Study of Different Wall Matrix Biopolymers on the Properties of Spray-Dried Pequi Oil and on the Stability of Bioactive Compounds

This work aimed to evaluate the effect of the partial replacement of whey protein isolate (WPI), by maltodextrin (MD) and by inulin (IN), on the characteristics of spray-dried pequi oil and on the degradation of its bioactive compounds. Three treatments, WPI, WPI/MD (1:1), and WPI/IN (1:1), were carried out, and the characteristics of the emulsions and microparticles were evaluated. In addition, thermal analysis, X-ray, and scanning electron microscopy of microparticles were carried out. It was found that the solubility of the encapsulations was affected by the composition of the wall material and reached higher value (88.26%) when IN was applied. The encapsulation efficiency (74.49%) was lower with IN. The particles presented amorphous characteristics, and the treatments WPI and WPI/IN exhibited smoother and spherical morphology. WPI and WPI/MD showed greater thermal stability and also better protection of the antioxidative capacity of the oil through the beta-carotene bleaching assay. The WPI system showed better protection of beta-carotene, delta-carotene, and lycopene, compared to the bulk oil, while WPI/MD protected better the gamma-carotene and WPI/IN showed better protection of alpha-carotene.