Investigation on 3D printing ability of soybean protein isolate gels and correlations with their rheological and textural properties via LF-NMR spectroscopic characteristics

Soy protein isolate (SPI) with/without xanthan gum (at 0.5 g/30 g of SPI) and NaCl solution at different concentrations (1, 2 or 3 g in 100 mL of distilled water) was assessed for its 3D printing ability; the texture of the printed gels was also determined. To allow a priori determination of the printing ability and hence the ability to reduce the number of tedious printing experiments, correlations between rheological and textural properties as well as LF-NMR spectroscopic characteristics of the gels and their 3D printing ability were investigated. SPI gel with xanthan gum and NaCl solution at 1 g/100 mL could be successfully printed and better matched the designed 3D models than the gels of other formulations. Strong correlations between LF-NMR major peak relaxation time (T2 (MP)) and peak area (A22) with the rheological properties, which were in turn related to the printing ability, were noted.