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

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. Key words: Bambarra groundnut, amylose, amylopectin, modifications. African Journal of Biotechnology Vol.3(8) 2004: 399-40

Solvent free hydroxylation of the methyl esters of Blighia unijugata seed oil in the presence of cetyltrimethylammonium permanganate

Extraction of oil from the seed of Blighia unijugata gave a yield of 50.82 ± 1.20% using hexane in a soxhlet extractor. The iodine and saponification values were 67.60 ± 0.80 g iodine/100 g and 239.20 ± 1.00 mg KOH/g respectively with C18:1 being the dominant fatty acid. Unsaturated methyl esters of Blighia unijugata which had been previously subjected to urea adduct complexation was used to synthesize methyl 9, 10-dihydroxyoctadecanoate via hydroxylation in the presence of cetyltrimethylammonium permanganate (CTAP). The reaction was monitored and confirmed using FTIR and GC-MS. This study has revealed that oxidation reaction of mono unsaturated bonds using CTAP could be achieved under solvent free condition