ABSTRACT
BACKGROUND: Deferriferrichrysin (Dfcy) is a siderophore found in foods fermented by Aspergillus oryzae and is a promising candidate for an antioxidant food additive because of its high binding constant toward iron. However, the Dfcy concentration is typically low in foods and cultures. RESULTS: We optimised culture conditions to improve Dfcy production to 2800 mg L(-1) from 22.5 mg L(-1) under typical conditions. Then, we evaluated the potential of Dfcy as a food additive by measuring its safety, stability, and antioxidant activity. Dfcy was sufficiently stable that over 90% remained after pasteurisation at 63 °C for 30 min at pH 3-11, or after sterilisation at 120 °C for 4 min at pH 4-6. Dfcy showed high antioxidant activity in an oil-in-water model, where inhibition of lipid oxidation was measured by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) assays. Dfcy decreased PV and TBARS by 83% and 75%, respectively. Antioxidant activity of Dfcy was equal to or higher than that of the synthetic chelator EDTA. CONCLUSION: Our study provides the first practical method for production of Dfcy. Dfcy can be a novel food-grade antioxidant and the first natural alternative to the synthesised iron chelator EDTA. © 2015 Society of Chemical Industry.
Subject(s)
Antioxidants/isolation & purification , Aspergillus oryzae/chemistry , Food Preservatives/isolation & purification , Iron Chelating Agents/isolation & purification , Models, Chemical , Peptide Hydrolases/metabolism , Peptides, Cyclic/isolation & purification , Animals , Antioxidants/adverse effects , Antioxidants/chemistry , Antioxidants/economics , Aspergillus oryzae/growth & development , Aspergillus oryzae/metabolism , Fermentation , Food Preservatives/adverse effects , Food Preservatives/chemistry , Food Preservatives/economics , Food-Processing Industry/economics , Fungal Proteins/metabolism , Hot Temperature/adverse effects , Industrial Waste/analysis , Industrial Waste/economics , Iron Chelating Agents/adverse effects , Iron Chelating Agents/chemistry , Iron Chelating Agents/economics , Japan , Mutagenicity Tests , Oryza/chemistry , Peptides, Cyclic/adverse effects , Peptides, Cyclic/chemistry , Peptides, Cyclic/economics , Plant Proteins, Dietary/chemistry , Plant Proteins, Dietary/economics , Plant Proteins, Dietary/isolation & purification , Plant Proteins, Dietary/metabolism , Protein Hydrolysates/chemistry , Protein Hydrolysates/economics , Protein Hydrolysates/isolation & purification , Protein Hydrolysates/metabolism , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae/metabolism , Seeds/chemistry , Toxicity Tests, Acute , Wine/analysis , Wine/microbiologyABSTRACT
Ferrichrysin (Fcy), which is produced by Aspergillus oryzae and is present in foods used for human consumption, belongs to a group of hydroxamate siderophore ferric iron chelators. Fcy (100 mg/mL) dissolves completely at both pH 2.0 and 7.0, being very stable at a wide range of pH, high temperatures and pressures, with little reactivity to dietary iron absorption inhibitors, phytic acid, tannic acid, and catechin. We studied the effect of Fcy in male Sprague-Dawley rats with iron-deficiency anemia, which were separated into three different dietary groups (n=5) and supplementing diets as follows: (i) ferric citrate, (ii) heme iron concentrate, and (iii) Fcy (35 mg Fe/kg diet) for three weeks. Fcy exhibited the same beneficial effect in improving iron deficiency anemia as ferric citrate, being significantly greater than the effect of heme iron. The iron concentration of liver in the Fcy group was 35% greater than that in the ferric citrate group. These findings indicate that Fcy could be an efficient oral iron supplement to prevent or treat iron deficiency.
