Mechanistic insights into protein structure, nutritional quality and physical attributes of faba bean protein-based...

Understanding extrusion-induced protein transformations is critical for improving the nutritional and textural properties of faba bean protein (FBP)-based high-moisture meat analogues (HMMAs). This study examined the impact of barrel temperature (125-145 °C) and feed moisture (50-58%) on the protein structure, nutritional quality, and physical attributes of FBP-based HMMAs. Extrusion reduced protein solubility of FBP from 33% to 5-7%, primarily due to formation of disulfide bonds. A significant negative (r = -0.88, p < 0.01) correlation was identified between solubility and intermolecular β-sheets. Increasing feed moisture from 50% to 58% at 145 °C helped retain sulfur-containing amino acids, thereby improving the in vitro protein digestibility-corrected amino acid score from 62.6% to 66.2%. Higher feed moisture also produced softer, less chewy HMMAs. Overall, the structural modifications of FBP during HMMA production are governed by complex molecular interactions, and adjusting feed moisture provides a viable strategy to enhance protein nutritional quality.