Generation, fractionation, and characterization of iron-chelating protein hydrolysate from palm kernel cake proteins

• Main Authors: Zarei, Mohammad, Ghanbari, Rahele, Tajabadi, Naser, Abdul Hamid, Azizah, Abu Bakar, Fatimah, Saari, Nazamid
• Format: Article
• Language: English
• Published: Institute of Food Technologists 2016
• Online Access: http://psasir.upm.edu.my/id/eprint/12542/1/Generation%2C%20fractionation%2C%20and%20characterization%20of%20iron-chelating%20protein%20hydrolysate%20from%20palm%20kernel%20cake%20proteins.pdf; http://psasir.upm.edu.my/id/eprint/12542/; http://onlinelibrary.wiley.com/doi/10.1111/1750-3841.13200/abstract;jsessionid=6E54B14418715A2AA500270CA2FC1FA3.f03t03

Palm kernel cake protein was hydrolyzed with different proteases namely papain, bromelain, subtilisin, flavourzyme, trypsin, chymotrypsin, and pepsin to generate different protein hydrolysates. Peptide content and iron-chelating activity of each hydrolysate were evaluated using O-phthaldialdehyde-based spectrophotometric method and ferrozine-based colorimetric assay, respectively. The results revealed a positive correlation between peptide contents and iron-chelating activities of the protein hydrolysates. Protein hydrolysate generated by papain exhibited the highest peptide content of 10.5 mM and highest iron-chelating activity of 64.8% compared with the other hydrolysates. Profiling of the papain-generated hydrolysate by reverse phase high performance liquid chromatography fractionation indicated a direct association between peptide content and iron-chelating activity in most of the fractions. Further fractionation using isoelectric focusing also revealed that protein hydrolysate with basic and neutral isoelectric point (pI) had the highest iron-chelating activity, although a few fractions in the acidic range also exhibited good metal chelating potential. After identification and synthesis of papain-generated peptides, GGIF and YLLLK showed among the highest iron-chelating activities of 56% and 53%, whereas their IC50 were 1.4 and 0.2 μM, respectively.