title: Metal-catalyzed oxidation of a structured lipid model emulsion.
abstract: The effects of temperature, time, metal, citric acid, and tocopherol contents on the oxidation stability of a model oil-in-water emulsion prepared with enzymatically synthesized menhaden oil-caprylic acid structured lipid were evaluated by response surface methodology. The emulsions were stabilized by whey protein isolate. Oxidation was monitored by measuring lipid hydroperoxides and thiobarbituric acid reactive substances (TBARS). Cupric sulfate and ferrous sulfate were used to study the effect of metal concentration and type. A statistical model was developed to determine the relationships between all variables considered. The relationships differed depending on the type of metal catalyst used. For both metal types, the metal concentration had the highest positive effect on peroxide value. Citric acid had the highest negative effect on peroxide value for iron-containing emulsions, while tocopherol had the highest negative effects for copper-containing emulsions. Results from the TBARS test did not vary significantly enough to yield an acceptable model.
authors.affiliation: Department of Food Science and Technology, The University of Georgia, Food Science Building, Athens, Georgia 30602-7610, USA.
authors.forename: Lydia B
authors.initials: LB
authors.lastname: Fomuso
authors.forename: Milena
authors.initials: M
authors.lastname: Corredig
authors.forename: Casimir C
authors.initials: CC
authors.lastname: Akoh
mesh_terms: D002210:Caprylates / Q000737:chemistry*; D002384:Catalysis; D019343:Citric Acid / Q000032:analysis / Q000494:pharmacology; D019327:Copper Sulfate / Q000737:chemistry; D004655:Emulsions / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry; D005395:Fish Oils / Q000737:chemistry*; D016014:Linear Models; D008054:Lipid Peroxides / Q000032:analysis; D008055:Lipids / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D008894:Milk Proteins; D015233:Models, Statistical; D010084:Oxidation-Reduction; D013696:Temperature; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D000067816:Whey Proteins; D024502:alpha-Tocopherol / Q000032:analysis / Q000494:pharmacology
chemical_list: D002210:Caprylates; D004655:Emulsions; D005296:Ferrous Compounds; D005395:Fish Oils; D008054:Lipid Peroxides; D008055:Lipids; D008670:Metals; D008894:Milk Proteins; D017392:Thiobarbituric Acid Reactive Substances; D000067816:Whey Proteins; C033266:Menhaden oil; D019343:Citric Acid; C020748:ferrous sulfate; D024502:alpha-Tocopherol; D019327:Copper Sulfate; C031492:octanoic acid