Dioscorea dumetorum Pax as an Alternative Starch Source for Industrial Applications

Abstract

The increasing use of starch as alternative raw material for petroleum based chemical has been creating pressure on the food chain as most starches are obtained from food sources like cassava. There is therefore need to secure alternative starch source from non-edible underutilized plant materials. This study seeks evaluate the suitability of starch extracted from wild bitter yam (DioscoreadumetorumPax) for industrial applications, by comparing its physicochemical properties with that of cassava starch. Results revealed that bitter yam starch has relatively better physicochemical parameters. It possesses a desirable lower moisture content of 10.69±0.09% against 12.38±0.03% of cassava starch. Amylose/amylopectin percentage ratio was 75.79±1/24.21±1.00 and 78.40±1.77/21.60±1.77 for bitter yam and cassava starch respectively. Furthermore, the higher swelling capacities, moisture sorption capacity and gelatinization temperature recorded for bitter yam starch are pointer to its potential in certain food-related applications; paints, paper and adhesives production; and as pharmaceutical excipients. The ash content and pH was found to be 0.437±0.15% and 6.9±0.2 for bitter yam starch while cassava starch recorded 0.418±0.17% and 8±0.4. All the obtained values are within the recommended official specification for starch and suggest that bitter yam starch could be a promising source of cheap starch for industrial uses.