Effect of Oligosaccharide Syrup Addition on the Retrogradation of a Korean Rice Cake (Karedduk)

Abstract

Effects of the addition of three commercial oligosaccharide syrups into a Korean rice cake (Karedduk) on the textural characteristics and retrogradation of the rice cake were examined during the storage for 5 days at and . Each syrups contained maltose (M75), isomaltose and panose (HL), or maltotetraose (G4) as major sugars. The increment (rates) in gumminess, hardness and chewiness during the storage were significantly reduced by replacing rice flour (up to 10%) with the oligosaccharides. The retardation in the textural changes by the oilgosaccharides was more significant when the rice cake was stored at than at . Among the three types, HL exhibited most effective in retarding the textural changes. Thermograms by a differential scanning calorimeter (DSC) showed that the oligosaccharide increased the onset temperatures and enthalpy for the starch melting, but the recrystallinity measured from the enthalpy ratio before and after the storage was significantly reduced by the presence of the oligosaccharide. Especially with 5% HL, the recrystallinity was significantly low (72.7%) compared to rice cake without HL (88.1%). Therefore, HL had great efficiency in retarding starch retrogradation as well as textural changes of the rice cake during the storage.