Quality evaluation of used cooking oil for deep frying

Abstract

The objective of this project was to establish an optimum number of times for which edible cooking oils could be reused for deep frying without surpassing the standards of oil parameters safe for consumption. This was achieved by separately analyzing the change in the smoke point, Peroxide values and free fatty acid values of BUL fortune gold after ten frying cycles of fries and sausages. The smoke point was 224°C for the first fry cycle and 220°C for the second. The peroxide values had an overall increase for all the cycles, however, the standard limits were not surpassed by both the fries and sausages. The Free fatty acid values also had an overall increase but the standard limits were surpassed by both sausages and fries on the seventh cycle. It was then concluded that reuse of cooking oil can be done to a maximum of six times using BUL fortune gold as a reference sample for the other oil brands in the Ugandan market. It was also concluded that the smoke point is not usually reached by vendors because the food stuffs do not get fried well at such very high temperatures close to the smoke point. Lastly, it was concluded that different food stuffs affect oil quality differently though not profusely. It was then recommended that other parameters of cooking oil like Iodine absorption value, paraanisidine value, total oxidation value and color value be examined and also different cooking oil brands common on the Ugandan market like sun seed, mukwano and many others. Lastly different food stuffs commonly sold on the Kampala streets like samosas, pancakes, cassava and many others foods should be used to carry out the research because different food stuffs affect oil quality differently as was observed.