Then Flavourzyme (4.2%, w/v) was added to hydrolyze the corn gluten meal for another 66 min. At the end of the hydrolysis period,the mixture was heated in boiling water for 10 min to inactivate the proteases. The hydrolysates were then centrifuged at 10,000g for 10 min at 4 C. The obtained supernatant was ultra-filtered through a membrane with a cut off molecular weight of 30 kDa. This process yielded two fractions: retentate (fraction 1, represented hydrolysates >30 kDa) and permeate
(MW < 30 kDa). The permeate was further ultra-filtered through a membrane with a cut off molecular weight of 10 kDa to obtain the second retentate (fraction 2, represented hydrolysates between 30 and 10 kDa) and permeate (fraction
3, represented hydrolysates