Studies On The Abstraction And Using Of Sweet Tea Glucoside And Tea Polyphenol From Guangxi Sweet Tea

Rubus Suavissmus S Lee is an innocuous and health protection plant with high sugar content and low caloric value. It is reported that the major bioactive components of Rubus Suavissmus S Lee are rubusoside, tea polyphenol and bioflavonoid. This dissertation focused on the extraction and purification of rubusoside from Rubus Suavissmus S Lee as well as the tea polyphenol from the debittering residua of crude rubusoside. The obtained results should be useful for the exploiture of Rubus Suavissmus S Lee. The results are as follows:1. The comparative study on the extraction solvent and extraction strategies indicated that ethanol solution was the best extraction solvent, while using ultrasound-assisted extraction could achieve higher extraction efficiency. The extraction efficiency of rubusoside was improved significantly with a lower extract temperature, shorter extract time by using the ultrasound-assisted extraction technique. The results of orthogonal test on temperature, extraction time and solvent/sample ratio have shown that the following experimental conditions were selected as optimum: the concentration of ethanol was 30%, solvent/sample ratio 30/1 (v/w), temperature 40℃; extraction time 20 min, repeated once, with an extraction efficiency of 5.6% under the ultrasound wave frequency of 40 KHz.2. The crude rubusoside is somewhat bitter and could be debittered by limewater with a concentration of 0.1 mol·L^-1. The obtained debittering ubusoside could be used instead of sugar in the production of sugarless yoghourt with a good taste, low caloric value and it is cost-saving.3. The content of tea polyphenol in the debittering ubusoside is about 45-50%. The tea polyphenol with a purity of 72.12% was obtained by purified with DM-301 macroporous resins and eluted with 700 mL·L^-1 of ethanol. The results of the inhibition of the obtained tea polyphenol on the deleterious microorganism have shown that it is an effective inhibitor for the food bacteria and a slight effective yeast inhibitor while has no inhibition on mildew.