Jr. Mancuso et al., The effects of surfactant type, pH, and chelators on the oxidation of salmon oil-in-water emulsions, J AGR FOOD, 47(10), 1999, pp. 4112-4116
Lipid oxidation in emulsions is influenced by the ability of transition met
als to associate with emulsion droplets. The oxidative stability of 5% salm
on oil-in-water emulsion was influenced by surfactant type, with oxidation
rates being greatest in emulsions stabilized by anionic sodium dodecyl sulf
ate (SDS) followed by nonionic Tween 20 and cationic dodecyltrimethylammoni
um bromide (DTAB). EDTA inhibited lipid oxidation in all the emulsions, and
apo-transferrin inhibited oxidation in the Tween 20-stabilized emulsions a
t pH 7.0, suggesting that continuous-phase iron was an active prooxidant. I
ron associated with Tween-20 stabilized hexadecane emulsion droplets could
be partitioned into the continuous phase by lowering the pH to less than or
equal to 4.0 or by the presence of EDTA, which could help explain why low
pH and EDTA decrease lipid oxidation rates. These data suggest that iron is
an important lipid oxidation catalyst in salmon oil emulsions, and factors
that; increase iron-emulsion droplet interactions will increase oxidation
rates.