Spray-dried chia oil emulsions encapsulated with sodium caseinate and lactose. Physicochemical properties and stability during storage

IXTAINA VANESA; JULIO LUCIANA; DENISIENIA EDUARDO; WAGNER JORGE; NOLASCO SUSANA; TOMÁS MABEL

Antalya

Congreso; 11th EuroFed Lipid Congress; 2013

European Federation for the Science 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 spray-dried microencapsulated chia oil 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 135/70¨¬C and 170/90¨¬C. Powder samples were spread on Petri dishes and stored in closed chambers without light exposure at relative humidity of 33% and 25¡¾3¨¬C. 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-170/90¨¬C recorded the highest physical stability. The particle size distributions of all E and RE displayed a unimodal distribution. D[4,3] values of RE were similar to those corresponding to the original E, recording the lowest particle size in RE obtained from E at 600 bar (~0,30 ¥ìm). The dispersability of microcapsules 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 a homogeneous suspension. For powders stored at 25¡¾2¨¬C, 40 days the droplet obscuration took slightly longer to reach a constant value of ~12% (600 bar) and 17% (400 bar). Regarding oxidative stability during storage, microcapsules obtained from E at 600 bar showed higher peroxide values (PV) than those at 400bar.