Na+- and Ca2+-mediated mung bean protein-wheat gluten low-moisture extruded products: structural and techno-functional characteristics.

Background: Sodium chloride (NaCl) and calcium chloride (CaCl₂) are commonly used salts in food processing, known to affect protein interactions and structural properties. However, their specific impact on low-moisture mung bean protein-wheat gluten (LMW) products remains unclear.

Results: This study explored the impact of NaCl and CaCl₂ (0%, 0.5%, 1%, 1.5%, 2% and 2.5%) on the protein structure and functional properties of LMW products. The findings revealed that the incorporation of 1% NaCl and 0.5% CaCl₂ significantly enhanced the rehydration rate, expansion rate, oil retention capacity and cooking yield of LMW, while simultaneously reducing its hardness and chewiness post-rehydration, thereby improving its edibility. The incorporation of NaCl and CaCl₂ reduced electrostatic repulsion and protein solubility, and the higher charge density of Ca²⁺ compared to Na⁺ greatly enhanced the structural stability and mechanical properties of LMW. However, excessive concentrations negatively affected LMW attributes.

Conclusion: The results provide valuable insights into the role of NaCl and CaCl₂ in modifying the structure and functionality of low-moisture extruded protein products. Optimizing salt concentrations can enhance product quality while maintaining a balance between structural stability and textural properties. These findings contribute to the development of low-salt, plant-based meat analogues with increased consumer appeal. © 2025 Society of Chemical Industry.