Effect of storage periods on peroxides of edible fats and oils

Abstract

This experiment was conducted on 15/9/2022  in the laboratories of Al-Fadhel   Company in the city of Hilla, after extracting animal fats (tall fat sheep , sheep belly oil, Cow oil and Butterfat) by thermoplastic method, sesame oil by pressing method, and hydrogenated oil from the markets, in stages, to observe the development of the first stage of fat oxidation due to exposure to heat, oxygen, light, and humidity at room temperature, which produces roots Free peroxide assay (PV).As well as the second stage, which produces aldehydes and ketones with a rancid smell, by examining thiobarbituric acid. The results of the peroxide test showed that there was no significant difference, and the peroxide values varied within the Iraqi standard. As for the TBA test.The results showed the influence of the source of oil and fat, so the hydrogenated oil excelled as an indication of its exposure to abnormal storage conditions that led to the beginning of oxidation and the formation of aldehydes and ketones, and immediately after the 15th day it came out of control according to the standard specification, to be followed on the 18th day by the release of free fat and sheep belly fat, due to the high level of unsaturated fatty acids. As the results of the current study showed, the lack of antioxidants, then on the 20th, sesame oil got out of control due to its high content of unsaturated fatty acids. Then, on the 23rd, the bovine fat gets out of control, and the beef fat is the only one that gets out of control. On the 30th, that is, the last two samples that got out of control is the buttock fat and the beef fat.