不同预处理方式对复水薇菜尖单宁含量的影响

Effect of Different Pretreatments on the Tannin Content of Reconstituted Osmunda japonica Thunb Tip

考察pH值、包埋剂、金属离子在不同温度条件下对复水薇菜尖单宁含量的影响。结果表明：当pH8-9时，复水薇菜尖单宁脱除效果较好，单宁脱除率最高可达88．97％。DH值一定时，温度升高有利于单宁脱除。包埋剂卢一环状糊精、麦芽糊精和可溶性淀粉对复水薇菜尖单宁脱除均具有较好的效果，单宁脱除率均能达到80．76％以上。随着包埋剂用量增大，单宁含量呈先下降后上升的趋势；用量一定时，随着温度升高，单宁含量下降。金属离子钠离子、钾离子、钙离子和镁离子对复水薇菜尖单宁的脱除效果有所差异，其中钙离子的效果最优，单宁脱除率可达到88．04％；随着金属离子质量浓度增大，单宁含量先减小后增大。

The effects of pH, embedding medium and metal ion on the tannin content of reconstituted Osmundajaponica Thunb tip under different temperatures were studied. The experimental results indicated that the removal efficiency of tannin from reconstituted Osmundajaponica Thunb tip was good and reached a maximum level of 88.97% at pH 8-9. Increasing the temperature favored the removal of tannin at the same pH values. One of three embedding media, β-cyclodextrins, maltodextrin and soluble starch, was effective for removing tannin from reconstituted Osmunda japonica Thunb tip providing a removal efficiency of over 80.76%. Along with increasing the embedding medium concentration, the content of tannin rose at first and went down later. As the temperature increased, the content of tannin decreased at a constant concentration of embedding medium. The tannin removal effects of different metal ions （sodium ion, potassium ion, calcium ion and magnesium ion） on reconstituted Osmundajaponica Thunb tip were different and among them the most effective was calcium ion providing a removal efficiency of 88.04%. With increasing metal ion concentration, the content of tannin decreased firstly and increased subsequently. An increase in the temperature promoted tannin removal at a fixed concentration of metal ion.