The effect of rosemary extract on 3-MCPD and glycidyl esters formed during frying

The aim of this study was to determine the effect of rosemary (Rosmarinus Officinalis L.) extract on the formation of 3-MCPD and glycidyl esters during deep-fat frying. The study has consisted of two main stages. In the first stage, the patato samples were kept submerged in different concentrations (0; 1; 2,5 and 5%) of NaCl solutions and they were fried in sunflower oils containing different concentrations (0, 500, 1000 and 2000 ppm) of rosemary extract. In the second stage, repeated frying was carried out with sunflower oil enriched with rosemary extract (2000 ppm). In both stages of the study, the frying oil and the oil extracted from potato samples were analyzed in terms of the contents of 3-MCPD esters and glycidyl esters according to the method DGF C VI 18 (10). The oil samples obtained from repeated frying were analyzed for their contents of total polar compounds, free fatty acids as well as p-anisidin value, photometric color index, fatty acid composition and iodine value. The results have shown that the amounts of 3-MCPD and glycidyl esters were not affected significantly by different NaCl and rosemary extract concentrations. During repeated frying, the samples added by rosemary extract had lower free fatty acid content, lower p-anisidine value and higher iodine value.