Grafting phenolics onto milk protein via conjugated polymerization for delivery of multiple functionalities: Synthesis and characterization

Ahmed A Abd El-Maksoud; Sampson Anankanbil; Ye Zhou; Ismail H Abd El-Ghany; Hossam S El-Beltagi; Chiranjib Banerjee; Steen V Petersen; Zheng Guo

doi:10.1016/j.foodchem.2019.125298

Grafting phenolics onto milk protein via conjugated polymerization for delivery of multiple functionalities: Synthesis and characterization

Food Chem. 2019 Dec 15:301:125298. doi: 10.1016/j.foodchem.2019.125298. Epub 2019 Jul 30.

Authors

Ahmed A Abd El-Maksoud¹, Sampson Anankanbil², Ye Zhou³, Ismail H Abd El-Ghany⁴, Hossam S El-Beltagi⁵, Chiranjib Banerjee⁶, Steen V Petersen⁷, Zheng Guo⁸

Affiliations

¹ Department of Dairy Science, Faculty of Agriculture, Cairo University, Giza 12613, Egypt; Department of Engineering, Aarhus University, Gustav Wieds vej 10, Aarhus 8000, Denmark. Electronic address: ahmed_ali@cu.edu.eg.
² Department of Engineering, Aarhus University, Gustav Wieds vej 10, Aarhus 8000, Denmark. Electronic address: sampsonanankanbil@eng.au.dk.
³ Department of Engineering, Aarhus University, Gustav Wieds vej 10, Aarhus 8000, Denmark. Electronic address: yezhou@eng.au.dk.
⁴ Department of Dairy Science, Faculty of Agriculture, Cairo University, Giza 12613, Egypt.
⁵ Agricultural Biotechnology Department, College of Agriculture and Food Sciences, King Faisal University, Alhassa 31982, Saudi Arabia; Biochemistry Department, Faculty of Agriculture, Cairo University, Giza 12613, Egypt. Electronic address: helbeltagi@kfu.edu.sa.
⁶ Department of Chemistry, Aarhus University, Gustav Wieds vej 14, Aarhus 8000, Denmark. Electronic address: banerjee@chem.au.dk.
⁷ Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, Aarhus 8000, Denmark. Electronic address: svp@biomed.au.dk.
⁸ Department of Engineering, Aarhus University, Gustav Wieds vej 10, Aarhus 8000, Denmark. Electronic address: guo@eng.au.dk.

PMID: 31387044
DOI: 10.1016/j.foodchem.2019.125298

Abstract

A synthetic scenario for functionalization of β-lactoglobulin (βLg) with polymeric units containing caffeic acid (βLg-polyCA) was developed; and all intermediates and final products were structurally confirmed using nuclear magnetic resonance spectroscopy, matrix assisted laser desorption ionization time-of-flight mass spectrometry, and physico-chemically characterized using differential scanning calorimetry and circular dichroism. The antioxidant properties and emulsion stability of βLg, βLg-CA conjugate and βLg-polyCA based systems containing high percentage of fish oil (50%) were evaluated; and βLg-polyCA presented the highest antioxidant and free radical-scavenging activity based on DPPH, ABTS and HS scavenging assays (92.4, 87.92 and 67.35% respectively). Thiobarbituric acid (TBARS) test demonstrated that compared to native βLg, βLg-polyCA afford up 4-5 fold of inhibition of oxidative rancidity and displayed drastic secondary structure changes. Compared to native βLg based emulsions, βLg-polyCA had larger oil droplet sizes, stronger negative zeta potentials (-69.9 mv), narrower size distributions (PDI: 0.22) and less creaming index.

Keywords: Antioxidant; Emulsion system; Polymer grafting; Polymerization; Protein-phenolic conjugate; β-Lactoglobulin.

MeSH terms

Antioxidants / chemistry
Antioxidants / pharmacology*
Caffeic Acids / chemistry
Calorimetry, Differential Scanning
Circular Dichroism
Dynamic Light Scattering
Emulsions / chemistry*
Fish Oils / chemistry*
Lactoglobulins / chemistry*
Lipid Peroxidation
Magnetic Resonance Spectroscopy
Oxidation-Reduction
Phenols / chemistry*
Polymerization
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Substances

Antioxidants
Caffeic Acids
Emulsions
Fish Oils
Lactoglobulins
Phenols
caffeic acid