A rapid quantitative method for polysaccharides in green tea and oolong tea

Tea polysaccharides (TPS) from five different kinds of tea contain similar composition of sugars and amino acids. Polysaccharide part of TPS is mainly composed of arabinose, galactose and glucose with the approximate molar ratio of 1:1:0.5. Protein part of TPS is composed of 16 normal amino acids among which Val, Ala, Gly, Glu are the major proportion. Based on the results, the purified TPS was used as the calibration standard in phenol sulfuric acid reaction for the calibration curve that was constructed by plotting absorbance versus mass of TPS with a correlation coefficient of 0.9961. In the developed method, TPS mass recovery ranges from 84.88 to 95.7% with a relative standard deviation of 5.53%. It is found that the developed method is simple, rapid, reliable and is ideally suitable for quantifying TPS from green tea or oolong tea.