• aroid flours;
  • flours;
  • functional properties;
  • nonconventional flours;
  • proximate composition

ABSTRACT:  The physical proximate composition and physicochemical characteristics, microbiological stability, and in vitro alpha-amylolysis rate of flours produced by conventional dehydration techniques of the edible portions of the aroids Xanthosoma sagittifolium and Colocasia esculenta were investigated. Flours from the edible portion of both tubers did not show significant statistical differences in moisture, Aw, crude protein, total sugars, amylose, and amylopectin contents. C. esculenta flour showed higher crude fat, total, soluble, and insoluble dietary fiber, and mineral (P, Ca, Fe, and Zn) contents, whereas X. sagittifolium flour showed higher starch, ash, and reducing sugar content than its counterpart. With regard to physical and physicochemical characteristics, X. sagittifolium flour showed higher titratable acidity and relative density values, being darker and more yellowish than its counterpart. On the other hand, X. sagittifolium flour showed higher gelatinization temperature than C. esculenta flour. Parameters such as viscosity during the holding time (95 °C for 30 min), viscosity at 50 °C, setback, and consistency were lower in C. esculenta flour than X. sagittifolium flour. The viscosity peak and breakdown indexes were higher in C. esculenta flour than in the X. sagittifolium sample. The colony forming units (CFU) of the microorganisms were much lower than those reported in the literature for similar products. Moreover, due to their moisture content and water activity, these flours could be classified as dry foods and they are shelf-stable foods. The results reflect that flours with good chemical, physicochemical, and nutritional quality and satisfactory microbiological stability may be produced from these aroids.