Effect of Fermentation on Antinutritional Factors and Functional Properties of Fermented Bambara Nut Flour

Abstract

Bambara nut (Vigna subterrenean) is a cheap source of leguminous protein that can be a good substitute for relatively expensive animal protein to reduce malnutrition. Despite its potentials, it remains underutilized owing in part to long cooking time, presence of antinutritional factors and drudgery in dehulling. In this regard, this study determined effects of fermentation on antinutritional and functional properties of bambara nut flour. Bambara nut was procured from local market in Abeokuta while pure culture of Rhizopus oligosporous was obtained at the Department of Food Science and Engineering, Ladoke Akintola University of Technology. Bambara nut was fermented for 12, 24, 36, 48, 60 and 72h at 32ºC and dried in oven (55ºC/24 h). The antinutritional (tannin, oxalate, phytate, and trypsin inhibitor) and functional properties (water-absorption-capacity, solubility and swelling power) of the composite flour were determined. The data obtained were subjected to descriptive and inferential statistics and significance established at P=.05. Respective range of values for tannin, oxalate, phytate and trypsin inhibitor were 0.08 - 0.32, 0.72 - 1.49, 0.15 - 3.64 and 0.42 - 3.25 mg/g, respectively. Water absorption capacity, solubility and swelling power ranged from 8.67 - 11.04, 52.59 - 53.07, 9.20 - 10.16 and 9.14 9.16%,  respectively. The fermentation process reduced the antinutritional factors and increased the protein content.