Physical, functional, and pasting properties of flours from corms of two Cocoyam (Colocasia esculenta and Xanthosoma sagittifolium) cultivars.

Abstract

Physical, functional and physicochemical properties of flours of five cocoyam (Colocasia spp and Xanthosoma spp) cultivars were evaluated. Colour (L*a*b*) parameters of corms and flours, pasting and functional properties of the flours were determined. Xanthosoma spp showed significantly higher length (95.16-151.46), width (75.29-78.03) and weight (179.20-605.94) than the Colocasia spp., but the parameters did not vary significantly within either Xanthosoma and Colocasia spp. Generally, colour of peeled corms [L* (72.08-78.93); a* (+1.06 - +3.5); b* (+17.65 - +35.80)] was lighter than the flours [L* (69.35-84.97); a* (+0.30 - + 4.76); b* (+4.44 - +23.48)]. The NXs001 showed significantly higher peak (201.71RVU), trough (186.75 RVU), final (289.75 RVU) and setback (103 RVU) viscosities that the other cultivars. Pasting profiles of the cocoyam flours showed similar trend with the NXs001 showing a steeper curve. Pasting temperature and peak time ranged from 87.33 to 92.53°C and 5.17-6.34min, respectively. Water absorption capacity, gelling point, pH, foam capacity, bulk density and swelling power varied from 32-69%, 6.56-7.59, 58.5-72.5°C, 7.19-14.72%, 0.94-1.01g/mL and 3.18-7.36, respectively.