Membrane filtration is considered to be a low-cost and large scale method for recovery and purification of enzymes. The trypsin-like serine protease (TSP) was recovered and purified by microfiltration and ultrafiltration from the extract of the spleen of the yellowfin tuna (Thunnus albacores). The partially purified TSP has the activity of 96.5 U/mL and purity of 74.2 U/mg protein based on casein digesting unit. It has the molecular weight of 24 kDa proved by SDS-PAGE. The potential application of TSP in the protein hydrolysis was investigated in comparison to the use of two commercial proteases, i.e. Alcalase® 0.6 L and Delvo-Pro under their optimal hydrolysis conditions. The effects of enzymes, substrates and enzyme to substrate ratio on the degree of hydrolysis (DH) were studied. Alcalase showed the highest DH for both casein and soybean isolate. TSP showed higher DH than Delvo-Pro when casein was employed as the substrate. However, TSP showed the lowest DH when soybean protein was used as the substrate. The present study proved that TSP recovered and purified from the tuna canning waste by membrane filtration can be used for protein hydrolysis as well as other commercial proteases.
Bibliographical noteFunding Information:
The authors gratefully acknowledge Faculty of Agro-Industry and Graduate School, Prince of Songkla University for financial support of the work. The authors also express their gratitude to Chotiwat Manufacturing Co. Ltd. for providing yellowfin tuna viscera and Songkhla Canning Public Co Ltd (Thailand) for providing Delvo-Pro used in this study.
- Membrane filtration
- Protein hydrolysis
- Tuna spleen
ASJC Scopus subject areas
- Food Science