title: Enzyme-assisted extraction and identification of antioxidative and α-amylase inhibitory peptides from Pinto beans (Phaseolus vulgaris cv. Pinto).
abstract: Antioxidant and α-amylase inhibitor peptides were successfully extracted from Pinto bean protein isolate (PBPI) using Protamex. A factorial design experiment was conducted and the effects of extraction time, pH and temperature were studied. pH 7.5, extraction time of 1h, S/E ratio of 10 (w/w) and temperature of 50 °C gave the highest antioxidant activities (i.e., ABTS scavenging activity (53.3%) and FRAP value (3.71 mM)), whereas pH 6.5 with the same extraction time, S/E ratio and temperature, gave the highest α-amylase inhibitory activity (57.5%). It was then fractioned using membrane ultrafiltration with molecular weight cutoffs of 100, 50, 30, 10 and 3 kDa. Peptide fraction <3 kDa, which exhibited the highest antioxidant activities (i.e., ABTS (42.2%) and FRAP (0.81 mM)) and α-amylase inhibitory activity (62.1%), was then subjected to LCMS and MS/MS analyses. Six sequences were identified for antioxidant peptides, whereas seven peptides for α-amylase inhibitor.
authors.affiliation: Centre for Advanced Analytical Toxicology Services, Universiti Sains Malaysia (USM), 11800 Penang, Malaysia.
authors.forename: Ying-Yuan
authors.initials: YY
authors.lastname: Ngoh
authors.affiliation: Centre for Advanced Analytical Toxicology Services, Universiti Sains Malaysia (USM), 11800 Penang, Malaysia. Electronic address: mattgan81@yahoo.com.
authors.forename: Chee-Yuen
authors.initials: CY
authors.lastname: Gan
mesh_terms: D000595:Amino Acid Sequence; D000975:Antioxidants / Q000302:isolation & purification*; D005591:Chemical Fractionation; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010455:Peptides / Q000302:isolation & purification* / Q000378:metabolism; D027805:Phaseolus / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D013696:Temperature; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
chemical_list: D000975:Antioxidants; D010455:Peptides; D000516:alpha-Amylases
keywords: Antioxidative; Bioactive peptides; Pinto bean; α-Amylase inhibitor