Determination of hydrogen peroxide index in the consumption edible oils in fast food shops

Peroxide is the first compound which is produced after oxidation of fats and oils. When the peroxide level increases to specific amount, adverse taste and odor will be released due to volatile compounds. Peroxides may contribute in different diseases such as; atherosclerosis, progeria, allergic inflammation, cerebral and cardiac ischemia, respiratory distress syndrome and different liver dysfunctions. The main objective of this study was to determinate hydrogen peroxide index in both cooked and uncooked (raw) oils in fast food shops in Shahrekord during 2009 to 2010. This cross-sectional study was accomplished on 50% of Shahrekords’ sandwich shops. In this research, 160 samples were gathered from 40 sandwich shops (4 samples per shop, two samples from uncooked and two samples from cooked oils) in the beginning and the end of the week, respectively. Samples were analyzed for hydrogen peroxide based on Association of official analytical chemists (AOAC). Allowable standard levels of hydrogen peroxide for solid and liquid oils are 2 meq/kg and 5 meq/kg, respectively. Data were analyzed with application of Mann-Whitney U-test and Wilcoxon Signed Ranks Test using SPSS software. Results showed that peroxide value was more than standard level in all of samples. Peroxide increasing percentages for two kinds of oils were as below: 1- for uncooked oils 45% in the beginning and 25% at the end of the week; 2- for cooked oils 100% in the beginning and 97.5% at the end of week. According to the statistical analysis, there is significant relationship between uncooked and cooked oils in the beginning and at the end of the week both in edible and fried oils (P<0.001). However; no significant relationship was found between cooked oils in the beginning and at the end of the week both in edible and fried oils (P>0.05). Based on the results of this study, approximately 100% of solid and liquid cooked oils (both edible and non-edible oils) had a peroxide index higher than standard limit. It is highly recommended that health centers authorities try to manage a specific educational program for fast food shops owners and also they have to schedule time table for proper supervision