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Omega–3 encapsulation by PGSS-drying and conventional drying methods. Particle characterization and oxidative stability

Melgosa, Rodrigo, Benito-Román, Óscar, Sanz, María Teresa, de Paz, Esther, Beltrán, Sagrario
Food chemistry 2019 v.270 pp. 138-148
ascorbic acid, differential scanning calorimetry, encapsulation, freeze drying, glass transition, melting, microparticles, oils, omega-3 fatty acids, oxidation, oxidative stability, peroxide value, polyunsaturated fatty acids, powders, spray drying, storage temperature, storage time
Particles from Gas-Saturated Solutions (PGSS)-drying has been used as a green alternative to encapsulate omega–3 polyunsaturated fatty acids (n–3 PUFAs) at mild, non-oxidative conditions. PGSS-dried particles have been compared to those obtained by conventional drying methods such as spray-drying and freeze-drying, finding encapsulation efficiencies (EE) up to 98% and spherical morphology for PGSS- and spray-dried particles. Freeze-dried powders showed irregular morphology and EE from 95.8 to 98.6%, depending on the freezing method. Differential scanning calorimetry (DSC) analysis revealed glass-transition and melting peaks of OSA-starch and a cold-crystallization peak corresponding to the encapsulated n–3 PUFA concentrate. Compared to conventionally dried powders, PGSS-dried microparticles showed lower primary and secondary oxidation after 28 days of storage at 4 °C. Ascorbic acid addition combined with the mild processing conditions of PGSS-drying yielded particles with a maximum peroxide value of 2.5 meq O2/kg oil after 28 days of storage at 4 °C.