DRYING TEMPERATURE ON THE KINETICS, TECHNOLOGICAL PROPERTIES, AND MORPHOLOGICAL CHANGES OF YACON SLICES

Yacon (Smallanthus sonchifolius) is a promising andean root with high potential as a functional food. However, there are still few studies on the impact of processing on its properties. This study evaluated the effect of drying temperature (Binder ED-56 drying oven) on yacón slices (4 × 5 cm, 3 mm thick), focusing on drying and rehydration kinetics (Page and Peleg models), as well as technological properties such as solubility (ISA) and water absorption index (WAI). Additionally, image analysis was used to determine area and perimeter shrinkage and the degree of darkening through the gray scale index (GSI) and integrated density (DIR and IRD). Increasing the drying temperature accelerated the process, modifying Page model parameters (↑k) and being influenced by the raw material's origin, with activation energies between 20–30 kJ. At 50 °C, rehydration varied by origin, although high water absorption was achieved (especially the Peleg parameter k₂). Peleg parameters were similar to those of other works. Variations in ISA and WAI also suggested structural changes in 50 °C, in contrast to 70 and 90 °C, moisture gain in rehydration, WAI and ISA was relevant with respect to other studies. Higher drying temperatures were associated with reduced browning (indicated by higher gray scale index values) and less shrinkage, as evidenced by smaller changes in projected area. Overall, although high temperatures are typically linked to nutrient loss, this study showed that they enhanced drying efficiency without compromising technological properties or morphological quality.