title: Comparison of antioxidant capacity, protein profile and carbohydrate content of whey protein fractions.
abstract: Whey is used as an additive in food industry and a dietary supplement in nutrition. Here we report a comparative analysis of antioxidant potential of whey and its fractions. Fractions were obtained by size exclusion chromatography, before and after enzymatic digestion with pepsin or trypsin. Superoxide radical scavenging, lipid peroxidation inhibition and cupric ion reducing activities of different fractions were checked. Peptides were detected by SDS-PAGE and GC-MS was used to determine carbohydrate content of the fractions. All samples showed antioxidant activity and the second fraction of the trypsin hydrolysate showed the highest superoxide radical scavenging activity. CUPRAC value of this fraction was two-times higher than that of whey filtrate. The first fraction of the pepsin hydrolysate was the most effective inhibitor of lipid peroxidation. Each sample exhibited a different polypeptide profile. Different percentages of carbohydrates were identified in whey filtrate and in all second fractions, where galactose was the major component.
authors.affiliation: Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, 34134 Vezneciler-Istanbul, Turkey.
authors.forename: Evren
authors.initials: E
authors.lastname: Önay-Uçar
authors.affiliation: Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, 34134 Vezneciler-Istanbul, Turkey.
authors.forename: Nazlı
authors.initials: N
authors.lastname: Arda
authors.affiliation: Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, 34134 Vezneciler-Istanbul, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Pekmez
authors.affiliation: Department of Biochemistry, School of Medicine, Marmara University, 34668 Haydarpaşa-Istanbul, Turkey.
authors.forename: Ayşe Mine
authors.initials: AM
authors.lastname: Yılmaz
authors.affiliation: Section of Organic Chemistry, Department of Chemistry, Faculty of Science, Ege University, 35500 Bornova-Izmir, Turkey.
authors.forename: Nazlı
authors.initials: N
authors.lastname: Böke-Sarıkahya
authors.affiliation: Section of Organic Chemistry, Department of Chemistry, Faculty of Science, Ege University, 35500 Bornova-Izmir, Turkey.
authors.forename: Süheyla
authors.initials: S
authors.lastname: Kırmızıgül
authors.affiliation: Department of Biochemistry, School of Medicine, Marmara University, 34668 Haydarpaşa-Istanbul, Turkey. Electronic address: asyalcin@marmara.edu.tr.
authors.forename: A Suha
authors.initials: AS
authors.lastname: Yalçın
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D002241:Carbohydrates / Q000737:chemistry*; D006868:Hydrolysis; D015227:Lipid Peroxidation; D008894:Milk Proteins / Q000737:chemistry*; D010084:Oxidation-Reduction; D010940:Plant Proteins / Q000737:chemistry*; D014357:Trypsin / Q000737:chemistry; D000067816:Whey Proteins
chemical_list: D000975:Antioxidants; D002241:Carbohydrates; D008894:Milk Proteins; D010940:Plant Proteins; D000067816:Whey Proteins; D014357:Trypsin
keywords: Antioxidant activity; CUPRAC; Whey protein fractions