2.3. Trypsin inhibitor activity (TIA)
Trypsin inhibitor activity was assayed according to the Kakade, Simon, and Lierer (1969) using BAPA (N-benzoyl-dl-arginine-P-nitroanilide hydrochloride) and trypsin, type III, from bovine pancreas. TIA, expressed as trypsin inhibitor units per milligramme of sample (TIU/mg sample) was calculated from absorbance read against blank in a spectrophotometer. One trypsin unit is defined as an increase of 0.01 for an absorbance unit at 410 nm per 10 ml of reaction mixture.