Impact of Reconstitution Conditions on the Solubility of Faba Bean Protein Isolate

Faba bean protein isolate (FBPI) is emerging as a promising protein ingredient in the food industry. However, a lack of comprehensive scientific understanding of its functional properties, particularly solubility, limits broader application. This study investigated the reconstitution behaviour of FBPI under different conditions. For this purpose, FBPI dispersions (5% w/w protein) were prepared with varying pH (6.8 or 7.5), temperature (15, 40, or 65 °C), duration of stirring (30, 60, or 90 min), stirring intensity (1000 or 1500 rpm), and water hardness (0, 200, or 400 ppm). Low reconstitution temperature resulted in greater particle size and lower solubility, while elevated temperature minimised intermolecular attractions, improving solubility. Higher pH increased the net-negative charge and thus enhanced the repulsion between the proteins, leading to greater solubility. Water hardness was another important parameter, as greater hardness generally resulted in greater particle size and lower solubility, likely due to calcium bridging. The selection of conditions for the hydration of faba bean protein isolate is important to produce high-quality and high-stability suspensions.