Structural changes and in vitro bioaccessibility of CPP-febisgly complexes: Dependence on iron load

Area of Science:

• Nutritional Science
• Biochemistry
• Materials Science

Background:

• Iron deficiency anemia remains a global health concern.
• Conventional iron supplements often suffer from poor bioavailability and gastrointestinal side effects.
• Casein phosphopeptides (CPP) are known to enhance mineral absorption.

Purpose of the Study:

• To investigate the synergistic effects of CPP and ferrous bisglycinate (FebisGly) on iron supplementation.
• To evaluate the impact of CPP on FebisGly's in vitro bioaccessibility, structural properties, and antioxidant activity.
• To explore the role of CPP in overcoming iron absorption inhibitors.

Main Methods:

• In vitro assessment of iron bioaccessibility at varying CPP:FebisGly ratios (1:20, 1:10, 1:5 w/w).
• Analysis of structural changes using techniques like circular dichroism (CD) spectroscopy.
• Particle size distribution (PSD) and rheological analyses to assess chelated iron formation.
• Evaluation of antioxidant activity and competition with absorption inhibitors (phytic acid, tannic acid, cellulose).

Main Results:

• CPP enhanced FebisGly bioaccessibility by up to 68.72%.
• CPP increased β-sheet content, indicating stable secondary structure formation and chelated iron.
• Uniform PSD and enhanced viscoelasticity were observed, suggesting improved iron complex stability.
• CPP prolonged gastric emptying time, reducing gastric irritation and outcompeted absorption inhibitors for iron.

Conclusions:

• CPP significantly enhances the bioaccessibility and stability of ferrous bisglycinate.
• The chelation mechanism involves CPP's carboxyl and amino groups, improving antioxidant properties.
• This study provides a foundation for developing advanced iron supplementation strategies with improved efficacy and tolerability.