Effect of high hydrostatic pressure on in vitro digestibility and techno-functional properties of fava bean (Vicia faba L.) protein

Abstract

The increasing demand for sustainable protein sources has positioned fava beans as a promising alternative; however, their limited techno-functional properties and digestibility restrict broader application within food systems. This study aimed to evaluate the impact of high hydrostatic pressure on the structural, nutritional, and techno-functional properties of fava bean protein isolate under various pressure levels, treatment times, and protein concentrations. Protein dispersions (5–20% w/v) were subjected to pressures ranging from 300 to 600 MPa for up to 9 min, and subsequent changes in protein structure, in vitro digestibility, and functional properties were assessed. Moderate pressures (300–400 MPa) induced partial protein unfolding, thereby increasing the exposure of reactive groups and enhancing enzymatic accessibility, which resulted in improved digestibility, solubility, emulsifying capacity, foaming properties, and water holding capacity. In contrast, higher pressures (≥500 MPa) and extended treatment times promoted protein aggregation, leading to reduced functionality and digestibility. Furthermore, elevated protein concentrations limited structural modifications due to molecular steric hindrance, thereby reducing responsiveness to pressure treatment. These findings demonstrate a biphasic, pressure-dependent behavior whereby controlled structural disruption enhances protein performance, whereas excessive processing induces aggregation and functional decline. Overall, moderate HHP conditions (300–400 MPa) were identified as an effective strategy to enhance the nutritional and techno-functional quality of fava bean protein, offering valuable insights for the development of sustainable plant-based food ingredients.