Structural and physicochemical characteristics of Peruvian carrot (Arracacia xanthorrhiza) starch

Starch has very important physicochemical properties that depend on its botanical source and structural characteristics. Peruvian carrot starch displays special characteristics, which make it appropriate for industrial application in many processed foods. In this work, starch from two Peruvian carrot varieties, Amarela de Carandai (AC) and Amarela de Senador Amaral (ASA), were isolated and their physicochemical and structural properties were determined. Starch from the ASA variety exhibited granules with a greater average diameter than those from the AC variety and more than double the number of granules with size >= 20 mu m, when compared to the other variety Starches from both varieties, observed in a Scanning Electron Microscope, showed smooth granule surface with circular and polyhedral shapes for large and small granules, respectively. Molecular size distribution, intrinsic viscosity and degree of cristallinity of starches from both varieties were similar; however, amylose content was higher for the starch from the AC variety. Higher values of viscosity, swelling power and gelatinization temperatures were observed for the starch from the ASA variety, which could be related to the lower amylose content and the higher proportion of large granules exhibited by this starch.