Impact of transglutaminase on structural and rheological properties of pea protein-cornmeal-wheat gluten blends for meat analogue production

Transglutaminase (TGase) is commonly used in plant protein modification to improve the quality of meat analogues. Pea protein, cornmeal, and wheat gluten were chosen for the preparation of pea protein-cornmeal-wheat gluten-meat analogue (PCWMA) due to their widespread availability and affordable price, while PCWMA fibrous structure differed slightly from that of real meat. Results showed that the addition of TGase enhanced the covalent cross-linking of protein, and also hardness and fibrous degree of extrudates were significantly improved. However, it was detrimental to the formation of fibrous structure when the amount of TGase addition exceeded 0.3%. Protein rearrangement during extrusion showed a dense structure in the SEM images. TGase addition contributed to the increase of β-sheet and water-holding capacity of the extrudates, and decrease of β-turn, tryptophan residues and oil-holding capacity, indicating that the stability of protein structure was related to hydrogen bond, disulfide bond and hydrophobic interaction. Furthermore, the apparent viscosity and denaturation degree were highest while 0.2% TGase was added. The ability to optimize the use of TGase can lead to better quality meat analogues, meeting the growing demand for alternative protein sources in the food market and providing more options for consumers who are seeking plant-based or reduced-meat diets.