Immobilization of trypsin on spent grains for whey protein hydrolysis

The best activity retention was achieved with the immobilization on spent grains through multipoint covalent attachment using glycidol. This carrier showed also very good storage and operational stability (above 90%). Trypsin immobilized on spent grains showed significant activity towards whey proteins. The immobilized enzyme was slightly more stable than the free enzyme at temperatures between 50 °C and 60 °C allowing its use at a broader range of temperatures. The peptides formed with free enzyme and enzyme immobilized on spent grains were generally similar. However, significant differences existed in the amount of native proteins in the hydrolysates and in the relative amount of smaller peptides.