Preparation of Corn Starch Nanoparticles by Wet-Stirred Media Milling for Chia Oil Vehiculization

BORDÓN, MARÍA GABRIELA; MARCELA L. MARTÍNEZ; FABRIZIO CHIARINI; RODRIGO BRUSCHINI; CAMACHO, NAHUEL MATÍAS; HERNÁN SEVERINI; PALMA, SANTIAGO DANIEL; PABLO D. RIBOTTA

La Plata y Jujuy

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

An organic-free method was applied to produce corn starch nanoparticles, which weredesigned to stabilize Pickering emulsions containing chia oil, the richest vegetable source of omega-3fatty acids. The liquid stream resulting from a laboratory-scale mill assisted by zirconia beads wasfiltered, centrifuged and homogenized to prepare the continuous phase of the emulsions. Experimentswere performed as follows: 24 h (milling time), 0.1–0.2 mm (beads’ diameter), 1600 rpm (impellerspeed), 25% (volume occupied by the grinding media), 1–7% w/v (starch concentration) and 0–1% w/vof sodium dodecyl sulfate (SDS). Particle sizes in the obtained nanosuspensions were reduced from376–432 nm to 160–200 nm after centrifugation and homogenization. The product formulated with0.01% w/v of SDS showed the most stable particle size during storage. Hence, this latter formulationwas selected to prepare Pickering emulsions. Oil droplets showed surface mean diameters andpolydispersity indexes of 283.33 ± 1.53 nm and 1.36 ± 0.03, respectively, with no significant variationsduring storage for around two weeks. Finally, nanosuspensions containing 7% w/v of starch, andthe above three concentrations of SDS, were filtered, centrifuged, homogenized and spray-dried toobtain redispersible powders able to stabilize Pickering emulsions. The most stable particle sizeafter redispersion (385.83 ± 5.85 nm) was obtained with the highest concentration of SDS. Moreover,SEM images revealed the presence of round-shaped particles with sizes below 1 µm. These resultshighlight that wet-stirred media milling can be applied as a green-method to produce new food-gradestarch nanoparticles, which are able to deliver bioactive compounds from chia oil.