Modelling of the inactivation kinetics of the trypsin inhibitors in soy flour

The inactivation kinetics of trypsin inhibitors (TIs) in soy flour was meas ured over a large range of temperatures (80-134 degrees C) and moisture con tents (0.08-0.52 g (gds)(-1)). The inactivation of TIs showed a two-phase i nactivation behaviour. The influence of moisture content on the inactivatio n rate of TIs was large at moisture contents < 0.30 g (g ds)(-1). Six diffe rent inactivation kinetics models were used to describe the decrease of the trypsin inhibitor activity at constant moisture content. The models were c ompared statistically using a corrected Akaike information criterion, The m ost parsimonious models at moisture contents less than or equal to 0.30 g ( gds)(-1) were the model with two first-order reactions each for a different TI group, and the model with an irreversible inactivation of a native TI t o a partially active intermediate TI, followed by a denaturation step. The nth order reaction model was favoured at moisture contents greater than or equal to 0.40 g (gds)(-1). The kinetics parameters of the model with two fi rst-order reactions were modelled as a function of moisture content. The ov erall inactivation model described well the experimental inactivation data of TIs, (C) 1999 Society of Chemical Industry.