The effect of canola protein extraction conditions on the kinetic parameters of a two-site extraction model

Abstract. Canola meal is an underutilized, protein rich by-product of the growing bio-diesel and oil production industries. Valorization of the meal is important for profitability of canola processing operations therefore knowledge of the extraction mechanism and optimization of process parameters as well as limiting factors of operation is important. To this end, the effect of alkaline extraction parameters (alkaline concentration of 0.02 M to 0.08 M; particle size, 16-120 mesh and temperature 25 - 55 °C) on the kinetic coefficients of a two-site kinetic model for protein extraction were studied. The model assumes parallel fast and slow processes of protein release from the meal. Protein yield and reaction rate increased with increasing alkaline concentration, increasing temperature and decreasing particle size. Protein release by the slow process was rate determining, however its limiting effects on the yield and rate were reduced with conditions favorable for extraction. Change in particle size had the greatest effect on yield among all extractions conducted, with a 295.262 mg·g-1 increase in yield between particle sizes of 16-35 mesh and 60-120 mesh. A maximum yield of 821.632 mg·g-1 was obtained at a particle size of 60-120 mesh, 0.06 M sodium hydroxide at 25 ºC.