Corn gluten used in this research was obtained from Cargill
(Istanbul, Turkey). The enzyme used in this work was Alcalase
2.4 L, a bacterial endo-peptidase produced by Bacillus licheniformis,
obtained from Novozymes (Istanbul, Turkey).
Hydrolysis experiments were carried out in a 200 ml jacked
reactor with magnetic stirring and pH and temperature control.
During the hydrolysis the pH was maintained by the
addition of 0.2N KOH. In this study, all experiments were carried
out at least in duplicate and the deviation between trials
was within ±5%. For determination of the free -amino groups
both TNBS (Adler-Nissen, 1979) and OPA (Nielsen et al., 2001)
methods were used. For each sample, the assays were carried
out in triplicate and their averages were taken