Pigeon pea enzymatic protein hydrolysates and ultrafiltration peptide fractions as potential sources of antioxidant peptides: An in vitro study

• Published in: Food science & technology Vol. 97; pp. 269 - 278
• Main Authors: Olagunju, Aderonke I., Omoba, Olufunmilayo S., Enujiugha, Victor N., Alashi, Adeola M., Aluko, Rotimi E.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2018
• Subjects: Antioxidative peptides; Inhibition of lipid peroxidation; Membrane ultrafiltration; Pigeon pea; Antioxidative peptides; Pigeon pea; Inhibition of lipid peroxidation; Membrane ultrafiltration
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2018.07.003

Pigeon pea protein isolate was hydrolysed using food grade enzymes (alcalase, pancreatin, pepsin + pancreatin). The resulting hydrolysates were fractionated by membrane ultrafiltration and evaluated for their antioxidant activities. Fraction with molecular weight <1 kDa had the highest peptide yield (36.97%) for pepsin + pancreatin (PPHPp) hydrolysates, whereas fraction 1–3 kDa showed the highest yield (28.84%, 37.27%) for alcalase-derived peptide (PPHA) and pancreatin-derived peptide (PPHPa) respectively. Low molecular weight fractions of PPHPa showed highest inhibitory activity against DPPH•, superoxide (PPHA, PPHPa), and •OH scavenging activities. However, high molecular weight peptides exhibited better radical scavenging activity (DPPH) and reducing property (FRAP) than the low molecular weight peptides. All fractions exhibited higher ferric reducing and ABTS•+ scavenging activity than the crude hydrolysates. All the peptides also had a higher ABTS•+ scavenging activity than GSH. The low MW fractions (<5 kDa) were able to inhibit the progression of lipid peroxidation during the first four days of incubation for most of the peptides. Our findings show that membrane ultrafiltration significantly increased antioxidant properties and the peptides have the potential to be useful as functional ingredient in food and nutraceutical industry to maximise the use of underutilised protein sources. •Membrane fractionation increased bioactivity of pigeon pea protein.•Pigeon pea peptides exhibited superior radical scavenging activity and ferric reducing ability.•Low molecular weight peptides exhibited superior ability to inhibit lipid peroxidation.•Peptides have potential for use as functional ingredient in nutraceuticals.