Study upon Discoloring Conditions of Radix Rehmanniate Polysaccharide by Using Macroporous Adsorbent Resins

To compare the influence of different type macroporous resinsin decolorizing effect of radixrehmanniate polysaccharide extract, and to confirm the best decolorizing technical parameter. Compare the influence of macroporous resins of six different polarities HP20,DM130,X-5,S-8,D-101, and NKA-II 6 in decolorizing effect and content of radix rehmanniate polysaccharide extractthrough static adsorption, select the one with best decolorizing effect under the same experiment conditions, and optimize its decolorizing parameters with orthogonal experiment. The L9(43)orthogonal experiment took time(A), temperature(B), material ratio(C), surge time(D) as the observation factors, and polysaccharide decolorization rate(%) and polysaccharide remaining rate(%) as the indexes. Of the six kinds of macroporous adsorptive resins, DM130 owns the best decolorizing effect for radix rehmanniate polysaccharide extract. From the orthogonal experiment, the best parameters of DM130 was found: temperature 30 °C, volume ratio of polysaccharide and resin 4 ∶ 1, surge time 3 minutes, reaction time 5 hours, decoloration rate 74.68 %, polysaccharide loss rate 26.21 %. Best decolorizing effect can be got for radix rehmanniate polysaccharide extract with DM130 macroporous resin.