When present in high concentrations in wine and other beverages, polyvalent metal cations such as iron may cause objectionable sensory and physicochemical properties including metallic taste, discoloration, oxidative changes, and formation of haze and cloudiness. Reducing metal concentrations in beverages, especially wines, has long been desirable. In this investigation, phytic acid was added to red, white, or model wine to chelate polyvalent iron cations in a phytic acid to iron molar ratio of 1:1, which corresponds to 0.018 mM phytic acid or 11.8 mg/L phytic acid for each 1 mg/L iron present. A calcium salt was then added to coprecipitate the complex quantitatively, at a calcium to phytic acid molar ratio of 5:1, which corresponds to 9.0 mg/L CaCO3 for each 1 mg/L iron subsequently removed by filtration. The method removes excessive iron in wine, sparkling wine, and other beverages and overcomes the problems of alternative methods; for example, it binds iron to the most complete extent possible, produces no toxic products even with overclarification, and acts selectively on iron and calcium ions but not on copper or potassium ions. Color and phenolic attributes were measured spectrophotometrically and were not greatly affected by phytic acid and calcium carbonate treatments. Titratable acidity and pH were slightly changed after treatment; however, such changes could likely be diminished with further work.
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