title: Fractionation, separation, and identification of antioxidative peptides in potato protein hydrolysate that enhance oxidative stability of soybean oil emulsions.
abstract: The objective of the study was to identify the active peptides responsible for the antioxidant activity of potato protein hydrolysate (PPH). PPH was fractionated using ammonium sulfate precipitation; the efficacy of different fractions for scavenging 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+•)) radicals and inhibiting lipid oxidation (hexanal, TBARS) in soybean oil-in-water emulsions was investigated. Of all fractions, the fraction precipitated by 50% saturated ammonium sulfate (P50) exhibited the strongest ABTS(+•) scavenging activity and antioxidant activity. Active peptides based on the ABTS(+•) scavenging assay were isolated and purified by RP-HPLC and ultra performance liquid chromatography. Amino acid sequencing by tandem mass spectrometry identified Ser-Ser-Glu-Phe-Thr-Tyr and Ile-Tyr-Leu-Gly-Gln in P50 to be the dominant peptides that matched the sequences in metallocarboxypeptidase inhibitor and lipoxygenase 1, respectively.
authors.affiliation: State Key Lab. of Food Science and Technology, and School of Food Science and Technology, Jiangnan Univ., Wuxi, Jiangsu 214122, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cheng
authors.forename: Youling L
authors.initials: YL
authors.lastname: Xiong
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
mesh_terms: D000645:Ammonium Sulfate / Q000378:metabolism; D000975:Antioxidants / Q000032:analysis* / Q000302:isolation & purification; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid; D004655:Emulsions / Q000737:chemistry; D008084:Lipoxygenase / Q000737:chemistry / Q000378:metabolism; D018384:Oxidative Stress; D010446:Peptide Fragments / Q000032:analysis* / Q000302:isolation & purification; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D011480:Protease Inhibitors; D011492:Protein Hydrolysates / Q000032:analysis*; D011198:Solanum tuberosum / Q000737:chemistry*; D013024:Soybean Oil / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D000975:Antioxidants; D004655:Emulsions; D010446:Peptide Fragments; D010940:Plant Proteins; D011480:Protease Inhibitors; D011492:Protein Hydrolysates; D013024:Soybean Oil; D008084:Lipoxygenase; D000645:Ammonium Sulfate