Comparative studies of the functional and physico-chemical properties of isolated Cassava, Cocoyam and Breadfruit starches

Starches were isolated from cassava, cocoyam and breadfruit by wet milling process. The physicochemical, functional and pasting characteristics of the isolated starches were then examined and compared. Moisture and fat contents varied between 4.91 – 12.94% and 0.90 – 2.20% respectively. Bulk density and pH ranged between 0.64 – 0.68 and 5.53 – 6.15, respectively. Cassava and breadfruit starches exhibited higher water absorption capacity (1.03 and 1.02 g water/g sample, respectively) than breadfruit starch (0.71 g water/g sample) while all the starch samples absorbed almost equal weights of oil. The swelling power was found to increase with increasing temperature with cassava starch exhibiting highest swelling power (2.70 – 5.25) between 60-80°C and breadfruit starch showing the greatest tendency to swell (10.80) at 90°C, respectively. Cassava and breadfruit starches formed stable and firm gels at 8% w/v starch concentrations while cocoyam starch was able to form a gel at 10% starch concentration. The pasting temperatures of 63, 74 and 66°C and peak viscosities of 400, 860 and 960 BU were obtained for cassava, cocoyam and breadfruit starches respectively. The lowest setback viscosity was recorded for cocoyam starch while cassava starch demonstrated the greatest stability towards retrogradation. The starches could find suitable applications in various food products owing to the differences in their physicochemical properties.