Luciana de Matos Alves Pinto

Caracterização física e química das frações do fruto atemoia Gefner

The atemoya is a hybrid fruit derived from the cross between the sugar apple (fruta-do-conde), better known as ata (Annona squamosa L.) with the cherimoya (Annona cherimola Mill.). The aim of this research was to characterize the chemical constituents of the fractions skin, pulp and seed of the hybrid fruit atemoya, variety Gefner. The fruits purchased and selected were weighed and measured. They were separated into skin, pulp, seed and floral axis which were also weighted to determine their proportions. For the rest of the fruits, the fractions were separated into 7 replicates of 13 fruits. Then, the fractions skin, pulp and seeds were freeze-dried and stored in freezer. The proportion of the fruit fractions, the centesimal composition, ascorbic acid, total sugars, minerals and some bioactive compounds were determined. The pulp represented about 60% of the fruit weight, while the skin 28.13% and the seeds 8.34%. The fruit presented on the average 56 seeds, with longitudinal diameter of 10.79 cm and transversal diameter of 26.64 cm. The largest contents of crude protein, ether extract and dietary fiber were found in both seeds and skin. The skin stood out in the ash contents. The pulp showed the highest contents of ascorbic acid and total sugars in relation to the other fractions. The order of the composition of macronutrients in the skin, pulp and seeds of the atemoya was K>P>Ca>Mg; for the skin and seed micronutrients were Fe>Zn>Cu>Mn>S and in the pulp were Fe>Zn>Mn>Cu>S. The skin presented the highest levels of trypsin inhibitors and hemagglutinating activity. The phenolic compounds were relatively low in the fruit.

Complexes between methyltestosterone and β-cyclodextrin for application in aquaculture production

The inclusion complexes between 17-α-methyltestosterone (MT) and β-cyclodextrin (bCD) were prepared and characterized in dissolution and solid phase. The complex promoted a sixfold increment in solubility of the hormone. It has a limited solubility and stoichiometry of 2:1 (bCD:MT) determined by DSC, NMR and solubility experiments, the association constant Ka=2846Lmol-1 and complex fraction of 76% (assessed by DOSY-NMR, in (1:3) DMSO/D2O). The association constant obtained in water by the solubility isotherms is 7540Lmol-1. 2D-ROESY experiments indicate the intermolecular orientation (complete inclusion of the hormone in the cavity). Simulations by molecular dynamics agreed with the formation of the inclusion complex 2:1. Release tests showed the slower release for the complexes, with 50% for lyophilization and 56% for malaxation. These results clearly demonstrate the complexation of MT in bCD, which formulations are promising for further applications involving this steroid in aquaculture, both for sexual reversal and in technologies of hormone in water sequestration.

OBTENÇÃO E CARACTERIZAÇÃO DE MATERIAL HÍBRIDO ENTRE SÍLICA E CICLODEXTRINAS

The obtention of silica and cyclodextrin hybrid materials was accomplished by refluxing them in xylol using citric acid as a binding agent. The materials were characterized by infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and elemental analysis. Evidence for the docking of cyclodextrins α and γ was substantiated based on the variation in band intensity for groups such as ≡Si-OH. Additional docking evidence includes the displacement of some of the bands that are related to cyclodextrin such as the deformation of the C-H axial bond. The α and γ-CDSi materials were characterized as amorphous compounds. The products obtained in the synthesis showed changes in the decomposition temperatures of their isolated constituents, in which the mass of α and γ-CD docked to the silica surface gave the estimated values of 41% and 47%, respectively. The elemental constituents were shown to be consistent and close to their relative theoretical values. ​Thermogravimetric analysis showed that a reduction in the percentage of the hybrids was proportional to the amount of lost mass. This new material is an improvement over synthesized organosilane materials because the operator and the environment benefit from a less toxic methodology. In addition, the material has several potential applications in complexation systems with cyclodextrin.