The Effect of Temperature and Concentration on the Kinematic Viscosity of Starch Gels from Andean Potato Varieties

Native Andean potatoes (Solanum tuberosum subsp. andigenum) are a valuable phytogenetic resource due to their compositional diversity and adaptation to high-altitude environments. Their starch is a key functional polysaccharide widely used in food systems; however, information on the kinematic viscosity of dilute gels under moderate thermal conditions remains limited. This study evaluated the effects of temperature (26, 36, and 46 °C) and starch concentration (1–3% w/v) on the kinematic viscosity of gels from three Andean potato varieties: Imilla Negra, Compis, and Peruanita. Starch was extracted from fresh tubers (Puno, Peru) using a wet extraction method, and gels were prepared by heating dispersions at 85 °C for 5 min under controlled conditions. Viscosity (0.61–34.47 cSt) decreased with increasing temperature and increased with concentration, confirming the sensitivity of these systems to thermal and compositional factors. The Arrhenius model adequately described temperature dependence, with activation energies of 15.19–29.75 kJ·mol−1, showing an increasing trend with concentration. At 3% and 26 °C, viscosity followed Compis > Imilla Negra > Peruanita, indicating varietal differences in thickening capacity. These results provide useful rheological data for the design and optimisation of food processes involving dilute Andean potato starch dispersions.