High internal phase Pickering emulsion gel stabilized by whey protein isolate/rutin/guar gum complex for 3D bio-inks

Recently, 3D bio-printing technology has been interested in the food tech fields, such as 3D bio-inks of alternative food and 3D scaffolds of cultured meat. However, previous researches on 3D bio-inks have used protein and polysaccharide as the main sources. The study for 3D bio-inks containing lipid to have 3D printability has been required. Therefore, the protein/polyphenol/polysaccharide complex was applied as a stabilizer to the high internal phase Pickering emulsion gel (HIPE) to improve 3D printability. The aims of this study were 1) to prepare a ternary complex by linking whey protein isolate/rutin/guar gum (WPI/RU/GG), 2) to develop the HIPE stabilized by WPI/RU/GG, and 3) to analyze the correlation between the chemical, morphological, and rheological properties of HIPE and their 3D printability. The successful synthesis of the ternary complex was identified by the results of fluorescence, FT-IR, and XRD spectra with considerable changes in characteristic peaks of the ternary complex. The HIPE stabilized by WPI/RU/GG, O/W emulsion exhibited stable self-standing properties for 3 weeks. These HIPE stabilized by WPI/RU/GG demonstrated a smaller and denser droplet size compared to those stabilized by WPI alone. Rheological analysis indicated a significant increase in storage modulus (G') and loss modulus (G″) due to the incorporation of WPI with RU and GG. Additionally, the creep test and three interval thixotropic recovery test showed a high recovery property, contributing to the stable 3D printability of HIPE stabilized by WPI/RU/GG. Therefore, these results suggest that HIPE stabilized by WPI/RU/GG can be unique candidates for 3D bio-inks with controlling fat in the 3D bioprinting industry.