tea .com/'>茶葉工作者不斷探討增產(chǎn)提質(zhì)新技術(shù)。葉面噴施稀土具有增產(chǎn)提質(zhì)、提早發(fā)芽、改善tea .com/'>茶鮮葉機(jī)械組成等作用〔1〕。但tea .com/'>茶樹(shù)噴施稀土后,新生幼嫩芽葉中稀土含量明顯上升〔2〕,這些幼嫩芽葉正是tea .com/'>茶葉加工的原料,tea .com/'>茶葉又是直接沖泡飲用。最近的研究結(jié)果表明〔3〕,人日攝入稀土僅為4.2mg。因此,稀土在tea .com/'>茶葉生產(chǎn)中應(yīng)用時(shí),人們十分關(guān)注噴施稀土對(duì)tea .com/'>茶葉中稀土存在狀態(tài)、在tea .com/'>茶湯中浸出率等的影響及tea .com/look.php?sid=4198'>采摘 間隔期問(wèn)題。目前雖有tea .com/'>茶葉中稀土總量〔2,4〕、礦區(qū)tea .com/'>茶葉REE組成〔5〕以及發(fā)現(xiàn)tea .com/'>茶葉中存在有稀土tea .com/'>茶多糖〔6〕等報(bào)道,但