Study of Physicochemical, Morphological, Functional, Rheological and Thermal Properties of Native Andean Potato Starch and its Application in Biobased Materials

Starch is the most widely used biopolymer for packaging production. Starch obtained from native potatoes (Solanum phureja) may represent an alternative for the development of packaging materials due to its biodegradable nature, providing a potential use that may encourage the cultivation and valorization of these varieties. The objective of this study was to characterize starch from the potato varieties Curiquinga, Ratona Roja (Solanum phureja), and Diacol Capiro (Solanum tuberosum), and to evaluate the mechanical properties of starch-based films produced from these starches. The methodology consisted of determining moisture content and functional indices by gravimetry, granule size and morphology by scanning electron microscopy, amylose content by spectrophotometry, the amylographic profile by rapid viscosity analysis, and thermal properties by thermogravimetry and differential scanning calorimetry. The films were prepared using the casting method. The results showed that the amylose content of Ratona Roja and Diacol Capiro starches was 2% higher than that of Curiquinga starch, possibly due to their larger granule size. Ratona Roja starch exhibited lower water absorption index, swelling power, and maximum viscosity; however, its water solubility index and final viscosity were higher compared with the other varieties. The mechanical properties of films prepared with Ratona Roja starch showed greater elongation at maximum force (%) and Young’s modulus (MPa), whereas tensile strength (MPa) was higher in films prepared with Diacol Capiro potato starch. It is concluded that the functional indices, viscosity profile, and thermal properties may be associated with amylose content and granule size, and these properties determine their potential applications. Starches from native potatoes may be an alternative biopolymer for the production of biodegradable materials.