Production of Brassica carinata protein hydrolyzates with a high Fischer's ratio using immobilized proteases.

Brassica carinata protein isolates were hydrolyzed using the digestive enzymes trypsin, chymotrypsin, and carboxypeptidase A in order to obtain hydrolyzates with a high Fischer's ratio. The proteases were immobilized using two glyoxyl-agarose supports of different porosity, 4 and 10% agarose gels, in order to evaluate the effect of substrate diffusion into the support containing the enzyme on the hydrolytic process. Reaction time, substrate concentration, and the enzyme to substrate ratio were optimized in an attempt to increase the Fischer's ratio in the resulting hydrolyzates. Gel filtration chromatography of a hydrolyzate with a degree of hydrolysis of 36% yielded a fraction that represented 31% of the total hydrolyzed proteins and had a Fischer's ratio of 28.3 with a phenylalanine + tyrosine content below 1.5%. This material could be used for preparing special diets when there is a need to increase the supply of branched amino acids and/or reduce the intake of aromatic amino acids.