“…Starch was hydrolyzed by HCl, porcine pancreatic ␣-amylase (PPA, Sigma A3176, 23 U/mg), or Aspergillus niger amyloglucosidase (AAG, Sigma A7095, 300 U/mL) using the methods of Gao et al (2014) and Li, Vasanthan, Hoover, and Rossnagel (2004) with some modifications. For HCl hydrolysis, 20 mg of starch was incubated in 2 mL of 2.2 M HCl in an Eppendorf ThermoMixer at 35 • C with continuous shaking (1000 rpm) for 4 d. For PPA hydrolysis, 10 mg of starch was incubated in 2 mL of enzyme solution (0.1 M phosphate sodium buffer, pH 6.9, 25 mM NaCl, 5 mM CaCl 2 , 0.02% NaN 3 , 50 U PPA) in an Eppendorf ThermoMixer at 37 • C with continuous shaking (1000 rpm) for 12 h. For AAG hydrolysis, 10 mg of starch was incubated in 2 mL of enzyme solution (0.05 M acetate buffer, pH 4.5, 5 U AAG) in an Eppendorf ThermoMixer at 55 • C with continuous shaking (1000 rpm) for 12 h. After hydrolysis, the starch slurry was quickly centrifuged (5000 × g) at 4 • C for 5 min.…”