Thermal and structural study of guava (Psidium guajava L) powders obtained by two dehydration methods

two food products (powders) were obtained by hot-air drying or lyophilisation methods on the whole guava fruits. the powders were characterised by sensory and thermal analyses (tga-dsc), infrared spectroscopy (ir), x-ray diffraction (xrd) and scanning electron microscopy (sem). thermal, morphological and structural characterisations showed a similar behaviour for the two solids. tga-dsc and ir showed the presence of pectin as the main constituent of solids. a semi-crystalline profile was evidenced by xrd, and lamellar/spherical morphologies were observed by sem. sensory analyses revealed an aroma highly related to guava. these value-added food products are an alternative to process guava and avoid loss during postharvest handling.