Performance of enzymatic wheat gluten hydrolysis in batch and continuous processes using Flavourzyme

- Inhibition of Flavourzyme™ by l-amino acids was studied.
- l-cysteine inhibited Flavourzyme™ strongest.
- An enzyme membrane reactor system improved the product-enzyme ratio.
- The enzyme membrane reactor was operated for nine days and 80% of the initial space-time-yield remained.

The aim of this study was to investigate the process performance of wheat gluten hydrolysis with Flavourzyme in the conventional batch and in an enzyme membrane reactor system. The release of amino acids and peptides from wheat gluten using Flavourzyme in a batch process (T 50 °C, pH 5) is limited due to product inhibition. Investigation of Flavourzyme inhibition kinetics by l-amino acids revealed that the strongest inhibition was observed by l-cysteine. Thus, application of an enzyme membrane reactor with continuous product removal and substrate and enzyme retention was assessed. The highest productivity in the enzyme membrane reactor system was found using a 10 kDa molecular weight cut-off polyethersulfone membrane. This resulted in an increased product enzyme ratio from 2.1 mg product/nkat in the conventional batch process to 4.9 mg product/nkat with the enzyme membrane reactor after 20 h. The enzyme membrane reactor retained 80% of the initial space-time yield (STYinit 5 g/L/h) after nine days.