Study On Preparation Of Isomaltooligosaccharide From Sweet Potato Reside

Sweet potato residues, as sweet potato by-products with low economic values, are regarded as feeds at most time or are discharged directly as wastes by enterprise. Not only does that cause waste of the resources, but also pollutes the environment. In fact, sweet potato residues contain lots of nutrients. The content of starch can reach 32% to 53% and the content of cellulose can reach 22%. The study regards sweet potato residues as materials, aims to finish the preparation of functional oligosaccharides by technology of enzymatic hydrolysis. The the main conclusions are as follows:1. The study regards sweet potato residues as matetials, using complex enzyme and single enzyme respectively, finishes the preparation of isomaltooligosaccharide and cellooligosaccharides by the enzymolysis of starch and cellulose in sweet potato residues, then oligosaccharide which were made by two techniques were analysed and compared by HPLC. The results show that the content of the preparation of isomaltooligosaccharide is 72.86 mg/ml by use of complex enzyme, while the content of the preparation of cellooligosaccharides is 1.30 mg/ml by use of single enzyme. Thus, the study chooses sweet potato residues to prepare isomaltooligosaccharide and optimizes the technology.2. The liquefaction technology and optimum liquefaction DE value of using sweet potato residues to prepar isomaltooligosaccharides. The effects of the liquefaction substrate concentration, liquefaction temperature and enzyme amount on the yield of isomaltooligosaccharides with some single-factor experiments are studied. Then the liquefaction process optimization by orthogonal experiments. The results show that the best value of liquefied is 17, the concentration of liquefaction substrate is 15%, enzyme concentration is 0.1 %, and the content of the preparation of isomaltooligosaccharid is 58 % when the time reaches 2 hours.3. The saccharification and turn glycosides technology optimization by the content of isomaltooligosaccharides as an index of using sweet potato residues to prepare isomaltooligosaccharide. The effects of the time of saccharification, the combination and concentration of enzyme on the yield of isomaltooligosaccharides with some single-factor experiments are studied. The results show that the time of saccharification technology is 4 hours, the combination of enzyme including fungal α-amylase(0.00918g), β- amylase(0.00312g), and pullulanase(15μL), and the content of the preparation of isomaltooligosaccharide can reach 58%.And we also research the effects of enzyme concentration and the reaction time on the yield of isomaltooligosaccharides with all-factors experiments are studied. The results show that the optimum enzyme concentration of turn glycoside is 0.0096g/15 g, the optimum time of turn glycoside for sweet potato residues is 28 hours.4. The research is about isomaltooligosaccharide syrup decolorizing and removing impurity treatment technology. The effects of decolorization time, decolorization temperature and the decolotizing agent adding amount on the yield of isomaltooligosaccharides with some single-factor experiments are studied. And the research takes the decolourization ratio of isomaltooligosaccharide syrup as a main index, applies Design Expert to design and analyse. The results show that it is effective to choose the activated carbon with high safety and strong adsorbability. The time of decolourization is 37.48 minutes, and it adds carbon 1.31g/100 mL. When the temperature of decolourization is 45.41℃, the decolourization ratio reaches 47.2%.