| Tea polysaccharide (TPS)is a kind of important active composition of tea which has many special physiological functions. This paper mainly studied brick tea produced in Sichuan Ya an and related the extraction and purification processes of the tea polysaccharide and analyzed its chemical ingredients. The main results were shown as follows:1. By means of orthogonally rotational combination design, a four-factor (temperature, time, ratio between tea and water, pH) substrate cultivation experiment was conducted using brick tea. The regression equations of the relationship between temperature, time, ratio between tea and water, pH and extraction rate of tea polysaccharides (TPS) were established. The results indicated that extraction rate of TPS was affected obviously in successive order of pH, temperature, ratio between tea and water and time. In range of experiment, extraction rate of TPS was increased obviously when pH and temperature were in higher levels, and the interaction of pH and temperature to the ratio between tea and water was significant, but the change of time and ratio between tea and water had less influence effects on extraction rate of TPS. Considering high extraction rate and activity of TPS, the extraction conditions were optimized by frequency analyses that were 74.06-80.74℃temperature, 69.56-79.58min time, 38.49-42.59 ratios between tea and water, 7.411-8.284 pH.2. Results of Ultrasonic assistant extraction orthogonally design indicated: the extraction rate of TPS was affected obviously in successive order of ratio between tea and water, time, power and temperature in experiment range. Synthetical plan included power of extraction was 360W, ratio between tea and water was 1:50, time of extraction is 35 min and temperature of extraction was 60 °C by multi-comparison of experimental factors.3. With the ethanol concentration increasing, the obtained ratio of TPS was obviously increased and content of sugar increased firstly, but reduced lately. The optimum range of ethanol concentration is 75%-85%. The obtained ratio of TPS was increased with the ratio between tea and water increasing, the optimum ratio between tea and water is 1 - 2. Content of sugars in TPS was obviously increased after desertification of H2O2, and content of protein had little reduction. Sevag de-protein operates is the best way in the three ways of de-protein, the optimum tennic acid concentration is 16g/L.4. Results of study on influnce factor of TPS'activities: TPS' s cleaning effects of O2 began to reduce when temperature exceed 60℃ and reduced obviosly when temperature exceed 70℃. TPS' scleaning effects of ? OH and O2 rose firstly and reduced subsequently with the accretion of pH. Activities of TPS could be kept highly when pH was 6-7. Ultrasonic assistant had no disadvantageous effects on quality of TPS , no obvious effects on TPS' s cleaning effects of ? OH and had advantageous effects on TPS' s cleaning effects of O2 . The reasons may be that Ultrasonic assistant extraction can shorten time of extraction so that TPS can't be heated up excessively. TPS's cleaning effects of ? OH enhanced gradually with the processing carrying on, and exceeded obviously in the process of fermentation.5. By elementary analyses, their compositions of monosaccharides were gained: Ara, Man, Glc, Gal ,Gal-ald , Xyl and Rib. TPS had Extra absorb in rang of 260-280nm by UV spectrum analyses which indicated there're protein in TPS.6.The components of brick tea changed obviously in the processor fermentation. Contents of Soluble solid(SS), amino acid , total sugars increased in some degree from raw material to fermentation material. Contents of amino acid in brick tea were 1590.00mg/100g, higher in the processof fermentation than other process. Contents of tea polyphenols (TP) and catechins reduced gradually with the processing carrying on, and the reduction of catechins above 50%.7. The extration rate of microelements had obvoius advance from raw material to fermentation material. Compared to raw material, the extration rate of Se, Mn, Zn, Mo, Cu in Kang zhuan tea exceeded 2.98%, 7.62%, 19.34%, 8.64% and 6.48% respectively. The ratio of microelements content of TPS to its of soluble solid in Kang zhuan tea was that Se was 5.42 times, Mn was 1.45, Zn was 0.64, Mo was 2.62, Cu was 1.12.
|
PDF Full Text Request