Normal rice (Pathum Thani 60) and waxy rice (RD 6) were provided from Pathum Thani Rice Research Center, Thanyaburi, Pathum Thani, Thailand. Normal corn (sweet type), waxy corn and normal potato were purchased at a local market in Bangkok, Thailand. Waxy potato starch was provided from the National Starch Food Innovation. Porcine pancreatic α-amylase (EC 3.2.1.1, 28 U/mg solid) and amyloglucosidase (EC 3.2.1.3, 300 U/mL) were purchased from Sigma–Aldrich, Inc. (St. Louis, MO). GLUCOSE liquicolor complete kit was purchased from Human GmbH (Wiesbaden, Germany).