Physicochemical Characterisation of Starches from Six Potato Cultivars Native to the Colombian Andean Region

We isolated and investigated the starch of six potato cultivars (Solanum tuberosum), grown in the Andean region in the south of Colombia, to determine their physicochemical properties. The potato cultivars are known by their common names as Mambera, Ratona, Pastusa, Capiro, Unica and Roja-huila. The minerals, amylose content, water absorption and water solubility of the starches were evaluated. Morphology, crystalline structure, gelatinisation, thermal degradation and viscosity were also determined. The results showed that Capiro starch has a high mineral content. The apparent amylose and phosphorus contents in starch isolated from Mambera, Ratona and Pastusa were higher than those from Unica and Roja-huila. The starches with higher amylose content and better-defined peak in X-ray diffraction (XRD) (Mambera, Ratona and Capiro) had higher gelatinisation temperatures and took more time to reach the viscosity peak. All starches have hexagonal crystalline structure (B-type). The final viscosity of starches isolated from Mambera and Ratona was higher than that from Unica, Roja-huila and Pastusa due to their higher apparent amylose content.