Functional properties of amylopectin and amylose fractions isolated from bambarra groundnut (Voandzeia subterranean) starch

Abstract

Bambarra groundnut starch was fractionated into amylose and amylopectin fractions, and chemical 
modifications, through oxidation and acetylation, was applied to the amylose fraction. Percentage 
yield of amylose and amylopectin were 75% and 11% respectively. Proximate analysis revealed that 
percentage protein, ash, crude fibre and crude fat were below 1%. Swelling capacity and solubility 
of all the samples increased with increasing temperature. Water and oil absorption capacity 
revealed that hydrophobic tendency was greater than hydrophilic potentials. Gel forming capacity 
increased with increase in concentration of the samples and least gelation concentration was 
minimal in amylopectin fraction. Initial pasting temperature of native amylose reduced from 70oC to 
60oC and 65oC following oxidation and acetylation, respectively. Among the samples, highest 
pasting temperature was recorded in native amylopectin and values for peak viscosity during 
heating (Pv), hot paste viscosity at 95oC (Hv), viscosity after 30 min holding at 95oC (Hv30), cold 
paste viscosity (Cv), set back (SB) and breakdown (BD) were maximal in native amylose.