Effect of Shear and pH on Heat-Induced Changes in Faba Bean Proteins

Commercially relevant processing conditions, including protein concentration, pH and shearing and their impact on the solubility, heat stability, and secondary structure of faba bean proteins (FBPIs), were studied. Most of the examined properties, including protein solubility and heat stability, were due to the simultaneous effects of pH and concentration. The shearing rate played a crucial role in determining the heat stability of FBPI during thermal processing through protein molecular activities, such as inter- and/or intramolecular force interactions. Under the heat treatment conditions (temperature of 95 °C and time of 30 min), the shearing rate of 1000 s^-1 enhanced the heat stability, compared to 100 s^-1. Meanwhile, concentration and pH shift contributed to the conformation of various protein structures of faba bean protein isolates. This study revealed that these structural changes involve the unfolding of the protein's native tertiary structure, which likely exposes hydrophobic and sulfhydryl (-SH) groups, ultimately leading to protein aggregation. It also provided a comprehensive understanding of faba bean protein functionality by studying various interactions of FBPI proteins under thermal processing systems.