Isolation And Purification Of Rhamnose From Products Of Rutin-rhamnosidase Hydrolysate

In this paper,the rhamnose was obtained from the hydrolysis of rutin by rutin-a-rhamnosidase(RhaR)from Absidia sp.R9g.The separation of hydrolysate containing rhamnose and isoquerctrin was separated by using macropore resin separation method.Then the ion-exchange resin and activated carbon used for the decoloration of rhamnose solution were investigated.Finally,the rhamnose product was further purified by the method of crystallization,and the crystal conditions was optimized,which will provide a basis for further research of rhamnose.When hydrolytic product from 24 g rutin was separated by macropore resin SP207,4.18 g crude rhamnose was obtained after concentration with a yield of 17.4%.By comparing the two decoloration methods using activated carbon and macropore resin,the activated carbon was selected as the decolorizer.And the optimum condition for decoloration of rhamnose solution with the activated carbon was as follows:4%active carbon,temperature was 30℃,pH value was 6,time was 30 min,decolouration ratio was 70.36%.In the crystallization,the rhamnose solution was supersaturation in aqueous solution when its concentration was 0.4g/mL,and the crystals were separated slowly with water evaporation.Then the phenomenon can be found that the more water was evaporated,the faster crystals were separated and the higher crystal yield was obtained.By stalling in vacuum drier,colorless and transparent crystal can be obtained.Finally,effect of adding organic solvent(methanol and ethanol)was investigated.And adding organic solvent can promote the rate of crystallization,but the pigment will be dissolved out with crystal,which can influence in the purity of rhamnose.Finally,the optimum condition for crystallization was as follows:the concentration of rhamnose aqueous solution was 0.4g/ml,crystallization method was accelerating evaporation,the yield of crystal was 31.0%.