Tag: antioxidant efficiency

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

Posted on by 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. [...]

Physical evidence that the variations in the efficiency of homologous series of antioxidants in emulsions are due to differences in their partitioning

Posted on by antiox@uvigo.es

The relationships between the hydrophilic-lipophilic balance (HLB) of antioxidants (AOs) and their distributions and efficiencies in emulsions are not fully understood. Recent reports indicate that, for series of homologous antioxidants of different hydrophobicity, the variation of their efficiency with the HLB of the AO increases with the alkyl chain length up to a maximum (C3 -C8ester) followed by a decrease [...]

Optimizing the efficiency of antioxidants in emulsions by lipophilization:tuning interfacial concentrations

Posted on by antiox@uvigo.es

Optimization of the efficiency of antioxidants, AOs, in lipid-based emulsions via chemical modifications of their reactive moieties is not always possible because of the inherent experimental difficulties and because of the regulatory status of AOs. Esterification of hydrophilic AOs may be a practical, convenient, alternative approach [...]

Interfacial Concentrations of Hydroxytyrosol and its Lipophilic Esters in Intact Olive Oil-in-Water Emulsions. Effects of Antioxidant Hydrophobicity, Surfactant Concentration and the Oil to Water Ratio on the Oxidative Stability of the Emulsions

Posted on by antiox@uvigo.es

We determined the interfacial molarities of the antioxidants, AOs, hydroxytyrosol (HT), and HT fatty acid esters with chain lengths of 1 to 16 carbons in intact olive oil/water/Tween 20 emulsions. The results were compared with chain length effects on the oxidative stability of the same emulsions, and a direct correlation was established [...]

Maxima in antioxidant distributions and efficiencies with increasing hydrophobicity of gallic acid and its alkyl esters. The pseudophase model interpretation of the “cutoff effect”

Posted on by antiox@uvigo.es

Antioxidant (AO) efficiencies are reported to go through maxima with increasing chain length (hydrophobicity) in emulsions. The so-called “cutoff” after the maxima, indicating a decrease in efficiency, remains unexplained. This paper shows, for gallic acid (GA) and propyl, octyl, and lauryl gallates (PG, OG, and LG, respectively) [...]

Distribution of Hydroxytyrosol and Hydroxytyrosol Acetate in Olive Oil Emulsions and Their Antioxidant Efficiency

Posted on by antiox@uvigo.es

We employed a kinetic method to determine the distributions of the antioxidants hydroxytyrosol (HT) and hydroxytyrosol acetate (HTA) between the oil, aqueous, and interfacial regions of a model food emulsion composed of stripped olive oil, acidic water, and a blend of Tween 80 and Span 80 [hydrophilic–lipophilic balance (HLB) = 8.05] as an emulsifier [...]