Research On Green Tea Milk Power Form Longjin Green Tea

Green tea milk power, made form milk and green tea, which was nutritional and healthy, was to became research focus in recent decades. In this paper, the technology of processing green tea milk power from tea power and tea extract were developed. Some conclusion were made as follows;The optimal technology of extracting tea-polyphenols with ethanol was that: ethanol concentration was 50%, extracting time was 45 minutes for 4 times, extracting time was 70℃and the ratio ethanol to tea power was 20. The optimal technology of microwave-aid extract was that: pre-extract for 30 minutes, extract with low for 4 minutes twice, the ratio ethanol to tea power was 40, and ethanol concentration was 40%. The optimal technology of ultrasound-aid extract was that: extract temperature was 50℃, extracting time was 25 minutes twice, the ethanol/ tea ratio was 14, and ethanol concentration was 80%. The optimal technology of extracting caffeine by microwave was that: liquid/ solid ratio was 20, extract by microwave with low power for 3 minutes three times. the optimal extracting technology by ultrasound was that: the power of ultrasound was 100%, extracting time was 25 minutes twice, the liquid/solid ratio was 25, and ultrasound temperature was 80℃。his result shown that the extraction ratios by microwave-aid method and ultrasound-aid method were slightly higher than that of soxhlet extraction.Polysaccharide concentration in Longjin green tea was evenly 5.23%, so it was healthy. The concentration of total dietary fiber, soluble dietary fiber and insoluble dietary fiber was 14.84%, 2.14% and 12.70%, respectively. After that longjin tea was hydrolysis by celluase, the concentration of soluble fiber increase sharply and that of insoluble fiber decreased, and the total dietary fiber decreased slightly.It is both feasible to process green tea milk with power and extract form longjin green tea. Green tea components in green tea milk processing with tea extract was less than that of tea power, while the texture of green tea milk processing with tea extract was otherwise better than that of tea power, the color and flavor of the former were worse.The results could been taken as references to develop a new style product processed by tea and milk.