Improvement in 3D printability, rheological and mechanical properties of pea protein gels prepared by plasma activated microbubble water

Three-dimensional (3D) food printing is one of the emerging processing technologies that enables the construction of complex food structures and customization. Although various food ingredients have been explored for their 3D printability, pea protein is among the plant proteins that have not been studied extensively on its 3D printability, owing to its native inability to hold shape and structure following extrusion. This study investigated the effect of plasma activated microbubble (PAMB) treatment on the thermal gelation and 3D printability of pea protein isolate (PPI). PAMB treatments with different combinations of discharge gases (80% argon and 20% air, 90% argon and 10% air, 100% argon, and 100% air) were applied to prepare PPI suspensions. These suspensions were then heated at 85 degrees C for 30 and 60 min, followed by immediate cooling to prepare PPI gels. The viscoelastic measurements and mechanical properties of PPI gels indicated that this combined application was suitable for 3D printing, with a notable increase in storage modulus (G ' ), loss modulus (G " ) and compressive stress in PPIPAMB gels. The 3D printed PPI gels prepared using PAMB treatment exhibited better structure retention, resistance to deformation, and stability during storage. The treatment using PAMB prepared by the combination of argon and air, i.e., 80% argon and 20% air and 90% argon and 10% air, resulted in PPI gels with better rheological properties, mechanical stability, and 3D printability. Freeze drying was investigated as a possible post -3D printing processing operation to enhance the shelf life and storage stability of 3D printed PPI gels. The moisture content, water activity, and textural properties of the freeze-dried 3D printed PPI were investigated.