Structural, Thermal, and Morphological Characterization of Chickpea (Cicer arietinum L.) submitted to the hydration process

Abstract

Chickpea is a legume of great added value, and the hydration process is an essential step in its processing and improvement of cooking and consumption characteristics. In the present work, chickpeas were characterized in natura and hydrated at different temperatures to verify the structural and morphological changes caused by the hydration process. The in natura grains were subjected to hydration for 4 hours at temperatures of 50°C, 60°C, 70°C, and 80°C. Then, they were characterized for crystallinity (XRD), thermal stability (TG and DTG), and morphology (SEM). The results of the characterization by X-ray diffraction allowed us to verify that the samples of in-natura and hydrated grains presented diffractograms characteristic of legumes, with standard C starch, and percentages of crystallinities that reduced their values with increasing hydration temperature. The results of the characterization by thermogravimetric analysis (TGA) and its derivative (DTG) provided the temperature values at which the phenomenon of dehydration occurs, as well as the degradation events of the polysaccharides present in the different samples of in-natura and hydrated chickpeas. While the micrographs (SEM) identified that the increase in hydration temperature caused the gelatinization of the starch present in the chickpeas, making the grain structures with amorphous characteristics.