Effect of Acid Pretreatment on the Stability of Ascorbic Acid Complexes with Various Iron Sources in a Wheat Flake Cereal

Abstract

The effect of acid incubation of ascorbic acid with each of five iron sources (ferrous sulfate, ferric chloride, ferric orthophosphate, hydrogen and electrolytically reduced iron) on iron solubilization in a wheat flake cereal was evaluated. Incubation produced more soluble iron at pH 2 but not necessarily at the endogenous pH of the cereal nor at pH 6. At pH 2, Fe+* rather than Fe+3 was produced, apparently by a reduction of bound Fe+3 and subsequent release of Fe+*. At pH 6, the soluble iron was mainly in a complexed form. This indicates that acid incubation with ascorbate might facilitate bioavailability of iron if it were incorporated by fortification techniques.

Use of Soybean in Cereal Based Food Formulation and Development of Nutritionally Improved Foods

“…However, even if not a study of acceptability of these samples was made, it is estimated that this effect will not be noticed with the addition of salt, oil and flavorings normally done, for the final formulation of a commercial product. Regarding AA addition, the results obtained in relation to Fe availability differ from those reported by other authors (Clydesdale & Nadeau, 1985;Gorman & Clydesdale, 1983;Wolfgor et al, 1996). It should be noted that in these cases the foods were obtained under different processing conditions.…”

Characterization of Solution Properties of Four Iron Sources in Model Systems by Solubility Studies and IR/VIS Reflectance Spectrophotometry

“…However, it should be noted that this is, in reality, bathophenanthroline reactive iron and as such provides a measure of ionic iron as discussed by Clydesdale and Nadeau (1985).…”

“…Prep Tyrode buffer consists of (g): NaCl (16.0), KC1 (0.4), NaHzPO+HzO (0.13), NaHCOs (2.0), glucose (2.0), MgS04.7Hz0 (0.52) and CaClz(0.4), NaNs (0.4), made up to 2L with DDD. Half of the systems were treated with ascorbic acid (AA) (L-ascorbic acid, Fisher Scientific Co., NJ) at a molar ratio of 1.25: 1 ascorbic acid: iron as suggested by Clydesdale and Nadeau (1985). Each iron source was added to one AA-treated and one untreated model system.…”

Effect of Acid Pretreatment on the Stability of Citric and Malic Acid Complexes With Various Iron Sources in a Wheat Flake Cereal

“…In all experiments, 150 mL of DDD water was added alone, with an iron source, or with citric or malic acid and an iron source at 20.0 mg Fell00 g cereal, to each of three 4.7 g samples of cereal. Following blending, the samples were either analyzed at their endogenous pH (stage E), following a 20 min incubation at pH 2.0 (stage 2) or after both this treatment and neutralization to pH 6.0 to complete the fmal sequential pH treatment (stage 6), as discussed by Clydesdale and Nadeau (1985).…”

“…Recognizing both the potential for improved iron bioavailability through a citric or malic acid cofortification process and the effect of acid incubation on iron binding (Clydesdale and Nadeau 1985) this study was initiated in order to compare the effects of a ligand-iron incubation at pH 2 prior to addition to a wheat flaked cereal. Since solubility is a major criteria for the potential absorption of iron in vivo, it will be used here as a measure for predicting each ligand's effectiveness at various stages in a simulated gastrointestinal environment.…”