Antioxidant and enzymes inhibitory properties of Amaranth leaf protein hydrolyzates and ultrafiltration peptide fractions. Issue 3 (21st July 2020)

• Record Type: Journal Article
• Authors: Famuwagun, Akinsola A.; Alashi, Adeola M.; Gbadamosi, Olasunkanmi S.; Taiwo, Kehinde A.; Oyedele, Durodoluwa; Adebooye, Odunayo C.; Aluko, Rotimi E.
• Is Part Of: Journal of food biochemistry. Volume 45:Issue 3(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-07-21
• Subjects: ACE inhibition -- antioxidant properties -- leaf protein hydrolyzate -- α‐amylase -- α‐glucosidase; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; Biochemistry -- Periodicals; 664.024
• DOI: 10.1111/jfbc.13396
• Languages: English
• ISSNs: 0145-8884

Abstract

Abstract: Amaranth leaf protein isolate (ALI) was hydrolyzed using four different proteases (alcalase, trypsin, pepsin, and chymotrypsin) followed by fractionation of the pepsin hydrolyzate (PH) into different sizes using ultrafiltration membrane. Gel permeation chromatography showed that all the hydrolyzates had smaller size peptides (<7 kDa) than the protein isolate (>32 kDa). The chymotrypsin hydrolyzate had higher contents of hydrophobic amino acid (44.95%) compared to alcalase (42.72%), pepsin (43.93%), and trypsin (40.95%) hydrolyzates. The PH had stronger DPPH, hydroxyl radical, and superoxide radical scavenging activities than the other protein hydrolyzates but weaker Ferric reducing antioxidant power and metal chelating activities when compared to the peptide fractions. The <1 kDa peptide fraction exhibited stronger DPPH, hydroxyl, and superoxide radicals scavenging activities than the higher molecular weight (>1 kDa) fractions. Fractionation of PH also resulted in enhanced inhibition of α‐amylase and ACE activities but weaker α‐glucosidase inhibition. Practical applications: ALI was hydrolyzed using four proteases to produce protein hydrolyzates. The most active of the hydrolyzate was then fractionated to produce fractions of different molecular sizes. The results of the analyses showed that the hydrolyzates and the fractions showed good antioxidant and enzyme inhibitory activities such as the inhibition of ACE, α‐amylase, and glucosidase enzymes. The results suggest that the enzymatic hydrolyzates and peptide fractions could be used as ingredients in the nutraceutical and functional food industries to scavenge free radicals and inhibit angiotensin‐converting enzyme activity. Abstract : The amaranth leaf protein hydrolyzates had smaller size peptides than its protein isolate. PH had strong radical scavenging activities but weak FRAP and metal chelating activities when compared to other protein hydrolyzates. The <1 kDa peptide fraction exhibited stronger free radical scavenging activities than >1 kDa fractions. Fractionation of PH also resulted in enhanced inhibition of α‐amylase and ACE activities but weaker α‐glucosidase inhibition. The amaranth leaf hydrolyzates and the separated fractions demonstrated potentials as functional ingredients