Comparative analysis of 3D printability and rheological properties of surimi gels via LF-NMR and dielectric characteristics

The rheological properties of raw materials as 3D printing inks play a vital role in their printability and quality. This work was aimed to evaluate the potential of low field nuclear magnetic resonance (LF-NMR) and dielectric characteristics (at 915 and 2450 MHz) to predict the rheological properties and estimate the printability of surimi gels at different NaCl and water concentrations. Hierarchical cluster analysis of rheological parameters showed four groups of surimi gels, which were described as difficult extrusion, good extrusion and self-supporting, good extrusion but poor self-supporting, and difficult formation. Comparison of two monitoring techniques, discriminant analysis based on LF-NMR showed a higher classification accuracy of printability in samples, and partial least squares regression (PLSR) models using LF-NMR for predicting main rheological properties had better predictive accuracy and robustness. Thus, the study indicated that LF-NMR has a great potential in predicting rheological properties and estimating the printability of surimi gels.