Chia oil microencapsulation in soy protein isolate-gum arabic complex coacervates: formulation and spray drying

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

Mérida, Yucatán

Conferencia; I Foro Científico en Salud, Ciencia y Tecnología de los Alimentos - I Conferencia Internacional la VALSE-FOOD - IV Conferencia Internacional CHIA-LINK.; 2018

Red Chia-Link

Introduction:Applicationof complex coacervation between two biopolymers, followed by spray drying formicroencapsulation purposes, offers several advantages: through a flexible,economical and scalable operation, a product with high encapsulationefficiency, good thermoresistance and controlled release properties isobtained. Objectives: First, to determinethe process conditions (pH, total biopolymer concentration,protein/polysaccharide ratio and ionic strength) that optimize the complexcoacervation between soy protein isolate (SPI) and gum arabic (GA) as wallmaterials for chia oil microencapsulation. Second, to analyze physicochemicalproperties of the powder obtained by spray drying. Materials and Methods:zetapotential, turbidity and coacervation yield analyses were carried out atdifferent 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 complexcoacervation conditions. Chia oil emulsions were prepared through complexcoacervation between wall materials under optimized conditions. Thespray-drying process was performed in a laboratory-scale Mini Spray Dryer BüchiB-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 andaspirator setting, 10% and 100%, respectively). Moisture content, surface oilcontent, oxidative stability (Rancimat analysis), omega-3 fatty acids profileand final particle size were determined.   Results: The optimizedconditions 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 30min at 40 °C. In addition, the physicochemical properties of the final powderwere: moisture content, 3.42 ± 0.01%; surface oil: 2.74 ± 0.18 %; oxidativestability: 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 forboth bulk and microencapsulated oils (p