Optimizing 3D Food Printing inks: The Impact of Polysaccharides on Camellia Seed Protein Emulsion Gels

Emulsion gels with unique structure and mechanical properties have great potential in 3D food printing applications. In this study, the rheological properties and 3D printing characteristics of Camellia seed protein (CSP) emulsion gels were investigated by incorporating three different polysaccharides: anionic xanthan gum (XG), highly branched neutral guar gum (GG), and lowly branched neutral locust bean gum (LBG). The influence of the polysaccharide type on the printability, rheological properties, microstructure, and water distribution properties of inks were analyzed. Results indicated that CSP-XG ink exhibited superior dimensional accuracy, excellent self-supporting capability, and a smooth surface with minimal flaws. While CSP-GG ink presented a rougher surface texture and structural collapse. Rheological analysis demonstrated that the addition of polysaccharides significantly enhanced the mechanical properties of the paste, with CSP-XG ink exhibiting the highest gel strength of 656.8 Pa, compared to CSP emulsion gel (491.2 Pa), providing the highest hardness in the 3D printed products. Microstructure observations and Fourier transform infrared (FTIR) analysis suggested that the interactions between CSP and XG were stronger than those between CSP and GG or LBG. Low-field nuclear magnetic resonance (LF-NMR) results revealed that XG reduced water mobility and enhanced gel density. While GG primarily relied on its high viscosity to limit water mobility. The presence of LBG enhanced the water-holding capacity due to its long chain structure. This study highlighted the potential for further development of CSP emulsion gels as 3D printing inks, offering new insights into optimizing food ink formulations for improved stability and performance.