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Control of antioxidant efficiency of chlorogenates in emulsions: modulation of antioxidant interfacial concentrations
Author(s) -
Meireles Mafalda,
LosadaBarreiro Sonia,
Costa Marlene,
PaivaMartins Fátima,
BravoDíaz Carlos,
Monteiro Luís S
Publication year - 2019
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.9615
Subject(s) - emulsion , chemistry , antioxidant , molar concentration , partition coefficient , stoichiometry , homologous series , chemical engineering , molar ratio , oil droplet , chemical composition , water in oil , chromatography , organic chemistry , catalysis , engineering
BACKGROUND Controlling the interfacial concentrations of antioxidants (AOs) in oil‐in‐water emulsions can be regarded as a unique approach for increasing the efficiency of AOs in inhibiting the oxidation of lipids. Classical methods to determine the AO distribution in binary systems cannot be employed and their distribution needs to be assessed in the intact emulsion. RESULTS We have employed a well‐established kinetic method to determine the distribution of a homologous series of AOs derived of chlorogenic acid in olive oil‐in‐water emulsions and analyse the effects of AO hydrophobicity on their distributions and their efficiencies. Results indicate that variations in the efficiency of chlorogenates in emulsions are due to differences in their interfacial concentrations. Their interfacial concentrations AO I were much higher (20‐ to 150‐fold) than their stoichiometric concentrations. On the other hand, their concentrations in the oil region were 1.5‐ to 0.1‐fold. Results also show the complex effect of the oil‐to‐water ratio employed in the preparation of the emulsions on the (AO I ) values. CONCLUSION Results highlight the key role of the interfacial region and of its composition (interfacial AO molarity, emulsifier concentration, oil‐to‐water ratio) in interpreting the efficiency of AOs in inhibiting lipid oxidation in emulsions. Thus, a careful modulation of these parameters is necessary to ensure optimum AO efficiency. © 2019 Society of Chemical Industry