Ultrasound and enzyme assisted preparation of novel lactoferrin-cereal phenolic acid conjugates: structural, physicochemical and functional properties

Li Y 1 , Dong L 1 , Liu Y 1 , Chen Q 1 , Wu Z 1 , Liu L 2 Show all authors , Farag MA 3 , Liu L 4

Affiliations 

  • 1 State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Animal Protein Deep Processing Technology of Zhejiang, Zhejiang-Malaysia Joint Research Laboratory for Agricultural Product Processing and Nutrition, School of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang, PR China
  • 2 Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln 68588, NE, USA
  • 3 College of Pharmacy, Cairo University, Alexander von Humboldt Fellow, Egypt
  • 4 State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Animal Protein Deep Processing Technology of Zhejiang, Zhejiang-Malaysia Joint Research Laboratory for Agricultural Product Processing and Nutrition, School of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, Zhejiang, PR China. Electronic address: lianliang626@hotmail.com
Food Chem, 2024 Mar 01;435:137572.
PMID: 37778268 DOI: 10.1016/j.foodchem.2023.137572

Abstract

The effects of covalent binding of protocatechuic acid (PA) and gallic acid (GA) to lactoferrin (LF) on the structure, functional, and antioxidant properties of the protein conjugate were investigated. These protein-phenolic conjugates were produced by laccase cross-linking and ultrasound-assisted free radical grafting, which were characterized using turbidity, particle size, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analyses. Structural changes in conjugates were monitored by endogenous fluorescence spectroscopy, fourier transform infrared spectroscopy (FTIR), and circular dichroism (CD). The antioxidant capacities and pH stability were determined using DPPH, ABTS, FRAP, and potentiometric analysis. The enzymatic cross-linking and free radical grafting yielded LF-PA/GA conjugates with altered hydrodynamic diameter and zeta-potential. Spectroscopic and chromatographic analyses revealed that binding to PA/GA altered the molecular structure of LF, with a decrease in LF isoelectric point post binding to PA/GA, without affecting antioxidant activities. In conclusion, LF-PA/GA conjugates present potential applications in the food industry.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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