Microencapsulação de fitoesterol associados a óleos essenciais por spray drying para aplicação em produtos funcionais

Abstract

Consumers have been looking for other features in the foods they consume that go beyond simply nourishing, with functional foods being a viable option in this sense. Phytosterols found in plants may be an option, as they have a chemical structure similar to that of cholesterol, and therefore contribute to lowering its level in the blood by competing for its absorption in the intestine. However, phytosterols are nonpolar and therefore difficult to homogenize in water-based foods and beverages. One of the techniques used to improve the incorporation of lipid compounds in hydrophilic foods is using biopolymers that act at the interface facilitating their dispersion and solubilization. Also, nutritional oils such as coffee oil and coconut oil can be used to contribute to the sensory attribute of these products. Therefore, the objective of this work was to microencapsulate a phytosterol ester extracted from soybeans by spray drying and to physicochemically characterize the particles. As wall material, whey protein isolate (IPS) and maltodextrin (D20) (1:1) were used, associating different concentrations of coffee oil and coconut oil. Two emulsifiers were also used, one based on diacetyl tartaric acid esters of mono and diglycerides (DATEM) and the other, sodium dodecyl sulfate (SDS) at a concentration of 2.5% (m/m). The different formulations were evaluated for emulsion stability, and the particles were characterized for mean particle diameter, morphology, water activity, moisture, amount of total oil, surface oil and microencapsulation efficiency (EM) and bulk density, as well as hygroscopicity, solubility, and water sorption (isotherm) properties were studied. The use of emulsifiers has proven to be effective to ensure the stability of emulsions. The microencapsulation efficiency was between 47.44 and 54.25%, with the highest retention in samples containing higher concentrations of phytosterol in the formulation. The low hygroscopicity and low water activity of the particles indicate that the product has good stability and low risk of microbial deterioration. The results of the hot solubilization time (98ºC) and the high concentration of oil on the surface of the particles suggest the presence of a superficial oil layer that directly influences the solubility of the microparticles. Samples SC17F, DC17F, D22F and S22F would be the ingredient choice options to be incorporated into functional food products.