Research On The Influence Of Key Technology To Color And Turbidity Of Black Tea Beverage

Tea drinks were popular by consumers for its nutritional and healthy effects.Nowadays tea drinks was developing rapidly in China, however, most of tea drinks wereflavoring tea, pure tea drinks were rare in the market. Because pure tea drinks were easy tochange their color and form sediment, due to high concentration. By comparing the color,fragrance and optical density obtained under different extracting conditions, found theextracting pH, time, temperature concentration, water quality, and sterilization methodshad important influence on the preparation of black tea beverage. Taking the extraction rateof TR/TF and the sensory grading of black tea extracted fluid as the main evaluationindicators, and obtained the best extractive technique of black tea.By single factor design, this test studied on turbidity, chromatic values L*and SD,tea color and sensory evaluation analysis, the best extractive technique of black tea wasthat pH was5.5~6.5, temperature was80℃~90℃, time was5min~10min, ratio of tea andwater was1:40~1:80, the liquor carried no precipitation, a full color, a mellow taste and arich fragrance with it.Determine the single factor extraction conditions, taking into account the interactionbetween the single factors, and by orthogonal test. By analyzing the turbidity, color andsensory quality of green tea liquor processed with different raw tea. The best processingtechnology was considered with the analytic, the result showed that the best extractivetechnique of black tea was that pH was6.0, temperature was90℃, time was10min, ratioof tea and water was1:60.The hardness value, conductivity and turbidity of distilled electric water and purifiedwater was low, The tea beverages extracted and blended with distilled water and purifiedwater had the highest degree of brightness, however a lighter color, so they failed todisplay satisfactorily the color of tea itself. Tea liquor in the cases of mineral water wasoxidized due to the calcium and magnesium in them, thus a darker color, so contrarily itdisplayed the tea color better. The tea liquor extracted from tap water had the worst quality,carrying a disturbingly rusting smell.After different sterilization conditions, tea in different degrees of browning, lighttransmission rate was also reduced. Through the high-temperature method, black teabeverage had severely damaged, the microwave sterilization had a certain impact on the tea. The results of ultraviolet sterilization declared that it had less influence on the tea qualitythan the high temperature way. Maximum Tea polyphenols could be reserved and leastbrowning and precipitate was formed in the process.