TD-NMR Structural Profiling of Meat and Plant-Based Meat Analog Burgers

The functional properties of food are closely linked to its atomic, molecular, and microstructural characteristics. This study evaluates the potential of time-domain nuclear magnetic resonance (TD-NMR) relaxometry as a non-destructive technique for profiling the internal microstructure of Soy-based plant-based meat analogs (PBMA) compared to Angus beef burgers. TD-NMR results were supported by measurements of water content, water release, and morphological analysis using visual and confocal microscopy. Microscopy revealed clear structural differences: Soy-PBMA burgers exhibited a gel-like, porous matrix, while Angus beef burgers showed compact, fibrous bundles characteristic of natural muscle tissue. Moisture analysis indicated lower total water content in Soy burgers, while water release tests demonstrated higher water-holding capacity in Angus burgers, suggesting stronger protein-water interactions. TD-NMR relaxation data reflected these structural distinctions. T₁ recovery times were longer in Angus burgers, while T₂ relaxation times were shorter and more narrowly distributed, consistent with tightly packed myofibrillar proteins. In contrast, Soy-PBMA burgers exhibited broader T₂ distributions, reflecting a looser, more porous plant-protein matrix. One-dimensional (1D) and two-dimensional (2D) T₁-T₂ spectral fingerprinting further highlighted differences in proton relaxation behavior, particularly between the myofibrillar proteins of meat and the globular proteins of plant-based formulations. These findings confirm TD-NMR relaxometry as a rapid, reliable, and non-destructive method for differentiating the internal structure of meat and plant-based products. This approach offers valuable insights for product development, quality assurance, and the design of next-generation plant-based meat alternatives.