Preparation And Characteristics Of Maltodextrin With Low Dextrose Equivalent

The characteristic of starch is affected greatly by protein residual in starch. The purification of starch to remove the protein, therefore, is one of the main factors for its application. The objective of this study was to investigate an optimum parameters for isolation and purification of rice starch with the method of alkali digestion. In a 3×3 factorial modeling experiment, the result showed that the optimum conditions for alkali digestion were 0.4% (w/v) NaOH, 30% (w/v) starch slurry and 4 h digestive time. Under this condition, the protein residual in the purified starch was 0.34% (w/w), lower than Yamamoto's method, and the recovery of rice starch was 71%, 6% higher than Yamamoto (65%). Swelling power and solubility of the purified starch were greatly improved after removal of protein compared with the unpurified rice powder.The recrystallizaion method was used for seperation and purification of amylose and amylopectin from rice starch. Purities of these two components were examined by iodine affinity. The results showed that 5 times recrystallizaion by forming amylose-butanol complex can get pure amylose; 3 times recrystallizaion to decant amylose can get pure amylopectin.Rice maltodextrins with low dextrose equivalent were prepared by a -amylase digestion of a starch paste. Using Multiple regression analysis, a second-order model was abtained with a correlation coefficient 0.982 (p ≤ 0.05). Analysis of the response surface showed that dextrose equivalent (DE) 0.75-5.72 were prepared at 95℃ by altering the amount of enzyme (1-3 ml), digested time (10-15 min) and the concentration of starch paste (10-20%). There are different between various maltodextrins of low dextrose equivalent in hygroscopicity freeze-thaw stability and gelatin capability, but no difference in specific volume...