Determination of resistant starch content
The resistant starch (RS) content was measured using the test kit from Megazyme International
Ltd. (Ireland, UK). The method was comprised of the following steps: incubated samples with
pancreatic α-amylase containing α-amyloglucosidase at 37oC for 16 h to hydrolyze digestible starch,
treated the precipitates with 2 M KOH to solubilize RS, incubated samples with amyloglucosidase at
50oC for 15 min, and determined glucose contents using the glucose oxidase/peroxidase assay. The RS
content was calculated as glucose x 0.9.