Extraction and characterization of starch from Dioscorea species cultivated in the Amazon

Abstract

Considering the development of products using regional raw materials, the starches of Dioscorea alata L. and D. altissima Lam. were extracted and characterized. The parameters analyzed were: yield, composition, morphology and size of the granules, physicochemical composition, technological properties, in vitro toxicity, and microbiological analysis. A significant yield (8.57%) was observed in D. altissima. Available starch (75.02%), total (84.63%) and amylose (19.15%) were higher in D. alata. Starch resistant (10.10%) and amylopectin (82.09%) were superior in D. altissima. pH and acidity did not vary between samples. Water activity was lower in D. alata. Low moisture, ash, lipid, protein, fiber, and high carbohydrate contents were observed. The starches did not present cytotoxicity or microbial contamination. The granules of D. altissima starch are spherical and significantly larger. In D. alata and D. altissima starches, macro- and microminerals are predominant, respectively. Water absorption (85.73 g 100 g^-1), oil (67.13 g 100 g^-1), foam stability (100%), and pulp clarity (2.87%) were higher in D. alata. The swelling capacity (4.07 g g^-1) and bulk density (0.87 g mL^-1) were higher in D. altissima. The studied starches have technological properties with potential for the food industry, medicines and packaging.