Effect of selected ions from lyotropic series on lipid oxidation rate

Organic or inorganic salts, commonly present in foods as natural components or ingredients, can affect the hydrophobic/hydrophilic interactions among food components. In particular, modifying the physicochemical equilibrium in the media, the ionic species forming salts could affect the kinetics of chemical reactions occurring in foods. The aim of the present research was to study the influence of different ionic species from lyotropic series on the kinetics of lipid oxidation. For this purpose, salts containing antichaotropic (carbonate and acetate), neutral (Na+, K+) and chaotropic ions (Cl-) were added to soybean oil. Results indicate that potassium carbonate and potassium acetate present a strong antioxidant capacity, whereas no effect was detected for NaCl and KCl. The salt antioxidant activity was prevalently attributed to the antichaotropic anionic species present in the media, which could interact with hydroperoxides by virtue of their ability to form hydrogen bonds. These results appear to be of considerable interest for controlling the development of rancidity in foods. (c) 2005 Elsevier Ltd. All rights reserved.