Abstract:Enzymatic conditions for preparing small peptides from rice proteins with alcalase 2.4L were optimized by single factor experiment and the enzymatic kinetics was established. The optimal enzymatic conditions were as follows: temperature 55 ℃ pH 8.5, enzyme-substrate ratio 0.096 AU/g (substrate). Product inhibition was observed during the enzymatic hydrolysis process, but no substrate inhibition was observed within tested substrate concentration (<90 g/kg). The enzymatic kinetic parameters were: k2 = 0.28 mmol/(AU·min), Km = 5.76 (g·min)/mmol, and Vmax = 0.67 mmol/(kg·min). The kinetic enzymatic equation was: 1/V0 = 56.29/[S0][E0] + 1/0.28[E0]. After enzymolysis for three hours under the optimal enzymatic condition, the degree of hydrolysis (DH) reached 16% and the hydrolysates content with molecular weight between 264~584 u reached 94%. The molecular weight distribution of hydrolysates was barely changed after 3 h enzymolysis.
