Abstract Oxidation, hydrolysis, and polymerization are chemical processes that can occur during frying, leading to the formation of both volatile and non-volatile oxidative compounds. These substances reduce the natural antioxidants in fried palm olein and lower its quality. This study evaluated the oxidative stability of frying oil using korari seed, and Koester leaf extracts. Folin-Circlet, 2,2-Diphenyl-2-Picryl-hydrazyl (DPPH), ferric ion reducing antioxidant power (FRAP), phosphomolybdenum, and coulometric titration were among the techniques used to get the data. According to the results, Koester had the greatest total flavonoid content (52.9 ± 3.9 mg CE/g of dry extract) and total phenolic content (TPC) (34.6 ± 4.4 mg GAE/g of dry extract). Additionally, Koester demonstrated significant effects on DPPH scavenging with half-maximum inhibitory concentration (IC50) of 35.8 μg/mL, FRAP (IC50 = 157 μg/mL), and total antioxidant activity of 0.9 mg AAE/g of dry extract. The oils treated with coreset exhibited the strongest inhibition of thiobarbituric acid reactive compounds (81.95%) and the lowest peroxide value (7.7 me/kg). Furthermore, the free fatty acid content (0.478% oleic acid) and iodine value (9.64 g of I2/100 g) were minimized in oils treated with koshered by the end of the frying day. However, throughout the frying process, the rate of lipid oxidation in the control oil was greater. In conclusion, the mixed extracts of korarima and koseret work synergistically to inhibit oxidation during frying, enhancing the stability and quality of frying oil.
Megersa et al. (Sat,) studied this question.