CHIA OIL MICROENCAPSULATION IN SOY PROTEIN ISOLATE-GUM ARABIC COMPLEX COACERVATES: FORMULATION AND SPRAY DRYING

GABRIELA BORDÓN; ALEJANDRO PAREDES; NAHUEL CAMACHO; MARIA CECILIA PENCI; AGUSTÍN GONZÁLEZ; PABLO RIBOTTA; MARCELA MARTINEZ

Merida

Conferencia; IV Conferencia Internacional de la Red Chia-Link; 2018

Red Chia-Link

Introduction: Application of complex coacervation between two biopolymers, followed by spray drying for microencapsulation purposes, offers several advantages: through a flexible, economical and scalable operation, a product with high encapsulation efficiency, good thermoresistance and controlled release properties is obtained. Objectives: First, to determine the process conditions (pH, total biopolymer concentration, protein/polysaccharide ratio and ionic strength) that optimize the complex coacervation between soy protein isolate (SPI) and gum arabic (GA) as wall materials for chia oil microencapsulation. Second, to analyze physicochemical properties of the powder obtained by spray drying. Materials and Methods: zeta potential, turbidity and coacervation yield analyses were carried out at different total biopolymer concentrations (4, 8, 12, 16 % w/v), SPI:GA ratio (2:1, 1:1, 1:2) and ionic strength (0, 0.1, 0.5 M KCl) to optimize complex coacervation conditions. Chia oil emulsions were prepared through complex coacervation between wall materials under optimized conditions. The spray-drying process was performed in a laboratory-scaleMini Spray Dryer Büchi B-290 (air atomizing pressure: 4.4 L/h; air inlet and outlet temperature, 130 °C and 80 ± 1 °C, respectively; atomization air flow rate: 538 L/h; pump and aspirator setting, 10% and 100%, respectively). Moisture content, surface oil content, oxidative stability (Rancimat analysis), omega-3 fatty acids profile and final particle size was determined. Results: The optimized conditions for SPI and GA complex coacervation were the following: pH= 3.15, 12 % w/v biopolymer concentration, 2:1 SPI:GA ratio, 0 M KCl, stirring during 30 min at 40 °C. In addition, the physicochemical properties of the final powder were: moisture content, 3.42 ± 0.01%; surface oil: 2.74 ± 0.18 %; oxidative stability: 2.18 ± 0.04 h and 5.86 ± 0.15 h for pure and microencapsulated oil, respectively; no statistical differences were found in fatty acids profiles for both bulk and microencapsulated oils (p