Effect of induction mode on 3D printing characteristics of whey protein isolate emulsion gel

This study mainly explored the influence of different induction modes such as NaCl and Transglutaminase on the 3D printing characteristics of whey protein isolate emulsion gel. The properties of gel were characterized from rheological properties, microstructure, Fourier transform infrared spectroscopy, thermal stability and other aspects, and the relationship between 3D printing molding characteristics of gel and its applicability as a diet for dysphagia was discussed. Strain and frequency sweep showed that the addition of NaCl made gel difficult to be extruded during printing, while the addition of TG could get the opposite result. From a microscopic point of view, too high concentration of NaCl would lead to the disordered aggregation of proteins, which would reduce the structural strength of gel and make the water binding unstable. The addition of TG made the gel network have an orderly three-dimensional structure, making the water binding more stable. Both NaCl and TG can cause the secondary structure of protein to be more orderly and the thermal stability to be reduced, and the texture characteristics such as hardness, resilence, springiness, gumminess and chewiness to be reduced. During 3D printing of emulsion gel containing high concentration of NaCl, unsmooth extrusion filaments and pattern collapse occurred. TG can significantly improve the accuracy of 3D printing products. This study provided a basis for the application of whey protein isolate emulsion gel in 3D printing. [Display omitted] •Whey protein isolate emulsion gel (WPI-EG) was prepared by three induction modes.•Both NaCl and Transglutaminase (TG) led to order of protein secondary structure.•Both NaCl and TG changed the rheological properties and microstructure of WPI-EG.•The addition of high concentration NaCl was not conducive to 3D printing of WPI-EG.•TG improved the 3D printing suitability of WPI-EG.