Modeling chemical reactivity in emulsions

Interfacial kinetics in octane based emulsions. Effects of surfactant concentration on the reaction between 16-ArN2+ and octyl and lauryl gallates

“…Here we have expanded our previous investigations to systems where reactants, here 16 e.g., the reaction site between the antioxidant and the lipid radicals [22,24,26]. The lipid oxidation reaction is a radical reaction that needs to be controlled and minimized in as much as possible because it degrades the foods quality by diminishing their organoleptic properties and producing undesired off-flavors and harmful products [26].…”

“…When k chem k dif , the dynamic equilibrium condition applies and the effects of aggregates on chemical reactivity can be interpreted in terms of pseudophase models, which consider that reactants distribute between oil, aqueous and interfacial regions of the droplets thermodynamically according to their solubilities in each region and where they can react, Scheme 1 [1,16]. Under these conditions, the observed rate of the reaction r is the sum of the rates in each region, Eq.…”

“…During the last years, we have exploited the reaction between a hydrophobic arenediazonium salt, 4-hexadecylbenzenediazonium, 16-ArN 2 + , tetrafluoroborate, with antioxidants (AOs) to assess their distribution in neutral and ionic emulsions [16,[22][23][24][25]. We have successfully applied our methodology to determine the partition constants and the distributions of very hydrophilic (i.e., oil insoluble) antioxidants such as phenolic acids and ascorbic acid (Vitamin C), very hydrophobic (i.e., water insoluble) antioxidants such as atocopherol, lauryl gallate or hexadecyl caffeate, and antioxidants of moderate hydrophobicity which are both oil and water soluble such as propyl gallate and catechol.…”

“…Colloidal systems are dynamic in nature and the mechanisms of transfer of reactants between aggregates and the nature of the collision processes (e.g., rate of coalescence of droplets) need also to be considered because they may be of significance to the reaction kinetics. Several reviews on the formation, structure dynamics and potential uses as microreactors of association colloids are available in the literature [6,[13][14][15][16][17].…”

Rheological reversibility and long-term stability of repulsive and attractive nanoemulsion gels

“…50 Therefore diffusion of oxidized products into micelles and their and distribution would be much faster compared to the rate of lipid oxidation. 51 It may also promote the transfer of hydroperoxides from one droplet to another by micelles leading to enhanced lipid oxidation in the droplets. 37 In fact, evidence of higher lipid oxidation in attractive nanogels (TOTOX ¼ 30-38 in the oil separated from the 15 CMC nanogels aer 90 days of storage at room temperature) was seen.…”