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AbstractIn this study, the spray drying technique was used to prepare L-ascorbic acid (AA) microparticles encapsulated with galactomannan-an extract from the seeds of the Delonix regia species. The physico-chemical characteristics, antioxidant activity, and encapsulation efficiency of the AA microparticles were evaluated and characterized using thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The free-radical scavenging activity of the AA microparticles was determined at different environmental conditions using DPPH (1,1-diphenyl-2-picryl-hydrazyl). X-ray diffraction measurements demonstrated a loss of crystallinity in AA after the encapsulation process, and a DSC scan also showed the loss of the compound's melting peak. Thermogravimetric analysis showed small differences in the thermal stability of galactomannan before and after the incorporation of AA. The mean diameters of the obtained spherical microspheres were in the range of 1.39 ± 0.77 µm. The encapsulation efficiency of AA microparticles in different environmental conditions varied from 95.40 to 97.92, and the antioxidant activity showed values ranging from 0.487 to 0.550 mg mL-1.

Melon is one of the most widely consumed fruits in the world. In Brazil, 60% of the production is for domestic consumption, with these fruits deemed to be of lower commercial value. For the first time, pectin has been extracted from this species of melon. So the extraction of this polysaccharide can be used as an alternative to increase the value of the fruit, improving profits in the domestic market where it can be used in many industries. The goal of this study is to determine, quantify, characterize and chemically modify by sulfation pectin from common melon for eventual application as an antithrombotic agent. The acidic, basic and neutral extractions yielded an average of 11%, 14% and 8% respectively. The FTIR spectrum revealed that pectin has a low degree of esterification (DE). The bands which appeared at 833 cm-1 and 1251 cm-1 can be attributed to the vibrations of C-O-S and S=O respectively, showing that the material was sulfated. The 13C NMR spectrum showed consistent carbon galacturonic acid peaks and agrees with the FTIR data and elemental analysis for the sulfation of pectin. The molecular weight (MW) determined by GPC was 7.7 x 105 g mol-1, consistent with pectin.