Decolorization and deproteinization of pullulan from fermentation broth

There are many problems in decolorization and deproteinization of pullulan from fermentation broth,such as large toxic organic reagents usage,high repetition times and easy polysaccharide degradation etc. To solve these issues,study for the decolorization and deproteinization of pullulan was developed through static adsorption tests of D4020 macroporous resins,diatomite and attapulgite. This paper investigated how the ratios of decolorization,deproteinization and polysaccharide recovery changed along with the adjustments of adsorption time,temperature,p H and dosage. The results showed that these three kinds of adsorbents all performed well in adsorbing the impurities,and diatomite was the most suitable one.Based on the single factor experiment,diatomite was then chosen for the orthogonal experiment.The results showed that the optimal processing conditions were as follows: 60 min adsorption time,35℃ adsorption temperature,p H value 3.2 and 1.6% diatomite. Under such conditions,the decolorization ratio was 80.17%,the deproteinization ratio was 76.28% and the polysaccharide recovery ratio was 89.82%.