Abstract

Starches fractionated from red and white cocoyams, giant taro, Ghana cocoyam and local cassava (Yaro) were studied for their physical, chemical and physico-functional characteristics. All starches exhibited low crude protein (0.33 to 0.48%), low fat (0.37 to 0.96%), low ash (0.26 to 0.45%), crude fibre - nil, low bulk densities, very high starch and dry matter (93 to 95%), high gelatinization rate, high peak viscosities, short pasting time (11.3 to 32.0 mm), low breakdown (7.65 to 102.50 BU), moderate consistency (35 to 55 BU), low swelling capacities at 50 and 60°C, with each showing its maximum swelling capacity at 90°C. Cocoyam starches are more resistant to swelling at 50 to 70°C than other starches. At 90°C, cassava and red cocoyam starches displayed lower swelling capacities of between 200 to 250 g water absorbed/100 g. Observably, starch swelling capacity was temperature dependent.

Key words: Cassava, cocoyam, gelatinization, starch, swelling capacity.