For measuring the non-resistant starch, the supernatant solutions from centrifugation
of the initial incubation and the supernatants obtained from subsequent two 50%
ethanol washings were put together in a volumetric flask and filled up to 100 ml with
100 mM sodium acetate buffer (pH 4.5). Then, 0.1 ml of each solution were
transferred into glass test tubes, 10 µl of diluted AMG solution were added and
incubated for 20 min in a water bath at 50 °C. Subsequently, 3 ml of GOPOD reagent
were added and incubated again at 50 °C for 20 min. The samples were transferred
into macro-cuvettes and for each sample the absorbance at 510 nm were read against
the reagent blank. The non-resistant starch content was calculated according to eq. 9.