Characterization and mechanism of thermally induced tea polyphenols and egg white proteins gel system and its 3D printing

In this study, the effect of tea polyphenols (TP) on the properties of thermally induced egg white protein (EWP) gel system was investigated by rheological, particle size, ζ potential, fluorescence spectroscopy, FT-IR, DSC, LF-NMR, SEM, and the suitability of EWP-TP for 3D food printing technology was assessed. The results showed that with the addition of TP, the interaction of TP with EWP led to fluorescence quenching and a blue shift of the maximum emission wavelength. The decrease in the polarity of the microenvironment around the EWP increased the hydrophobicity and altered the peptide chain structure with the addition of TP. Compared with the EWP gel system, the structure of the EWP-TP gel system had higher thermal stability and lower water content, and the microstructure of the network was more homogeneous, dense and smooth. The addition of TP significantly improved the stability of the EWP-TP gel system, the absolute value of the potential of the EWP gel system was 16.73 ± 0.91 nm, which was significantly lower than the EWP-TP gel system (P < 0.05). Besides, the 3D printing gel system prepared by EWP-TP and polysaccharide had the smoothest printing lines, more stable structure, and the best printing effect at the 0.12 g TP addition.