High moisture extrusion of meat analogues using mung bean (Vigna radiata L.) protein and flour blends: investigations on morphology, texture and rheology

High moisture meat analogues (HMMA) from the blends of mung bean protein isolate (MPI) and mung bean flour (MF) at different MF contents (10%, 20% and 30%) were prepared using high moisture extrusion (HME) and die texturisation. Pure MPI could not be extruded and texturised. Therefore, MF was added to improve the extrudability and to assist in the texturisation of HMMA. Rheological analysis performed under a range of simulated conditions in the cooling die demonstrated the decrease in both storage and loss moduli of the blend systems as compared to pure MPI, which explained the flow capability and extrudability of the blends during die texturisation. The effect of blend compositions on morphology and texture of the extrudates was investigated. All blend extrudates showed an anisotropic layer structure with a less pronounced velocity profile with increasing MF content. The microstructure of these extrudates revealed the presence of a multiphase system of the remaining MF fragments dispersed in a continuous protein matrix, thereby facilitating phase separation, loosening the protein structure and decreasing textural properties of HMMA as MF content increased. The results demonstrate that the blend of MPI and MF is a promising ingredient to prepare mung bean-based HMMA with the customised texture properties.