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A Physicochemical Study of the Effects of Acidity on the Distribution and Antioxidant Efficiency of Trolox in Olive Oil‐in‐Water Emulsions
Author(s) -
Galan Anna,
LosadaBarreiro Sonia,
BravoDíaz Carlos
Publication year - 2016
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201500882
Subject(s) - trolox , chemistry , emulsion , pulmonary surfactant , antioxidant , organic chemistry , inorganic chemistry , chemical engineering , chromatography , antioxidant capacity , biochemistry , engineering
The efficiency of antioxidants to inhibit the oxidation of lipid‐based emulsions depends on several factors including their nature and their concentration at the reaction site. Here, we have analyzed the effects of acidity and of surfactant concentration on the distribution and efficiency of the vitamin E analog Trolox (TR) in stripped olive oil‐in‐water emulsions stabilized with Tween 20. The distribution was assessed in the intact emulsions by employing a kinetic method that exploits the reaction between the hydrophobic 4‐hexadecylbenzenediazonium ions and TR. Kinetic results are interpreted on the grounds of the pseudophase model. The effects of TR on the oxidative stability of the emulsion were determined at different pH values by monitoring the formation of conjugated dienes over time. The results show that the efficiency of TR increases upon increasing pH even though its concentration in the interfacial region decreases.