Ultrasound-assisted free radical modification on the structural and functional properties of ovalbumin-epigallocatechin gallate (EGCG) conjugates

The influence of ultrasound-assisted free radical modification on the structure and functional properties of ovalbumin-epigallocatechin gallate (OVA-EGCG) conjugates was investigated by experimental measurements and computer simulations. Compared with the traditional free radical condition, the ultrasonic-assisted pro-cessing significantly increased the conjugating efficiency of OVA and EGCG and shortened the conjugating from 24 h to 1 h without affecting the equivalent amount of EGCG conjugating. The sodium dodecyl sulfa-te-polyacrylamide gel electrophoresis and multi-spectroscopy analysis (Fourier transform infrared spectroscopy, intrinsic fluorescence spectroscopy, and UV spectroscopy) indicated that the covalent conjugates could be formed between OVA and EGCG. And modification in the conformation of OVA was induced by EGCG. Furthermore, molecular docking results demonstrated the possession of high-affinity EGCG binding location on OVA, sup-porting and clarifying the experimental results. In addition, the functional properties of OVA including emul-sification (emulsifying activity and emulsion stability) and antioxidant properties (DPPH scavenging capacity and ABTS scavenging capacity) were significantly improved after conjugation with EGCG, especially in ultrasound-assisted conditions. Overall, OVA-EGCG conjugates produced by ultrasound-assisted free radical treatment could be applied as a potential emulsifier and antioxidant, thereby expanding the application of OVA as a dual-functional ingredient.

Automated summary

The influence of ultrasound-assisted free radical modification on the structure and functional properties of OVA-EGCG conjugates was investigated. Ultrasound-assisted processing significantly increased the conjugating efficiency of OVA and EGCG and shortened the conjugating time. Covalent conjugates could be formed between OVA and EGCG, and modification in the conformation of OVA was induced by EGCG. Functional properties of OVA, including emulsification and antioxidant properties, were significantly improved after conjugation with EGCG, especially in ultrasound-assisted conditions.