Iron-caseinglycomacropeptide complexes: Characterization and application in beverages

Area of Science:

• Food Science and Technology
• Biochemistry
• Nutritional Science

Background:

• Iron deficiency is a global health issue, often addressed by fortifying foods.
• Traditional iron supplements can have poor bioavailability and sensory acceptance.
• Complexing iron with organic compounds like casein macropeptide (CMP) offers a potential solution.

Purpose of the Study:

• To optimize the formation conditions of iron-CMP complexes.
• To elucidate the molecular interactions between CMP and iron ions.
• To assess the stability and applicability of the Fe/CMP complex for food fortification.

Main Methods:

• Optimization of Fe/CMP complex formation conditions.
• Fourier-transform infrared (FTIR) spectroscopy to analyze structural changes.
• Stability testing across a pH range (2.0-6.5).
• Application testing in a commercial beverage.

Main Results:

• CMP binds ferrous iron at a 1:1.5 M ratio, forming a stable tetrameric complex.
• Iron binding alters CMP's secondary structure, with binding sites involving Glu, Asp, and sialic acid residues.
• The Fe/CMP complex demonstrates stability across a broad pH range and maintains beverage color during storage.

Conclusions:

• The Fe/CMP complex is stable and suitable for incorporation into food and beverages.
• CMP shows potential as an effective peptide for iron fortification applications.
• A binding model for CMP and iron was proposed, aiding future research.