| Summary: | 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 (<i>p</i> < 0.05) highest iron-binding capacity, but LLLLG and LLGIL showed the strongest metal chelating activity. However, PAIDL (46.63%) and LLGIL (81.27%) had significantly (<i>p</i> < 0.05) better DPPH radical scavenging activity than the other peptides. PAIDL and LLGIL were also the most effective (<i>p</i> < 0.05) hydroxyl radical neutralizers with an effective concentration that scavenged 50% (EC<sub>50</sub>) values of 0.09 and 0.37 mM, respectively. PAIDL and AIVIL showed the lowest EC<sub>50</sub> values of 0.07 mM each for superoxide radical scavenging activity. We conclude that short chain length in combination with leucine as the <i>C</i>-terminal amino acid residue contributed to the strong antioxidant properties of peptides in this study.
|
|---|