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

MARÍA G. BORDON; MARCELA LILIAN MARTÍNEZ; FABRIZIO CHIARINI; RODRIGO BRUSCHINI; NAHUEL CAMACHO; HERNÁN SEVERINI; SANTIAGO DANIEL PALMA; PABLO DANIEL RIBOTTA

Biology and Life Science Forum

MDPI

Año: 2022

2673-9976

An organic-free method was applied to produce corn starch nanoparticles, which were designed to stabilize Pickering emulsions containing chia oil, the richest vegetable source of omega-3 fatty 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. Experiments were performed as follows: 24 h (milling time), 0.1–0.2 mm (beads’ diameter), 1600 rpm (impeller speed), 25% (volume occupied by the grinding media), 1–7% w/v (starch concentration) and 0–1% w/v of sodium dodecyl sulfate (SDS). Particle sizes in the obtained nanosuspensions were reduced from 376–432 nm to 160–200 nm after centrifugation and homogenization. The product formulated with 0.01% w/v of SDS showed the most stable particle size during storage. Hence, this latter formulation was selected to prepare Pickering emulsions. Oil droplets showed surface mean diameters and polydispersity indexes of 283.33 nm and 1.36, respectively, with no significant variations during storage for around two weeks. Finally, nanosuspensions containing 7% w/v of starch, and the above three concentrations of SDS, were filtered, centrifuged, homogenized and spray-dried to obtain redispersible powders able to stabilize Pickering emulsions. The most stable particle size after redispersion (385.83nm) was obtained with the highest concentration of SDS. Moreover, SEM images revealed the presence of round-shaped particles with sizes below 1 um. These results highlight that wet-stirred media milling can be applied as a green-method to produce new food-grade starch nanoparticles, which are able to deliver bioactive compounds from chia oil.