Continuous production of wheat gluten peptide with foaming properties using immobilized enzymes

Gluten peptides are prepared using limited hydrolysis of wheat gluten, resulting in improved solubility and physico-chemical properties. In general, the hydrolysis is performed using a batch-wise process. In this study, we developed a bioreactor system that can continuously produce gluten peptides with foaming properties. Two kinds of acid protease, pepsin and rapidase, were immobilized on porous chitosan beads. The partial deamidation of gluten in advance increased initial velocity of hydrolysis by immobilizing protease and also worked to enhance foaming properties. A packed-bed reactor filled with immobilized protease was designed, and operating parameters were optimized. The optimized conditions were as follows: pH, 3.0; temperature, 40degreesC; substrate concentration, 40 mg/ml; and space velocity, 2.0 h(-1). Based on these results, a bench-scale reactor was manufactured to determine the stability of continuous operation. The half-life of the reactor was approximately 45 days, and both productivity and quality were stable and excellent.