title: Role of carbohydrases on the release of reducing sugar, total phenolics and on antioxidant properties of oat bran.
abstract: Aqueous solutions of medium oat bran flour were treated with four carbohydrases viscozyme, celluclast, alpha-amylase, and amyloglucosidase, and then extracted with equal volume of methanol. The resulting extracts were examined for their reducing sugar content, total phenolic content (TPC), oxygen radical scavenging absorbance capacity (ORAC), hydroxyl radical scavenging effect, superoxide scavenging activity, and ferrous ion chelating potential. The amount of reducing sugar increased form 2.0% in the control sample to 21.4% in the sample treated with four fungal beta-glucanase units/g of bran. The increase in reducing sugar was also associated with subsequent increase of other extractable compounds. The total phenolic content as measured by Folin-Ciocalteu's method ranged from 0.50 to 4.80mg of gallic acid equivalents/g of bran, whereas the ORAC values were 14.4-25.4μM of Trolox equivalents/g of bran. All the samples treated with carbohydrases had higher TPC content and higher ORAC values than the control sample (no enzyme treatment). In the hydroxyl radical scavenging assay, except for the alpha-amylase treated sample, all other samples demonstrated a greater inhibition power than the control. These results indicated that pre-treatment of oat bran with cell wall degrading enzymes (i.e. carbohydrases) is a way to increase the amount of extracted phenols as well as the antioxidant properties of oat bran samples.
authors.affiliation: Food Science and Nutrition Program, Chemistry Department, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6.
authors.forename: Roaaya
authors.initials: R
authors.lastname: Alrahmany
authors.affiliation: Food Science and Nutrition Program, Chemistry Department, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6. Electronic address: apollinaire_tsopmo@carleton.ca.
authors.forename: Apollinaire
authors.initials: A
authors.lastname: Tsopmo
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D018554:Avena / Q000378:metabolism*; D002241:Carbohydrates / Q000032:analysis*; D002473:Cell Wall / Q000378:metabolism; D016166:Free Radical Scavengers / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D006026:Glycoside Hydrolases / Q000378:metabolism*; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry; D012639:Seeds / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002241:Carbohydrates; D016166:Free Radical Scavengers; D005609:Free Radicals; D010636:Phenols; D010936:Plant Extracts; D006026:Glycoside Hydrolases; C019822:carbohydrase
keywords: Antioxidant; Carbohydrase; Oat bran; Phenols