Construction, stability and photodynamic germicidal efficacy of curcumin nanoemulsion stabilised with Maillard conjugate of Wpi‐Rha.

Curcumin has excellent antioxidant and antibacterial properties. The poor solubility and easy degradation limit its application. The present investigation was aimed to prepare curcumin nanoemulsions (Cur‐Ne), employing homogeneous and ultrasonication for the encapsulation of curcumin to overcome these problems. Cur‐Ne stabilised using whey protein isolate and rhamnose conjugate (Wpi‐Rha) was prepared by Maillard reaction. Furthermore, the processing (i.e. ionic strength, heat and freeze‐thaw) and storage stability of Cur‐Ne were evaluated. Moreover, the bactericidal capacity of Cur‐Ne combined with photodynamic therapy (PDT) technology was estimated. Cur‐Ne was prepared successfully with the droplet size of 185.97 ± 6.65 nm, polydispersity index (PDI) of 0.21 ± 0.01, zeta potential of −35.17 ± 0.15mV and entrapment efficiency of 97.0 ± 0.07%. Meanwhile, Cur‐Ne was stable at different storage and processing conditions. In addition, the DPPH and ABTS radical scavenging rates of Cur‐Ne were 84.86 ± 0.24% and 99.63 ± 0.48%, respectively. At the adding amount of 5 μL of Cur‐Ne, the Cur‐Ne could deactivate the Escherichia coli and Staphylococcus aureus with the antibacterial rate of 99.05 ± 0.13% and 99.11 ± 0.18%, respectively. Curcumin loaded in nanoemulsion and combined with PDT provide new ideas for food storage and sterilisation. [ABSTRACT FROM AUTHOR]