Interfacial Concentrations of Hydroxytyrosol Derivatives in Fish Oil-in-Water Emulsions and Nanoemulsions and Its Influence on Their Lipid Oxidation: Droplet Size Effects

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Costa, M (Author) Other; Losada Barreiro, S (Author) Other; Bravo Diaz, C (Author) Other; Monteiro, LS (Author) Other; Fatima Paiva Martins (Author) FCUP

Journal

Title: Foods

Vol. 1863

Final page: 1897

Publisher: MDPI

Indexing

ISI Web of Knowledge - 5 Citations

Other information

Authenticus ID: P-00T-B65

DOI: 10.3390/foods9121897

Abstract (EN): Reports on the effect of droplet size on the oxidative stability of emulsions and nanoemulsions are scarce in the literature and frequently contradictory. Here, we have employed a set of hydroxytyrosol (HT) esters of different hydrophobicity and fish oil-in-water emulsified systems containing droplets of different sizes to evaluate the effect of the droplet size, surfactant, (phi(I)) and oil (phi(O)) volume fractions on their oxidative stability. To quantitatively unravel the observed findings, we employed a well-established pseudophase kinetic model to determine the distribution and interfacial concentrations of the antioxidants (AOs) in the intact emulsions and nanoemulsions. Results show that there is a direct correlation between antioxidant efficiency and the concentration of the AOs in the interfacial region, which is much higher (20-200 fold) than the stoichiometric one. In both emulsified systems, the highest interfacial concentration and the highest antioxidant efficiency was found for hydroxytyrosol octanoate. Results clearly show that the principal parameter controlling the partitioning of antioxidants is the surfactant volume fraction, phi(I), followed by the O/W ratio; meanwhile, the droplet size has no influence on their interfacial concentrations and, therefore, on their antioxidant efficiency. Moreover, no correlation was seen between droplet size and oxidative stability of both emulsions and nanoemulsions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 16