Epsilon Archive for Student Projects

Abstract

With the rapid growth of the global population and the increasing demand for food, transitioning toward plant-based proteins is vital for establishing sustainable food systems, reducing reliance on animal agriculture, and balancing protein production. Legumes represent one of the most promising plant-based protein sources for food industry applications; however, they have received comparatively less attention than conventional sources such as soy and wheat. Therefore, optimizing extraction yields and understanding genotype-specific functional properties are essential steps toward overcoming the technical challenges associated with their industrial utilization.

This study aimed to optimize the alkaline extraction–isoelectric precipitation (AE–IEP) protocol using the ‘Gloria’ faba bean cultivar, followed by a comprehensive evaluation and comparison of the structural and techno-functional properties of six distinct genotypes. The optimization phase investigated the effects of flour defatting, pH variations during extraction, and the application of double centrifugation on the residual pellet to enhance protein recovery. The results revealed that combining defatting with double centrifugation increased the protein extraction yield of the Gloria cultivar from 32.4% to 57.3%. Consequently, the optimal processing parameters were established as defatting combined with double centrifugation at an alkaline extraction pH of 8.0, isoelectric precipitation at pH 4.5, and final neutralization to pH 7.0, while avoiding more extreme alkaline conditions that may promote conformational changes and protein denaturation.

Applying this optimized process to all six genotypes produced protein isolates, among which SLU10 achieved the highest protein recovery yield (69.5%). FTIR spectroscopy indicated a predominant β-sheet secondary structure in the protein isolates, while SE-HPLC analysis revealed differences in chromatographic profiles among the samples, with the B19 protein isolate showing a higher relative signal in the earlier 9.45–12.55 min retention-time region. Regarding techno-functional performance, SLU10 and Tiffany protein isolates exhibited the highest foaming capacity (50%), whereas the B19 protein isolate showed the highest emulsifying activity, achieving the highest Emulsifying Activity Index (EAI). The developed faba bean protein-based mayonnaise prototype was also evaluated by 12 untrained panelists, who generally rated its sensory attributes positively, indicating promising initial acceptability.

Overall, this research highlights differences in functional behavior among the investigated faba bean samples, suggesting that raw material selection for food formulations should be targeted according to specific application requirements.