REQUIMTE-LAQV, Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Porto, Portugal.
Department of Physical Chemistry, Faculty of Chemistry, University of Vigo, Vigo, Spain.
J Sci Food Agric. 2019 Jun;99(8):3917-3925. doi: 10.1002/jsfa.9615. Epub 2019 Mar 1.
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.
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 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 ) values.
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.
控制油包水乳状液中抗氧化剂 (AO) 的界面浓度可被视为提高 AO 抑制脂质氧化效率的独特方法。经典方法无法用于测定二元体系中 AO 的分布，需要在完整乳液中评估其分布。
我们采用了一种成熟的动力学方法来测定源于绿原酸的一系列 AO 在橄榄油包水乳状液中的分布，并分析 AO 疏水性对其分布和效率的影响。结果表明，绿原酸盐在乳液中的效率变化归因于其界面浓度的差异。其界面 AO 浓度比其化学计量浓度高 20-150 倍。另一方面，其在油区的浓度为 1.5-0.1 倍。结果还表明在制备乳液时所采用的油水比的复杂影响对 (AO) 值的影响。
结果突出了界面区域及其组成（界面 AO 摩尔浓度、乳化剂浓度、油/水比）在解释 AO 抑制乳液中脂质氧化效率方面的关键作用。因此，需要仔细调节这些参数以确保 AO 效率最佳。© 2019 英国化学工业协会。
