A pulverized sample is treated with heat resistant enzymes: alpha-
amylase, amyloglucosidase and protease, under defined pH
and temperature. Heat resistant alpha-amylase turns starch into liquid
and optimises condition for the next phase where enzyme
amyloglucosidase hydrolise starch into glucose. In the final step
proteolytic enzyme hydrolises proteins into soluble amino acids
and short-chain peptides. After the enzymatic treatment has been
completed the sample is corrected for possible mineral and nitrogen
residue. Total dietary fibre is measured by gravimetric
analysis.