Relationship between antioxidant capacity and angiotensin-converting enzyme inhibitory activity of papain-generated protein hydrolysates and peptides from palm kernel cake proteins

• Main Authors: Zarei, Mohammad, Abdul Hamid, Azizah, Hasan, Belal J. Muhialdin Mula, Saari, Nazamid
• Format: Article
• Language: English
• Published: Faculty of Food Science and Technology, Universiti Putra Malaysia 2019
• Online Access: http://psasir.upm.edu.my/id/eprint/76420/1/25.pdf; http://psasir.upm.edu.my/id/eprint/76420/; http://www.ifrj.upm.edu.my/26%20(05)%202019/25.pdf
• Institution: Universiti Putra Malaysia

Palm kernel cake (PKC) proteins were hydrolysed in the presence of seven proteolytic enzymes. The antioxidant and antihypertensive activities of each protein hydrolysate were evaluated. Papain-generated protein hydrolysate showed the highest antioxidant effects measured by radical scavenging activity (65%), iron (Fe)(II)-chelating activity (65%), and antihypertensive activity (71%). The results revealed a strong correlation between the antioxidant activity of the protein hydrolysates with angiotensin-converting enzyme (ACE) inhibitory activity (R2 = 0.69 - 0.98), except for trypsin-generated hydrolysate (R2= 0.22). The most potent protein hydrolysate was fractionated and profiled using reversed-phase high-performance liquid chromatography and isoelectric focusing; peptides were subsequently isolated and identified by tandem mass spectrometry. The individual peptides were evaluated for antihypertension potential. A positive correlation was identified between radical scavenging activity and Fe(II)-chelating activity together and ACE inhibitory activity with R2 = 0.69 - 0.98. The findings indicate that there was a positive relationship between the antioxidant and antihypertensive activities of protein hydrolysates and bioactive peptides from PKC proteins.