Extraction Of Water-soluble Polysaccharides From Apple Pomace And Its Characteristics

1. The effect of temperature, time, solid-solvent ratio on extraction rate of water-soluble polysaccharides of apple pomace had been researched by quadratic regression rotational combinational design. The results indicated that extraction rate of apple pomace was affected by factors from more significant to less with temperature, time and solid-solvent. The best extraction conditions were at: temperature 84℃, time 4.1h, solvent and solid ratio 1:52. The yield of the polysaccharides of apple was 14. 94% under above conditions.2. The better conditions of ultrasound-assisted extraction were as follows: power 180W, temperature 70℃, time 120min, solvent and solid ratio 1:30, by orthogonal test. The order of the extraction factors from more significant to less was as follows: temperature>power> solid liquid > time.3. The studies of apple polysaccharides precipitation process showed that the better conditions were concentrated four-fold and adding ethanol of 4 times. Increasing the extracted times had no impact on the extraction rate, considering the efficiency and economy of extration, extracted one time was chosen.4. Sevage, TCA and sevage +TCA methods had been used for removing protein of apple polysaccharides. The results showed that: sevage+TCA method had the best treatmnet, protein removal rate of 51.68%, lost polysaccharides rate of 11.49%; followed by TCA, the worst treatment was used by only sevage, the lowest removal rate of protein and the highest lost polysaccharides rate.5. Active charcoal and porous resin had been used for the apple polysaccharide decolorization.The optimum conditions of decolorization with active charcoal were as follows: temperature of 40℃, time 40min, pH4, the amount of 2%, the decolorization and retention rate of polysaccharide were 71.31% and 62.79%, respectively; the better conditions for porous resin decolorization were as follows: temperature 50℃, time 80min, pH5, the amount of 2%, the decolorization and retention rate of polysaccharide were 82.69% and 63.77%, respectively.6. The studies of rheological properties of polysaccharides showed that the viscosity of apple polysaccharides was decreased with the increase of temperature, decreased with its weight percentege, decreased with the increase in pH and salt concentration had no impact on the viscosity of apple polysaccharides. 7. The molecule weight of apple polysaccharides had been divided into five parts by ultrafiltration. The volume ratio of different molecular weight was: 40.25:8.63:6.75:22.5:21.87; mass ratio was: 56.27:9.5: 6.8:12.5:11.65:3.28.8. The research of apple polysaccharide antioxidant activity indicated that it had effect on eliminating hydroxyl radical and superoxide anion, and has a certain reducing power; the best part was molecular weight more than 300 thousands, but its fuction of antioxidation was lower than Vc.