The Relationship between the Physicochemical Properties of Antioxidants and Their Ability to Inhibit Lipid Oxidation in Bulk Oil and Oil-in-Water Emulsions

摘要

Chain-breaking antioxidants differ in their effectiveness at inhibiting lipid oxidation because of their chemical properties and physical location within a food.Our objective was how the physicochemical properties of four structurally related lipid-soluble antioxidants were related to their antioxidant activity.Antioxidants differed in the number of methyl(alpha-tocopherol and delta-tocopherol)or hydroxyl(butylated hydroxytoluene(BHT)and 4-hydroxymethyl-2,6-ditertiarybutylphenol)groups.Surface activity of the antioxidants was in the order of delta-tocopherol > alpha-tocopherol approx= 4-hydroxymethyl-2,6-ditertiary-butylphenol > BHT.Free-radical scavenging activity was similar between a-tocopherol and delta-tocopherol as well as BHT and 4-hydroxymethyl-2,6-ditertiarybutylphenol.In bulk menhaden oil,BHT was a more effective antioxidant than 4-hydroxymethyl-2,6-ditertiarybutylphenol while alpha-tocopherol was more effective than delta-tocopherol.In menhaden oil-in-water emulsions,BHT was a more effective antioxidant than 4-hydroxymethyl-2,6-ditertiarybutylphenol while delta-tocopherol was more effective than alpha-tocopherol.These results indicate that the surface activity and polarity of lipid-soluble antioxidants were not the only determinants of their antioxidant effectiveness in food lipids.