Impact of the Covalent Interaction Between Ferulic Acid and Ovalbumin on the Structure and Functional Properties of the Protein

Protein-polyphenol conjugates, formed through chemical modifications, can alter the structure of proteins, thereby enhancing their functional properties and enabling the development of novel ingredients for diverse applications. Despite this potential, the covalent conjugation of ovalbumin (OVA) with ferulic acid (FA) and the determination of their optimal binding ratios have not been previously studied. To address this gap, we investigated the formation of OVA-FA conjugates using an alkaline method and identified an optimal ratio of 0.9 g of FA per g of OVA. The resulting conjugates displayed substantial alterations in the secondary and tertiary structures of OVA, increased hydrophobicity, and a higher molar mass. These structural modifications significantly improved the solubility, emulsification capacity, and foam-forming ability of OVA, while also enhancing its antioxidant activity compared to the unmodified protein. These findings demonstrate the potential of OVA-FA conjugates as multifunctional emulsifiers with antioxidant properties, broadening their applications in the food and nutraceutical industries.