The effect of three gums on the retrogradation of indica rice starch

Abstract

Retrograded starch (RS3) was produced from indica rice starch with three kinds of gums (konjac glucomannan, KGM; carrageenan, CA, USA; and gellan, GA, USA) by autoclaving, respectively, and the effect of the gums on the retrogradation behavior of starch was estimated. The influences of polysaccharide concentration, sodium chloride concentration, autoclaving time, refrigerated time, and pH value on RS3 formation were discussed. Except for sodium chloride's persistent restraint on RS3, the others all forced RS3 yields higher at first, but lowered it after the peak value. The influencing sequence of these impact factors was: sodium chloride concentration > polysaccharide concentration > autoclaving time > refrigerated time > pH value. The results also proved that in the three gums, KGM plays the most significant role in RS3 changing. It was concluded that the incorporation of each of these three gums into starch, especially KGM, results in an increase or decrease of RS3 under different conditions. This phenomenon could be taken into consideration when developing starchy food with appropriate amount of RS3. © 2012 by the authors; licensee MDPI, Basel, Switzerland.