Effect of enzymatic cross-linking of naringenin-loaded 13-casein micelles on their release properties and fate in in vitro digestion

The microbial transglutaminase (mTG) was used to improve the stability of the naringenin-loaded 13-casein micelles (CNMs). The formation of cross-linked CNMs was confirmed by SDS-PAGE electrophoresis, showing a decrease in monomeric 13-CN levels with increasing crosslinking time. Dynamic light scattering (DLS) showed that after crosslinking the particle size distribution did not change upon dilution, suggesting occurrence of intracrosslinking. Fluorescence spectroscopy and circular dichroism (CD) showed that crosslinking induced only minor changes in the structure. Finally, release of naringenin in buffer at pH 7.4 demonstrated a slower release from the cross-linked micelles compared to the untreated micelles. In addition, the cross-linked micelles exhibited a partial resistance to pepsin enzyme. We conclude that crosslinking with mTG is a suitable method to modulate naringenin release kinetics from 13-CN micelles and improves the potential of these micelles as delivery systems targeted to the small intestine.

Automated summary

The study demonstrates that crosslinking with microbial transglutaminase (mTG) improves the stability and slow release effect of naringenin-loaded 13-casein micelles (CNMs). Dynamic light scattering shows that the micelles are not easily diluted after crosslinking, while fluorescence spectroscopy and circular dichroism show that crosslinking only has minimal impact on the structure.