JULIO Luciana Magdalena
congresos y reuniones científicas
Microcapsules of chia oil obtained by spray-dryer. Physicochemical properties and stability during storage
IXTAINA, VANESA Y.; JULIO, LUCIANA M.; WAGNER, JORGE R.; NOLASCO, SUSANA M.; TOMÁS, MABEL C.
Congreso; 11th Euro Fed Lipid Congress and 30th ISF lecture series; 2013
European Federation for the Sciencie and Technology of Lipids
Microencapsulation is an alternative to protect chia oil from the adverse influence of the chemical environment, since this oil is very susceptible to oxidation due to their high content of PUFAs. The objective of this work was to study the influence of the operative conditions on the physicochemical and oxidative stability of chia oil microcapsules (M) during storage. O/W emulsions (E) were prepared with 10%wt/wt sodium caseinate, 10%wt/wt lactose and 10%wt/wt chia oil using a high pressure homogenizer at 400 and 600 bar. These E were spray-dried at inlet/outlet temperatures of 135/70ºC and 170/90ºC. Powder samples were spread on Petri dishes and stored in closed chambers without light exposure at relative humidity of 33% and 25±3ºC. Stability of the reconstituted emulsions (RE) at 10, 24 and 40 days was evaluated through the evolution of backscattering profiles (%BS), particle size distribution, and mean particle diameters (D[4,3]). The encapsulation efficiency was >90% in all cases. Samples obtained at 600bar-170/90ºC recorded the highest physical stability. The particle size distributions of all E and RE displayed an unimodal distribution. D[4,3] values of RE were similar to those corresponding to the original E, recording the lowest particle size in M obtained from E at 600 bar (~0,30 μm). The dispersability of M was assessed by measuring the change in droplet obscuration as a function of time. The obscuration increased steeply with agitation time up to 1.5 min, after which it reached a fairly constant value of ~10% (600 bar) and 15% (400 bar). The rapid increase in obscuration indicated that the majority of the powder dispersed rather quickly, producing an homogeneous suspension. For the powders stored at 25±3ºC, 40 days the droplet obscuration took slightly longer (2.5 min) to reach a constant value of ~12% (600 bar) and 17% (400 bar). Regarding oxidative stability during storage, M obtained from E at 400 bar showed higher peroxide values (PV) than those at 600bar.