Production of Boiling‐Stable Granular Resistant Starch by Partial Acid Hydrolysis and Hydrothermal Treatments of High‐Amylose Maize Starch

Abstract

ABSTRACTThe purpose of the present work was to examine whether partial acid hydrolysis (PAH) of a high‐amylose maize starch (ae‐VII) would enhance the effects of hydrothermal treatments to produce granular resistant starch (RS) that is stable to further heat treatment at atmospheric pressure. PAH ae‐VII starches were prepared by heating 35% (w/v) suspensions with 1% (w/w) HCl at 25°C for 6, 30, and 78 hr. Native and PAH starches were then treated by annealing (ANN) or heat‐moisture treatment (HMT). ANN was done at 70% moisture at 50, 60, or 70°C for 24 hr, and HMT was done at 30% moisture at 100, 120, or 140°C for 80 min. RS that survives boiling during analysis was determined by a modification of the AOAC method for determining total dietary fiber. RS was also determined by the Englyst method. Little change in the gelatinization enthalpy was found for ae‐VII starch after PAH, ANN, or HMT as individual treatments. After PAH, either ANN or HMT led to decreased gelatinization enthalpy. HMT and ANN alone increased boiling‐stable RS but decreased total RS. After PAH of ae‐VII, either ANN or HMT tended to increase the yield of boiling‐stable granular RS, with the greatest yield (≤63.2%) observed for HMT.