Preparation Of Wuyi Rock Tea Lactobacillus Fermented Beverage

In this study, Wuyi rock tea was selected as the object of reserch , active constituents in the tea were extracted by the ultrasonic method , Multifuntional lactice acid fermented tea beverage was prepared by proper lactic acid fermentation technolgy. The bevrage had the healthcare function of Wuyi rock tea and contained lactobacillus, not only had the oxidation resistence function of rock tea been preserved, but also had its healthcare function been increased , its flavor and taste was special , its commercial value was expected to be incresed .Gallocatechin gallate(GCG) and caffeine,two main active ingredients in Wuyi rock tea , their variation before and after fermentation had been studied. Their influence on the oxidation resistance activity: eliminate DPPH free radical(DPPH·), superoxide anion(O2-.) and chelation ferrous ion(FEC) had been investigated also. Main results were as follows:(1) Rock tea extraction was inoculated with Streptococcus thermophilus , fermented at the temperature of 37℃, the optimal fermentation time was 48h, viable counts were highest, which reached to 2.24×109 cfu/mL.(2) High Performance Liquid Chromatography analysis indicated that : when inoculation quantity was 6.8E+03 cfu/mL, the concentrations of GCG and caffeine reached to highest lever , which was 0.25mg/g and 16.76mg/g respectively , and both were lower than unfermented beverage (0.29mg/g and 18.23mg/g respectively) , the concentration of GCG had tendency of decrease with the increase in the quantity of inoculation lactobacillus , while the decrease in caffenin was not obvious .(3) Oxidation resistance activity analysis indicated that: during the concentration extent of 250~4000ppm, the ability of tea extraction to eliminate DPPH free radical superoxide anion and chelation ferrous ion was 93.78%,96.65% and 85.67% relatively. While after fermentation by lactobacillus , the Oxidation resistance activity decreased to 89.74%,87.71% and 85.67% relatively.(4) The research development of lactic acid fermented tea beverage of the main ratio for: 85% tea liquid, 8% milk powder, 5% lactic acid bacteria inoculation amount (6.8 E+03 cfu/mL), 2% other ingredients. After the examination, the main functional constituents in the beverage were: 82.04mg/g tea polyphenol, 115.54mg/g amino acid , 396.63mg/g tea polysaccharide, the product sensory evaluation was favorable.