Chia Oil-in-Water Nanoemulsions Produced by Microfluidization

CENSI, NICOLÁS; JULIO, LUCIANA M.; TOMÁS, MABEL C.

La Plata y San Salvador de Jujuy

Conferencia; IV Conference Ia ValSe-Food CYTED and VII Symposium Chia-Link; 2022

ValSe-Food CYTED

Oil-in-water (O/W) nanoemulsions (d < 200 nm) are systems with considerable potential for protecting and delivering sensible ingredients such as chia seed oil rich in ω-3 fatty acids (~64% α-linolenic acid). These systems can be formed by applying either low- or high-energy methods. High-pressure homogenization, microfluidization and sonication are included within the latter. The main aim of this research work was to obtain and characterize chia oil-in-water nanoemulsions by microfluidization. Therefore, O/W nanoemulsions with 10% (w/w) chia oil and 2% (w/w) sodium caseinate were prepared at three levels of microfluidization pressure: 600, 1000 and, 1200 bar. Droplet sizes of the nanoemulsions expressed as the Sauter mean diameter, were found between 108 to 125 nm. Additionally, the resulting superficial droplet charge was between −37 to −41 mV. The global stability of the different systems was evaluated through the evolution of their backscattering for 50 days. In this sense, nanoemulsions obtained at 1000 and 1200 bar recorded high global stability, while those obtained at 600 bar showed some signs of destabilization. In terms of oxidative stability, all systems studied recorded low values of primary and secondary oxidation products as a function of storage, as determined by peroxide value index (PV) and thiobarbituric acid reactive substances (TBARs) assays, respectively. The omega-3 fatty acid content of the nanosystems was also evaluated, without significant changes during the storage period. Thus, chia O/W nanoemulsions obtained by microfluidization proved to be suitable delivery systems for bioactive compounds of chia seed, with potential applications in the development of functional food.