Analysis of 8-oxooctanoate, 9-oxononanoate, fatty acids, oxidative stability, and iodine value during deep-frying of French fries in edible oils blended with palm oil.

Four blended oils including palm + corn oil (PC), palm + grapeseed oil (PG), corn + grapeseed oil (CG), and palm + corn + grapeseed oil (PCG) were used as frying media. The 8-oxo and 9-oxo content, fatty acid composition, oxidative stability index, and iodine value of samples (n = 42) were analyzed. As the frying cycles increased, the content of 8-oxo and 9-oxo also increased significantly (p < 0.05) and showed the highest content of 965.56 ± 0.706 μg/g in 100 frying cycles of PCG. After 20-40 frying cycles in CG, the amount of palmitic, stearic, oleic and linoleic acid increased up to 15.5% (p < 0.05). The oxidative stability of palm oil was the highest at 16.76-18.33 h (p < 0.05). The iodine value of grapeseed oil was the highest at 144.96 ± 2.569-153.64 ± 2.233 g iodine/100 g oil (p < 0.05). Among the examined oils, PC was the most suitable alternative to palm oil.