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

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

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 [...]

kinetics and mechanism of the reaction between 3-methylbenzenediazonium ions and catechol

We have investigated the kinetics and mechanism of the reaction between 3-methylbenzenediazonium, 3MBD, ions and catechol (1,2-dihydroxybenzene, [CAT]) in aqueous buffer solution under acidic conditions by employing spectrometric UV/VIS. The variation of the observed rate constant, kobs, with the acidity at a given [CAT] follows an upward curve [...]

A physicochemical study of the effects of acidity on the distribution and antioxidant efficiency of Trolox in olive-oil in water emulsions

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 [...]