Proximate composition and selected functional properties of fermented and unfermented African oil bean (Pentaclethra macrophylla) seed flour

Flour samples were prepared from fermented and unfermented African oil bean (Pentaclethra macrophylla) seeds (AOBS). The flour samples were evaluated for proximate composition and certain functional properties. The influence of defatting on these properties was also determined. Fermentation significantly increased (p < 0.05) the protein and decreased the crude fiber, ash, fat and carbohydrate contents of the AOBS flours. The nitrogen solubility of both fermented and unfermented flours was pH dependent with minimum and maximum solubility at pH 4.0 and pH 8.0, respectively, and with increased nitrogen solubility in the fermented sample. The fermented and unfermented flour samples had least gelation concentrations of 14 and 16% (w/v), respectively. The water absorption capacity and foam capacities of the fermented flour were 36 and 34%, respectively, over the unfermented seed flour. On the other hand, fermentation decreased the fat absorption capacity, emulsion activity and emulsion and foam stabilities. Fermentation decreased (p < 0.05) the bulk density of AOBS flour by 15%. Defatting improved all the functional properties evaluated except emulsion activity. These results indicate potential food uses of fermented and unfermented AOBS flour samples as protein supplements in diets and as functional ingredients in formulated foods.