Ultrasound-assisted Maillard reaction of Corynebacterium glutamicum protein: Impact on structure, taste, and plant-based meat applications

The Maillard reaction enhances sensory properties of foods by generating Maillard reaction products (MRPs). A major challenge for consumer acceptance of plant-based meat analogues is their lack of taste. Corynebacterium glutamicum produces various amino acids and proteins; however, its taste attributes were insufficient to substantially enhance the sensory characteristics of plant-based meat analogues. This study aimed to evaluate whether ultrasound-assisted Maillard reactions can improve the taste attributes of C. glutamicum-derived protein (CP). Additionally, the MRPs were applied in plant-based patties (PPs). Optimal Maillard reaction conditions were determined with a CP-saccharide mass ratio of 4:1, ultrasound power of 400 W, reaction time of 45 min, and a temperature of 70 °C. Structure, chemical changes, and taste attributes were assessed in the following samples: (1) CP (control), (2) CP-xylose (CPX), (3) CP-maltodextrin (CPM), (4) MRP of CP-xylose (MCPX), and (5) MRP of CP-maltodextrin (MCPM). The Maillard reaction significantly increased the grafting degree and browning intensity in MCPX and MCPM. Stable structural changes in MRPs were observed in MCPX and MCPM due to increased hydrogen bonds, hydrophobic interactions, and β-sheet content. MCPX and MCPM exhibited improved surface hydrophobicity, protein solubility, and thermal stability compared with other samples. The MRPs displayed reduced sourness and bitterness while enhancing umami taste. Incorporating MCPX and MCPM into PPs resulted in improved taste attributes and texture properties. Overall, this study demonstrated that ultrasound-assisted Maillard reaction induced structural and chemical changes and improved the taste attributes of CP, making it a suitable ingredient for plant-based meat analogues.