Categoría: Publicaciones del 2018

The location of amphiphobic antioxidants in micellar systems: the diving-swan analogy

Publicada en por antiox@uvigo.es

The location of antioxidants (AOs) in a micellar system was determined with the aid of a recently described protocol. The protocol was applied to trolox, caffeic, and gallic acid derivatives of increasing hydrophobicities. The amphiphobic nature of the AOs determined their insertion and orientation in the micellar interface. Their behaviour in a hetero-phasic system was rationalized with a pictorial simile, the “diving-swan” analogy. [...]

Differential partitioning of lipophilic bioantioxidants in edible oil-water and octanol-water

Publicada en por antiox@uvigo.es

Partition coefficients, PWO, of antioxidants (AOs) between edible oils and water are scarce in the literature, despite that AOs are widely used to control lipid oxidation and the oxidative stress in cells. PWO values have a great importance to predict the efficiency and distribution of bioactives at different levels of biological organization from binary oil–water systems to living cells [...]

Enhancement of the antioxidant efficiency of gallic acid derivatives in intact fish oil-in-water emulsions throught optimization of their interfacial concentrations

Publicada en por antiox@uvigo.es

The antioxidant (AO) efficiencies and the distributions of gallic acid (GA) and a series of alkyl gallates (propyl, PG, butyl, BG, octyl, OG and lauryl, LG) were determined in intact fish oil-in-water emulsions. The efficiency of the AOs in inhibiting the oxidation of the fish oil lipids increases upon increasing AO hydrophobicity up to a maximum (∼3-fold) at the octyl derivative, after which the efficiency decreases (LG) [...]

Modulating the interfacial concentration of gallates to improve the oxidative stability of fish oil-in-water emulsions

Publicada en por antiox@uvigo.es

The distributions of some gallates were determined in intact fish oil emulsions. % gallates at the interface increases upon increasing surfactant volume fraction ΦI. On the contrary, their interfacial concentrations decrease upon increasing ΦI. Their efficiencies correlate directly with the gallate interfacial concentrations. Butyl and octyl gallates were the most suitable to protect the fish emulsions. [...]

Partitioning of aryl radicals in micellar systems

Publicada en por antiox@uvigo.es

Determining the association constants of radicals to biomimetic systems is not a simple task because of the inherent experimental difficulties associated to their “in‐situ” generation together with their high chemical instability, requiring the use of radical trapping agents in combination with, for example, magnetic (eg, EPR) and/or time‐resolved techniques (eg, frequency comb spectroscopy) to indentify and quantify them. Here, we have exploited the unique electrochemical properties of arenediazonium ions, ArN2+, to estimate the association constant of the electrochemically generated aryl radicals derived from benzenediazonium ions, BD, with sodium dodecyl sulfate (SDS) micelles [...]