Abstract: Reusing cooking oil is a common practice in India. Oxidation and hydrolysis occur when oil is heated repeatedly due to thermal decomposition. It had been suggested that consumption of repeatedly heated oil could be a health hazard. The increasing use of edible oils and fats for the preparation of fried products requires an increasingly strict control in order to maintain the quality and safety of the fried foods. Due to the knowledge that the frying process alters the chemical nature of the heated oil and its consumption represents health risks. In this study, the measurements were performed in daily frying operations of these restaurants and were analysed repeatedly for the relevance of results. The Total polar compounds and peroxide values of some collected frying oil samples from which daily frying main areas of cities were measured by standard procedures. The results showed that the total polar materials in the range of 12.24% to 22.12% and which are within the norms of codex standards. Peroxide values are in the range of 12.36 to 26.65 meq O2/kg which deviated from the Codex standard value of 10 meq O2/kg. Acid values are 0.78-5.98 in the range which deviates safety standards. The results showed degradation in the both the properties of the vegetable cooking oil after repetitive frying. The standard deviation for AV, PV and TMC are in the range of 0.16-0.32 while in case of standard mean error it is in the range of 0.09-0.18. These results provided the basis for choosing the proper rapid-measuring device to control the quality of frying oil in restaurants.

Keywords: Deep Frying Oils, Total Polar Compounds, Acid Value, Peroxide Value.

| DOI: 10.17148/IARJSET.2020.7801