Factors improving dry fractionation of Bambara groundnut aiming at production of protein-rich ingredients with elevated nutritional and technological quality

Abstract

Bambara groundnut is a nutritious African grain legume with potential to be refined into a high-protein ingredient. This work aimed to develop protein-rich ingredients from Bambara via dry processing. Due to Bambara's high fat content, two dry fractionation approaches were developed. In the first one, Bambara was defatted using supercritical CO₂ extraction, milled and air classified producing ingredients with 48 % protein, achieving 74 % of total protein separation efficiency. Without defatting, the efficiency stood at 16.7 %. A second attempt, incorporating a flow aid during air classification, yielded ingredients with 38.2 % protein and protein separation efficiency of 33 %. These protein-rich ingredients exhibited higher protein solubility, total extractability, and water and oil absorption capacities compared to the raw materials. Phytic acid content increased in the protein-rich ingredients, but tannin was significantly reduced. The essential amino acid score of Bambara protein-rich ingredients was higher than 1 and the degree of protein hydrolysis was 31 %.