The stability of ferric pyrophosphate in foods is affected by various factors, which are as follows:
pH value: The stability of ferric pyrophosphate varies in environments with different pH values. Generally speaking, an acidic environment will promote its decomposition and cause the release of ferric ions. For example, under strongly acidic conditions with a pH value of 2 to 3, the structure of ferric pyrophosphate may be damaged, leading to the dissociation of ferric ions, thus affecting its stability in foods. In contrast, it is relatively stable in a neutral to weakly alkaline environment.
Temperature: An increase in temperature will accelerate the reaction rate of ferric pyrophosphate, reducing its stability. Under high-temperature conditions, it may undergo thermal decomposition reactions or chemical reactions with other components in the food. For instance, during the baking of baked goods, an excessively high baking temperature may cause the decomposition of ferric pyrophosphate, reducing its iron content and affecting the nutritional value of the food.
Water activity: Water activity reflects the availability of water in foods. High water activity is conducive to the growth of microorganisms and the occurrence of chemical reactions, which may lead to reactions between ferric pyrophosphate and other substances, reducing its stability. At the same time, excessive water may cause the hydrolysis reaction of ferric pyrophosphate, damaging its structure. Conversely, low water activity can inhibit the growth of microorganisms and chemical reactions, helping to maintain its stability.
Other components in foods: Some components in foods may interact with ferric pyrophosphate, affecting its stability. For example, reducing substances such as citric acid and vitamin C may reduce the ferric ions in ferric pyrophosphate to ferrous ions, thereby changing its chemical structure and properties. In addition, anions such as phosphates and carbonates may also undergo ion exchange reactions with it, affecting its stability.
Light: Light will have an impact on the stability of ferric pyrophosphate. In particular, high-energy light rays such as ultraviolet rays may trigger its photochemical reactions, causing changes in its structure and leading to the release of ferric ions or the decomposition of the compound. For example, in foods exposed to sunlight for a long time, the stability of ferric pyrophosphate will be significantly reduced.
