Effect of Different Wall Materials on the Physicochemical Properties of Spray-dried Microencapsulated Chia Oil

MEDINA, U. U. ; IXTAINA V; JULIO, LM; J.R.WAGNER; NOLASCO, SM,; SEGURA CAMPOS M; TOMAS, MC

Orlando

Congreso; 106th AOCS Annual Meeting & Industry Showcases; 2015

AOCS

The objective of this work was to study the influence of composition of the wall material on the physicochemical and oxidative stability of spray-dried microencapsulated chia oil. Chia seed oil (10%wt/wt) was homogenized using a high pressure homogenizer (600 bar) with different wall material solutions at a core/wall material ratio of 0.33: sodium caseinate+lactose (NaCas+Lac), NaCas+maltodextrin (NaCas+Mx), Mx+chia proteins (Mx+Prot), with and without the addition of chia mucilage (Muc). These emulsions (E) were microencapsulated by spray-drying at inlet/outlet temperatures of 170/90ºC. The encapsulation efficiency was: NaCas+Lac+Muc (96.2±0.4%)>NaCasLac(95.2±0.4%)>NaCas+Mx+Muc(86.6±0.2%)>NaCas+Mx(71.3±0.1%)>Mx+Prot(57.7±3.0%)> Mx+Prot+Muc (53.4±1.0%). The moisture content of microcapsules ranged between 2.7-4.5% d.b., while water activity (aw 25ºC) was 0.31-0.43. The particle size distributions of all E and reconstituted emulsions (RE) displayed a unimodal distribution, except Mx+Prot and Mx+Prot+Muc, which were bimodal. The lowest D[4,3] values of E and RE were those corresponding to NaCas+Lac+Muc and NaCasLac (~0,3 μm), whereas the highest were those of Mx+Prot and Mx+Prot+Muc (~19,0 μm). The dispersibility of microcapsules was assessed following the change in droplet obscuration as a function of time (5 min). The accelerated oxidative test (Rancimat) revealed the highest induction time value for microcapsules formulated with NaCas+Mx+Muc and NaCas+Mx (~13h), being this value about six times higher than that of bulk oil (~2 h)