Textural,Color, Hygroscopic,Lipid Oxidation,and Sensory Properties of Cookies Containing Free and Microencapsulated Chia Oil

Encapsulation of chia oil might protect omega-3 and omega-6 from lipid oxidation when producing baked foods. However, the actual gain in stability given by chia oil must be determined. In this work, chia oil or chia oil-loaded microparticles were added to a cookie formulation in order to evaluate the ability of the microcapsules in protecting chia oil from deterioration. Texture, color, water sorption isotherms, and sensorial properties were also evaluated. A hot homogenization technique was used with carnauba wax as an encapsulant, and the freeze-dried microparticles were incorporated into the cookie dough. Principal component analyses were carried out to evaluate lipid oxidation using the medium infrared spectra of the lipid fraction extracted from the baked cookies. It was found that the microencapsulated chia oil was better protected from oxidative deterioration during baking compared to the sample containing non-encapsulated chia oil. Textural analysis showed that chia oil (free and microencapsulated) acted as a coating on the wheat flour particles. Control cookies (no chia oil loaded) presented a more hydrophilic character. In the case of oil-loaded samples (free and microencapsulated), the isosteric heat of sorption behavior indicated an initial swelling step of the food polymers, resulting in the exposure of sorption sites of higher binding energies not previously available, and that this is because of the wheat particles being covered by the chia oil and the solid lipid microparticles. Furthermore, food acceptability did not change when the oil-loaded microparticles were added to the cookie formulation.