The Study On The Production Of Isomaltooligosaccharides With Rice Starch By Enzyme Method

Isomaltooligosaccharides (IMO) is an important functional oligosaccharide, it has many good processing properties and physiological functions such as adjust intestinal microecological balance, enhance immunity and so on. IMO has been widely used in food, medicine, feed, etc. At present, the most of broken rice produced by the rice processing enterprises was sold to feed enterprise, its value dose not fully developed. Strengthening the research of development broken rice and enhance its additional value is a vital problem in food processing industry. To study the production of isomaltooligosaccharides with rice starch has important academic value and practical significance.At the very beginning of this paper, three different kinds of rice starch separation methods (alkaline, SDS and enzymatic method) have been compared, and the enzymatic method has been proved to be the best one. Three different varieties of rice starch have been separated by enzymatic method, and the total starch contents were all above 94.5%, while the protein contents were below 1.07%, the breakage rates of starch granule were below 2%. And then, the amylose contents, hydrolysis forces, pasting properties and gel texture properties of these three different starches have been studied. The amylose contents of indica starch, japonica starch and glutinous starch were 19.7%,13.9% and 1.7%. The hydrolysis abilities were different with the variety, and the japonica starch has a significantly (P<0.05) higher hydrolysis ability than that of indica starch and glutinous starch. In terms of pasting properties, glutinous starch has the highest peak viscosity and breakdown value, while indica starch has the highest hot viscosity, final viscosity and pasting temperature. Except the pasting temperature and steback value, the parameters of pasting properties are correlated with amylose content. The peak viscosity has positively related to breakdown value and amylose content, and the hot vicosity, final viscosity and peak viscosity time were negatively correlated with amylose content. In the gel texture properties, the hardness of indica starch was significantly higher than japonica starch and glutinous starch, while the viscosity and fragmentation of indica starch were significantly lower than the other two starches. The appropriate liquefied DE value of producing isomaltooligosaccharides from rice starch were examined with the contents of functional sugar such as isomaltose (IG2), panose (P) and Isomaltotrise (IG3) as index. The DE value around 12%was determined as the optimal DE value which theω(IG2+P+IG3) is higher, together with easy filtration in further saccharification and transfer glucoside. Based on this, the processes of producing isomaltooligosaccharides from three kinds of rice starch were optimized with|12-DE|as index. the optimal liquefying process of producing isomaltooligosaccharides by enzyme method in indica rice is as follows:liquefying 12min, substrate concentration 30%, Thermostable a-Amylase dosage20 U/gD, stirring rate 120r/min, liquefying temperature 95℃and a natural pH; while the optimal process for japonica rice is liquefying 12min, substrate concentration 25%, Thermostable a-Amylase dosage15 U/gD, stirring rate 140r/min, liquefying temperature 95℃and the pH was on the experimental conditions; however, it was difficult to liquefy waxy rice and to achieve an appropriate DE value range.Taking the content of three functional sugars including isomaltose(IG2), panose (P) and isomaltotriose (IG3) in prepared sugar liquid as index to discuss the optimized saccharification and transfer glucoside condition of madding IMO using rice starch. The indica rice starch optimized saccharification and transfer glucoside condition is:saccharification enzyme ratio is 0.2 U/gDS fungus a-amylase,0.1 U/gDSβ-mylase and 0.1 U/gDS Pullulanase. The saccharification and transfer glucoside way is partional saccharification then transfer glucoside.The dosage of trans-glucosidase is 1.0U/gDS. Reaction condition:36h. pH5.5,55℃.The japonica rice starch optimized saccharification and transfer glucoside condition is: saccharification enzyme ratio is 0.2 U/gDS fungus a-amylase,0.1 U/gDSβ-mylase and 0.2 U/gDS Pullulanase. The saccharification and transfer glucoside way is partional saccharification then transfer glucoside. The dosage of trans-glucosidase is 1.OU/gDS. Reaction condition:36h, pH5.5,55℃.