A Study On Extraction Techniques For White Tea Beverage

White Peony produced in Zhenghe,Fujian province was used as test materialsfor the studies on the rate of chemicals dissolution in water and the sensory quality oftea infusions when conventional extraction and enzyme-assisted extraction methodswere applied to the materials. The results were as follows:In the conventional extraction process, the rate of chemicals dissolution inwater,(1) increased greatly with the increasing ratio of water to dry tea leaf untill theratio of water to dry tea leaf reached70:1;(2) could be greatly promoted with risinginfusing temperature untill the infusing temperature reached60℃~70℃;(3) sloweddown after infusing of45min. As far as the dissolution rate and the sensory quality oftea infusion were concerned, white tea was better infused at ratio of dry tea leaf towater on the range of1:50~1:80, or at temperature on the range of40℃~70℃,or for15min~45min. The highest rates of the chemicals dissolution were achieved for waterextracts (36.17%)and soluble sugar (3.18%), polyphenol (18.03%), amino acid(2.82%) when infused at1:80of dry tea leaf to water at70℃for45min, at1:80of drytea leaf to water at70℃for15min and at1:70of dry tea leaf to water at70℃for45min respectively.In papain-assisted extraction process, white tea was better infused at ratio ofdry tea leaf to water on the range of1:50~1:80, or at temperature on the range of40℃~70℃,or at pH value of5.0~7.0, or for15min~45min when papain was added tothe infusion (papain content2%~8%). The highest rates of the chemicals dissolutionwere achieved for water extracts (42.06%) and amino acid (4.22%), polyphenol(22.17%) when infused at1:65of dry tea leaf to water at63℃for45min, with pHvalue5.0~7.0and papain content5%,and at1:80of dry tea leaf to water at70℃for45min, with pH value6.0and papain content2%respectively.In the cellulase-assisted extraction process, white tea was better infused atratio of dry tea leaf to water on the range of1:60~1:80, or at temperature on the rangeof40℃~70℃,or at pH value of4.5~6.5, or for15min~45min when cellulase wasadded to the infusion(cellulase content0.5mg/g~2mg/g). The highest rates of thechemicals dissolution were achieved for water extracts (58.07%),polyphenol(32.50%),amino acid (3.34%) when infused at1:80of dry tea leaf to water at55℃for 45min, with pH value5.5and cellulase content2mg/g,at1:80of dry tea leaf to waterat70℃for45min, with pH value6.5and cellulase content0.5mg/g,and at1:75of drytea leaf to water at55℃for30min, with pH value5.5and cellulase content2mg/grespectively.Comparisons were also made between the conventional extraction andenzyme-assisted extraction about infusion clarity changes during storage, the resultsindicated that the enzyme assisted extraction contributed to the stability of the teainfusion.