关键词: 迷迭香酸, 蛋清蛋白, 自由基法

Abstract: Egg white protein (EWP) is a nutrient-rich protein. This study aims to enhance the functional properties of EWP and reduce its antigenicity by covalently coupling with rosmarinic acid (RA) via free radical method. The SDS-PAGE profile and RA binding equivalence confirmed successful synthesis of EWP-RA conjugates. Multispectral analysis, including FTIR, CD, fluorescence, and UV absorption spectroscopy, demonstrated significant structural alterations in EWP-RA compared to EWP. These structural changes resulted in modifications to the functional properties of EWP, including antioxidant capacity and emulsifying properties. The DPPH and ABTS radical scavenge capacities of EWP-RA 0.2 were 58.59 % and 72.08 %, respectively, significantly higher than EWP alone (DPPH: 15.21 %; ABTS: 49.09 %). ELISA results showed that EWP-RA had markedly lower binding capacities to IgG and IgE antibodies from egg allergy sufferers, showed a reduced potential for antigen binding. Furthermore, EWP-RA exhibited improved emulsifiability, with EWP-RA 0.02 showing the best emulsifying properties, evidenced by emulsifying activity index (EAI: 1.21 m2/g) and emulsifying stability index (ESI: 64.20 min). This study provides a methodological and theoretical foundation for the covalent modification of EWP with polyphenols using a free radical approach.

Key words: Rosmarinic acid, Egg white protein, Free radical method