engleski

Impact of metals from the environment on chemical changes in olive oil

Metal contamination sources have been increasing everywhere, with many documented cases of metal toxicity in mining industries, foundries, smelters, coal burning power plants and agriculture. Heavy metals such as cadmium, copper, lead, chromium and mercury are major environmental pollutants, and their toxicity is a problem of increasing significance for ecological, evolutionary, nutritional and environmental reasons. Heavy metal accumulation in the soil is of concern in agricultural production due to its effects on plants and their metabolic activities, possible bioaccumulation, food safety and human health. Humans and other living organisms are a part of the biogeochemical cycle of metals and directly exposed to their impacts. Virgin olive oils are high quality food with a balanced triglyceride composition that provides their nutritional and protective value. The ideal composition of olive oil does not automatically imply a positive effect on health. Namely, during ripening, harvesting and processing of olives, especially during oil storage, oxidation processes can occur on triglycerides and can significantly affect the quality and safety of virgin olive oil. These chemical changes in virgin olive oil are provoked by exposure to air, heat and light but these processes can be catalysed at increased contents of heavy metals. This paper presents the results of lead, copper and iron content in 81 samples of virgin olive oil. Results are correlated with chemical parameters that indicate oxidation processes. Concentrations of lead ranged from <0.001 to 1.13 mg/kg, moreover in 21 samples the lead content was above the maximum permissible level. Concentrations of copper and iron were between <0.001 to 6.56 mg Cu/kg and <0.001 to 22.7 mg Fe/kg. In 49 samples (60.5%) concentration of metals was above the permissible level, and in 59% of these samples the oxidative changes have been observed. The results indicate a correlation between increased concentrations of metals and oxidation of the virgin olive oil.

heavy metals; environment; virgin olive oil; oxidation

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