Structure and Function of Mung Bean Protein-Derived Iron-Binding Antioxidant Peptides

Abstract

An iron-binding mung bean protein hydrolysate (MBPH) was prepared using a continuous enzymatic membrane reactor followed by peptide separation on anion-exchange (AEC) and reverse-phase HPLC (RP-HPLC) columns. Amino acid sequences of peptides present in the RP-HPLC fraction with the strongest iron-binding capacity were identified using mass spectrometry, and ten peptides of 5–8 amino acids synthesized for antioxidant characterization. Five fractions (AF1– AF5) with higher iron-binding capacity (88.86 ± 6.43 to 153.59 ± 2.18 mg/g peptide) when compared to the MBPH (36.81 ± 0.93 mg/g peptide) were obtained from AEC. PAIDL had the significantly (p p p 50) values of 0.09 and 0.37 mM, respectively. PAIDL and AIVIL showed the lowest EC50 values of 0.07 mM each for superoxide radical scavenging activity. We conclude that short chain length in combination with leucine as the C-terminal amino acid residue contributed to the strong antioxidant properties of peptides in this study.

Keywords

• mung bean
• iron
• pancreatin
• peptides
• continuous enzymatic membrane reactor
• antioxidant