Vanilla is one of the most popular species in the world. Its main compound, vanillin, is responsible for its characteristic aroma and flavor and its antioxidant and biological properties. Vanillin is very unstable in the presence of oxygen, light, and humidity, which complicates its use and preservation. Therefore, to solve this problem, this study aimed to develop vanilla oleoresin microcapsules. Vanilla oleoresin was obtained with supercritical carbon dioxide and microencapsulated by complex coacervation and subsequent spray drying (100 °C/60 °C inlet/outlet temperature). The optimal conditions for the complex coacervation process were 0.34% chitosan, 1.7% gum Arabic, 5.29 pH, and an oleoresin:wall material ratio of 1:2.5. Fourier Transform Infrared Spectroscopy (FT-IR) analysis of the coacervates before and after spray drying revealed the presence of the functional group C=N (associated with carbonyl groups of vanillin and amino groups of chitosan), indicating that microencapsulation by complex coacervation-spray drying was successful. The retention and encapsulation efficiencies were 84.89 ± 1.94% and 69.20 ± 1.79%. The microcapsules obtained from vanilla oleoresin had high vanillin concentration and the presence of other volatile compounds and essential fatty acids. All this improves the aroma and flavor of the product, increasing its consumption and application in various food matrices.

Upon popping, corn kernels undergo substantial dehydration. Initial moisture content of the kernel, popping method and temperature determine the final quality, and physical characteristics of the flakes. In this work, corn kernels (Zea Mays var Everta) at different moisture contents were subjected to hot-air popping and quality, physical and morphometric parameters of the flakes were evaluated, and related with their microstructural features. The best moisture content for hot-air popping was 9.14%. Macro and microstructural examination and digital image analysis of the flakes showed that, at the macro level, the roughness of the different flakes, as given by their fractal dimension (FD), were similar among morphologies, whereas at the microscale, it was possible to differentiate between them. Additionally, at the macro-scale, for the different morphologies high correlations were found between areas and the linear dimensions (Feret or width)^FD of evaluated flakes. Moreover, when using the FD of the microstructures as the exponent, high correlations were also observed, which confirms an analog multiscale behavior between the roughness of the flakes and their microstructures.

Contamination of effluents with chemicals is a serious problem that impacts human health. Methylene blue is a cationic dye found frequently in industrial and urban sewages. In this work, dried grinded seeds and peels of nance were used as biosorbents in aqueous solutions at pH 7 and 10 (simulating urban and textile effluents) finding that Langmuir and Freundlich isotherms adequately described the sorption. Adsorption efficiencies were larger than 98 in all cases and slightly lower at pH 7 due to the closeness with the point of zero charge (pzc) of seeds and peels of nance (5.96 and 3.42, respectively). In all cases, Langmuir adsorption was favorable (R_La<1), and Gibbs free energy of adsorption was negative indicating spontaneity, and since these values were larger than 80 but lower than 0kJ/mol, the MB removal process was mainly due to physical interactions, a characteristic of physical adsorption. No significant differences were found amongst bulk mass transfer coefficients for the adsorption of both sorbents, indicating that both bioadsorbents had the same hydrodynamic and driving forces as well as depicted similar MB-adsorbent affinities. Interaction of MB with adsorbents was corroborated by FTIR spectroscopy, and the sorption was evidenced by scanning electron microscopy and image analysis which indicated that both adsorbents had fractal structures.