title: Antioxidant capacity of flaxseed products: the effect of in vitro digestion.
abstract: This study evaluated the effect of in vitro digestion of flaxseed products on Folin-Ciocalteu reagent reducing substances (FCRRS), its antioxidant capacity and prevention of oxidative DNA damage in human monocyte cell line U937. Flaxseed protein isolate was obtained from defatted flaxseed meal and the protein hydrolysate with high antioxidant capacity was obtained from hydrolysis of the protein isolate with Alcalase in a two factor central composite rotatable design (pH 8.5 and enzyme: substrate 1:90, w/w). The FCRRS content and antioxidant capacity measured by FRAP and ORAC in aqueous and 70 % methanol extracts were the highest in protein hydrolysate, followed by protein isolate, while the defatted meal showed the lowest values. After in vitro gastrointestinal digestion, the FCRRS content of protein isolate and hydrolysate reached similar values, however the hydrolysate had the highest antioxidant capacity, measured by FRAP while the isolate had the highest ORAC values. The defatted meal showed the lowest capacity in all assays (p < 0.05). The hydrolysate did not protect against DNA damage induced by H2O2 in U937 cells under the conditions of the present study. The results suggest that flaxseed protein isolate and hydrolysate are potential functional food ingredients with antioxidant capacity.
authors.affiliation: Department of Food and Nutrition, Faculty of Food Engineering, University of Campinas - Unicamp, R. Monteiro Lobato, 80, PO Box 6121, Campinas, SP, Brazil, 13083-862.
authors.forename: F G D
authors.initials: FG
authors.lastname: Silva
authors.forename: Y
authors.initials: Y
authors.lastname: O'Callagahan
authors.forename: N M
authors.initials: NM
authors.lastname: O'Brien
authors.forename: F M
authors.initials: FM
authors.lastname: Netto
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002460:Cell Line; D004249:DNA Damage / Q000187:drug effects*; D004044:Dietary Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D004063:Digestion; D019597:Flax / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000494:pharmacology; D055951:Functional Food; D006801:Humans; D006861:Hydrogen Peroxide; D009000:Monocytes / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D028321:Plant Preparations / Q000494:pharmacology; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology; D011492:Protein Hydrolysates / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D004044:Dietary Proteins; D016166:Free Radical Scavengers; D010936:Plant Extracts; D028321:Plant Preparations; D010940:Plant Proteins; D011492:Protein Hydrolysates; D006861:Hydrogen Peroxide