Effects of fermentation and boiling on nutrient composition and functional properties of flour and protein isolates from Bambara groundnut (Vigna subterranean)

Abstract

Background: Protein isolates are refined forms of protein containing greater amount of protein with greater digestibility and as such are needed in large quantities in food formulations to help in alleviating protein energy malnutrition.

Objective: To produce protein isolates from boiled and fermented bambara groundnut flour. Methods: Bambara groundnut seeds were soaked (48 hr), dehulled, oven dried (40^oC for 8 hr) and dry milled into flour (fermented bambara flour). Also, the boiled bamabara flour was produced by boiling the seeds (100^oC for 40 mins), dehulled, washed, sun dried (48 hr) and dry milled into flour. The protein isolates from the flour were extracted using standard methods. The nutrient composition and functional properties were also determined using standard methods. Data obtained were subjected to analysis of variance and results were expressed as means + standard deviation.

Results: The protein contents of the isolates from fermented and boiled bambara groundnut flour (82.15 - 83.10%) were found to be higher than the protein contents of the fermented and boiled bambara flour samples (18.77 and 24.40%, respectively). The oil and water absorption capacities of the protein isolates from boiled and fermented bambara flour (101.50-105.50% and 221-223.5%, respectively) were higher compared to the flour samples (72.05-76.15.00% and 162.05-167.50%, respectively).

Conclusion: The protein isolates from bambara groundnut flour had 82.15% and 83.10%, respectively could be exploited for use in different food formulations that might be used for the management of protein energy malnutrition.

Keywords: Flour, protein isolate, bambara groundnut