Ferric pyrophosphate is a commonly used food additive, mainly used as an iron fortifier. The following components in food may react with ferric pyrophosphate:
Acidic substances: Acidic components such as citric acid, malic acid, and phosphoric acid in food will react with ferric pyrophosphate. These acidic substances will lower the pH value of the solution, increasing its solubility, and may thus lead to the release of iron ions. For example, in some acidic beverages, it may react with citric acid, causing the iron ions to exist in a form that is more easily absorbed by the human body.
Reducing substances: Substances with reducing properties such as ascorbic acid (vitamin C) can react with ferric pyrophosphate. Vitamin C can reduce the ferric ion in ferric pyrophosphate to ferrous ion. Ferrous ion has a higher absorption rate in the human body. Therefore, adding it to some foods rich in vitamin C can improve the bioavailability of iron.
Proteins: Proteins in food can interact with ferric pyrophosphate. Amino acid residues in protein molecules contain functional groups such as amino groups and carboxyl groups, which can form complexes with iron ions. For example, in dairy products, proteins such as casein will combine with ferric pyrophosphate, affecting the existing form and stability of iron.
Phytic acid: Phytic acid is widely present in foods such as grains and legumes. It can form stable complexes with ferric pyrophosphate. Phytic acid has a strong binding ability to iron ions, which will reduce the bioavailability of iron. When adding ferric pyrophosphate to some grain-based foods, the influence of phytic acid needs to be considered.
Dietary fiber: Some components in dietary fiber such as hemicellulose and pectin may also react with ferric pyrophosphate. They can bind to iron ions through ion exchange or complexation, affecting the distribution and absorption of iron in food. For example, in some high-fiber foods, dietary fiber may encapsulate ferric pyrophosphate, delaying its release and absorption.
