Microencapsulation of Chia Seed Oil by Spray-Drying: Influence of the Antioxidant Addition

Abstract

Chia seed oil has a high content of polyunsaturated fatty acids, giving it nutritionally beneficial qualities, although determining its high susceptibility to oxidative deterioration. Microencapsulation and natural antioxidants are alternatives to protect this oil during its processing and storage. This work aims to study the physicochemical characteristics and the oxidative stability of chia seed oil microencapsulated with different antioxidants (rosemary extract, blend of rosemary and chamomile extracts, ascorbyl palmitate) by spray-drying using sodium caseinate and lactose as wall material. The microencapsulation efficiency and the moisture content are >97% and <3% d.b., respectively. Scanning electron microscopy shows that the microcapsules are spherical, with diameters ranging between 11.3 and 14.8 µm. At t = 0, the microencapsulated oil recorded a ti = 12.7 h, seven times greater than that of the bulk-oil. The addition of the antioxidants increases the ti of the microencapsulated oil. The addition of ascorbyl palmitate maintains the peroxide value under the acceptable limit after 60 d of storage (25 °C, darkness, HR 33%). Thus, microencapsulation by spray drying of chia oil with ascorbyl palmitate addition will be the most appropriate studied system to obtain microparticles with high efficiency and oxidative stability during the processing and storage. Practical Application: This study contributes to investigating the microencapsulation of omega-3 fatty acids n-3 fatty acids (FAs) from a novel oilseed (chia oil), applying different antioxidants, including those from vegetable sources such as rosemary and chamomile extracts, to confer additional protection to microencapsulated oil. Thus, the application of these techniques will enable the delivery of this vegetable oil for the development of functional foods.