Flow properties of faba bean protein concentrates were studied using
Coaxial rotational viscometer to measure the effect of concentrations (9%.12%.15%
and 18%) and temperatures (30·, 40·, 50·. 60" and 70·C) on their meological
parameters. The protein concentrate samples were prepared from raw seeds or from
seeds subjected to soaking..gerrnination, autodaving and microwaving. Results
showed that the protein concentrates followed a non-Newtonian behaviour with a
pseudoplastic nature.' Heating treatments (autoclaving and microwaving) of
germinated taba bean seeds resulted in protein concentrates with high viscosity
values. Thtl rheological parameters (K and "To) increased exponentialy with increasing
concentrations and showed reduction with increasing temperature up to eo·c. At
70·C a revers1b18 effect has been observed, where the viscosity and constant values
has been increased consequently the change in the structure of protein molecules.
Calculated activation energy values using the Arrhenius approach were in the range
of 5.96 to 18.65 kJImoI. Different rheological models were employed and the model of
Herschel-Bulkley was foun<1 to .be the most suitable formulation representing the
rheological bet)aviour Qf mba bean protein concentrates. Fitted equations developed
to predict !be COI'nbinOO effect of concentration and temperature on viscosity of the
tested samples were found to be adequate predictions, that may be used to estlmate
vIscoSity values during procesSing. .