Effects of Fermentation and Heating on the Functional Properties of Processed Flour from African Oil Bean (Pentaclethra macrophylla benth) Seeds

Abstract

A comparative study was conducted to determine the effects of heat treatment and fermentation on the functional properties of African oil bean (Pentaclethra macrophylla: Benth) seeds. The objective was to determine the nutritional benefits inherent therein, and the possible utilization of this plant food source as a complement in food formulation and improvement. The bean seed was broken to obtain the cotyledon, locally processed by fermentation and heat treatment, after which it was milled to obtain flour from the African oil bean. The control group of day 0 was not subjected to fermentation, but heat-treated and all other experimental groups (Day 1-7) subjected to fermentation and heating. The following selected physio-chemical properties were analyzed for the African oil bean seeds: water absorption capacity, oil absorption capacity and bulk densities were determined; the emulsion capacity and whipping ability were also determined. The oil absorption capacity ranged from 0.66- 1.26 g/ml; water absorption capacity, 0.76-1.32 g/ml; emulsion capacity, 33.33-64.67 g/ml, emulsion stability after one hour, 6.00-63.33 g/ml, bulk density, 0.40-0.49 g/g and whipping ability, 0.00-0.93 g/ml. The processing methods adopted (fermentation and heating) to improve on the functional properties of the African oil bean seeds significantly affected (p<0.05) the bulk density, whipping ability, emulsion stability and Stability after one hour of experimental samples fermented and heat treated (Day 1-7) compared to the Day 0 sample that was only heated while there was, however, no statistical significance recorded for the oil absorption capacity and water absorption capacity in experimental Day 1-7 compared to the control (Day 0). The treatment, demonstrated improved functional properties of the African Oil bean seeds; likely to enhance the palatability of formulated foods. The treatment did not show significant improvement on the oil absorption capacity and water absorption capacity of the bean; however, there was enhanced oil and water functionality.

Key words: Oil bean, Ugba, fermentation, heating