Frying oil and fat quality measured by chemical, physical, and test kit analyses

The performance of soybean oil (SBO) and a partially hydrogenated soybean oil (PHSBO) was monitored by chemical, physical, and test kit analyses during 50 h of deep‐frying of potatoes in SBO and 50 h of deep‐frying of potatoes in PHSBO. The oxidative stability of SBO and PHSBO was measured by the iodine value, color index, FFA content, total polar compounds, and FA analysis of deep‐frying SBO and PHSBO. SBO, with higher levels of unsaturated FA, had the faster rate of formation of geometric and positional isomers of unsaturated FA as measured by GC with standards. PHSBO performance under deep‐frying conditions was significantly better than SBO with respect to iodine value, color index, and total polar compounds. The results from analyses using test kits had a good correlation with analytical parameters.