title: Isolation and identification of antioxidant peptides from enzymatically hydrolyzed rice bran protein.
abstract: Khao Dawk Mali 105 rice bran protein (RBP) was fractionated into albumin (12.5%), globulin (13.9%), glutelin (70.8%) and prolamine (2.9%). The native and denatured RBP fractions were hydrolyzed with papain and trypsin for 3h at optimum conditions. The RBP fractions and their hydrolysates were evaluated for their antioxidant activity by the Oxygen Radical Absorbance Capacity (ORAC) assay. The trypsin-hydrolyzed denatured albumin exhibited the highest antioxidant activity with an ORAC value of 4.07 μmol of Trolox equivalent (TE)/mg protein. This hydrolysate was separated by using RP-HPLC and three fractions with high antioxidant activity were examined by LTQ-FTICR ESI mass spectrometry. The MW of the peptides from these fractions were 800-2100 Da. and consisted of 6-21 amino acid residues. Most of the peptides from the fractions demonstrated typical characteristics of well-known antioxidant peptides. The results suggest that trypsin-hydrolyzed denatured rice bran albumin might be useful as a natural food antioxidant.
authors: Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok 10900, Thailand.
authors: Ladda
authors: L
authors: Wattanasiritham
authors: Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok 10900, Thailand. Electronic address: fagicct@ku.ac.th.
authors: Chockchai
authors: C
authors: Theerakulkait
authors: Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA.
authors: Samanthi
authors: S
authors: Wickramasekara
authors: Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA.
authors: Claudia S
authors: CS
authors: Maier
authors: Department of Pharmaceutical Sciences, College of Pharmacy and the Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA.
authors: Jan F
authors: JF
authors: Stevens
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D006868:Hydrolysis; D012275:Oryza / Q000737:chemistry*; D010084:Oxidation-Reduction; D010455:Peptides / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D011492:Protein Hydrolysates / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D014357:Trypsin / Q000378:metabolism
chemical_list: D000975:Antioxidants; D010455:Peptides; D010936:Plant Extracts; D010940:Plant Proteins; D011492:Protein Hydrolysates; D014357:Trypsin
keywords: Antioxidant peptides; Enzymatic hydrolysates; Rice bran protein