Physical, chemical, and thermal properties of chia and okra mucilages.

The present study aims to investigate the physical, chemical, and thermal properties of chia (CM) and okra (OM) mucilages powders. The mucilages were extracted and dehydrated at 70 °C; then they were evaluated for the profile of total phenolic compounds and mineral profile, colorimetric parameters, morphology by scanning electron microscopy (SEM), infrared by fourier transform (FTIR), X-ray diffraction (XRD), and thermal properties by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA/DTG). It was found that OM had higher amounts of total phenolic compounds, mainly flavonols, with a predominance of quercetin 3-glucoside. On the other hand, CM had the highest content of flavonoids, the most significant being catechin. CM had the highest mineral content, being surpassed by okra mucilage in terms of calcium and copper. The OM had the highest luminosity, with values tending toward yellow and green tones, while the CM was darker and presented yellow and red tones. The mucilages presented morphologically irregular particles with different sizes and shapes, with an amorphous structure. The FTIR showed the bands of the main components, indicating that the mucilages are constituted mainly by polysaccharides (OM), pectins, and soluble proteins (CM). The DSC showed sharp endothermic peaks, indicating greater uniformity and purity of the samples. The thermogravimetric curves and their derivatives showed the greatest mass loss in the second evaluation phase for both materials, followed by the carbonization of organic matter and the formation of fixed mineral residue. The study revealed that mucilages have distinct characteristics, but with excellent properties, which offers great potential as a raw material for industry. [ABSTRACT FROM AUTHOR]