Study of the preparation process and wall components variation in chia (Salvia hispanica L.) oil microencapsulation.

A. GONZÁLEZ; MARCELA MARTINEZ; ALEJANDRO PAREDES; ALBERTO E. LEÓN; PABLO RIBOTTA

POWDER TECHNOLOGY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2016 vol. 301 p. 868 - 875

0032-5910

A study of the microencapsulation process of omega-3 rich oil extracted from chia (Salvia hispanica L.) seeds wascarried out,which included a comparative analysis of the microcapsules obtained by the spray- and freeze-dryingmethods using isolated soy proteins and maltodextrin aswall materials at different proportions. Color characterizationof the obtained powders was performed and revealed a darker and yellower appearance of the freezedriedsamples compared with the spray-dried ones. Moisture contentwas measured for each sample and all presentedvalues around 3.5%. The SEMmicrographs revealed that spray-dried microcapsules can occur individuallyor may form clusters or aggregates, with the particles exhibiting a size range varying from 4 to 10 μm. Encapsulationefficiency was measured,with no significant differences found between drying methods or on varying theproportion of wall components (all samples presented values of approximately 60%). The oxidative stability ofmicroencapsulated oils under accelerated oxidative conditions revealed protection factors 2-fold higher for allsamples. In addition, microencapsulated oil stored under 25 °C revealed lower hydroperoxide values thanthose of unencapsulated oil throughout the whole storage test. Finally, oil encapsulated in SPI microcapsulesalso showed lower HPV values than that of the acceptable limit for virgin and cold-pressed vegetable oils(15 meq. O2/kg oil) during the storage test, while unencapsulated oil attained the acceptable limit in 62 days.This result represents an increase in the time of the oil shelf life of between 30 and 48%.