Influence of Germination Time on the Morphological, Structural, Vibrational, Thermal and Pasting Properties of Potato Starch from Solanum tuberosum Phureja Group

Abstract

This work focuses on the study of the physicochemical changes that take place during a short germination period in flours and starches of the Creole potato tuber. To this end, the changes in the composition of flours and the structural, thermal, vibrational, functional and pasting changes of the isolated starches from germinated potatoes were evaluated during the 12-day germination period, measured every 4 days. The water absorption index (WAI) and the swelling powder showed no significant changes. Germination resulted in a decrease in fat and ash content, but an increase in protein and amylose content. Scanning electron microscopy (SEM) showed no changes in the morphology of the starch during germination. X-ray diffraction showed that isolated Creole potato starch contains nanocrystals with hexagonal crystal structure, which are not affected by germination. Differential scanning calorimetry (DSC) shows a shift of the gelatinization peak to the right, which could be attributed to the concentration effect. The pasting profiles of the isolated starches show no significant changes, indicating that the starch granules do not suffer any external damage due to the enzymatic process during germination and that the final viscosity behaves like a hydrogel.