INHIBITION OF IRON-FRUCTOSE-PHOSPHATE-INDUCED LIPID PEROXIDATION IN LECITHIN LIPOSOME AND LINOLEIC ACID EMULSION SYSTEMS BY SOME EDIBLE PLANTS

Abstract

ABSTRACT Inhibition of iron-fructose-phosphate-induced lipid peroxidation by ethanol extracts of 10 edible plants (Beta lomatogena, Chenopodium album, Chenopodium foliosum, Eryngium billardieri, Gundelia tournefortii, Lactuca serriola, Polygonum cognatum, Rumex scutatus, Tragopogon spp., Urtica urens) was investigated in two different lipid systems (lecithin liposome and linoleic acid emulsion). Oxidation of lecithin liposomes was measured by thiobarbituric acid reactive substances (TBARS) and oxidation of linoleic acid emulsions by the Fe(II)-thiocyanate. All extracts inhibited iron-fructose-phosphate-induced lipid peroxidation in both lipid systems, with C. album and C. foliosum extracts showing less inhibition of lipid peroxidation than the other extracts. Oxidation in each lipid system was also monitored using the measurement methods (TBARS and Fe(II)-thiocyanate) without addition of the extracts, and thus, prooxidant efficiency of fructose in each lipid system could be evaluated. It was determined that the liposome test system was more susceptible to iron-fructose addition than the emulsion system. PRACTICAL APPLICATIONS Fructose has been frequently used as a sweetener in industrial food products. We previously found that fructose increases lipid peroxidation in the presence of phosphate and trace amounts of iron ions. Consequently, inhibition of fructose-induced lipid peroxidation in food products would be important. It is shown here that some plant extracts retard fructose-induced lipid peroxidation. Therefore, antioxidant plant extracts could be used in fructose-containing foods to eliminate prooxidant effects of fructose.