Isolation and characterization of a soluble branched starch fraction from corn masa associated with adhesiveness

ABSTRACT A water-soluble starch fraction isolated from corn masa and identified by HPSEC as predominantly fragmented amylopectin was highly correlated in amount to both masa adhesiveness (r = 0.890, P < 0.01) and cook time (r = 0.957, P < 0.01). The molecular weight of the component ranged from approximately 6.4 × 105 to 1.2 × 106, based on HPSEC column calibration with pullulan standards. Debranching with isoamylase illustrated that the structure of the soluble masa starch component was highly branched with a similar debranched profile to native amylopectin. Further analysis revealed that a minor amount of amylose was present in the second half of the broad HPSEC peak containing the fragmented amylopectin component. There was a high second-order correlation (r = 0.998, P < 0.01) between the absorbance at the wavelength of maximum absorbance (λmax) of the soluble fraction from masa (527–532 nm) and masa adhesiveness, indicating that a rapid assay for masa adhesiveness could easily be developed. Increasing...