Abstract

The physicochemical properties of bambarra groundnut starch (BBS) and cassava starch (CS) were blended at different ratios (70BBS/30CS, 50BBS/50CS and 30BBS/70CS) and investigated. The minor components (lipids and proteins) of the starch granules were lowest for CS and highest for the blended starches. Apparent amylose (AAM) content of the starch blends was additive of their individual components. CS had the lowest AAM value (20.20%) and the 70BBS/30CS blend the highest value (41.53%). Swelling power (SP) was highest for CS at higher temperature and the SP of the blended starches was additive at 75 and 95°C. The solubility of the blended starches was additive at lower temperatures (55 and 65°C). The bulk density and dispersibility were non-additive and pH of the blends was additive of their individual components. With the exception of peak and breakdown viscosities, all the pasting parameters of the blends were additive of their individual components. CS had the highest peak (553.75 RVU) and breakdown (391.17 RVU) viscosities, but the lowest trough (162.58 RVU), final (274.63 RVU) and setback (112.05 RVU) viscosities. The 50BBS/50CS blend had the lowest breakdown viscosity (149.59 RVU) for thermal stability. Overall results indicate that blending native starches from different botanical sources improves their properties.

Key words: Bambara groundnut starch, wheat starch, control starches, pasting, dispersibility.