Development of a supercritical carbon dioxide assisted impregnation method for the microencapsulation of chia oil

J. PEREYRA CARPINETTI; N. GAÑAN; MARCELA MARTINEZ; PABLO RIBOTTA; AGUSTÍN GONZÁLEZ

Lisboa

Conferencia; II International Conference of la ValSe-Food Network; 2019

Red Chia-Link

Chia seeds, with 32-39% oil, are the richest vegetable source of omega-3 fatty acids (61-70%). The incorporation of these oils into processed foods presents many drawbacks due to oxidative stability issues that affect the nutritional and organoleptic quality of the food. A technology capable of preventing these drawbacks is microencapsulation. An alternative, novel and more environmentally friendly microencapsulation method is supercritical CO2 assisted impregnation. In our study, isolated soy protein was used as wall material and different systems were performed varying pressure and temperature conditions (100-160 bar, 40-60 °C, with or without ethanol as cosolvent). The optimal operating conditions were determined and the impregnated microcapsules were studied and characterized. Microcapsules with retention efficiency (%ER) close to 40% and encapsulation efficiency (%EE) higher than 90% were obtained. The microcapsules obtained showed spherical shape and sizes around 8 microns without the presence of pores or fissures. The microencapsulation process did not generate adverse effects on the chemical quality of the oils, showing hydroperoxides values and relative amounts of fatty acids equal to those presented by oils of optimum chemical quality. The influence of the storage time was studied, showing excellent stability of the microencapsulated samples with respect to oils without encapsulating, thus evidencing a marked protective effect provided by the microcapsule. At the same time the release of the microencapsulated oil was studied under simulated gastrointestinal conditions, finding that 93% of the contained oil is released.