Frying Stability, Fatty Acid Composition, and Nutritional Evaluation of Cottonseed Oil, Sesame Oil, and Their Blend: A Comparative Study

ABSTRACT This study aimed to assess the fatty acid profiles and frying stability of cottonseed oil (CSO), sesame oil (SO), and their 1:1 blend. Oils were evaluated by determining their nutritional quality, including the fatty acid profile and key nutritional quality indicators such as atherogenicity index (AI), thrombogenicity index (TI), hypocholesterolemic/hypercholesterolemic (HH) ratio, and ratios of polyunsaturated fatty acids (PUFA) to monounsaturated (MUFA) and saturated fatty acids (SFA). Furthermore, the oils were characterized using FTIR, and the thermal degradation behavior of the oils was assessed using a thermal gravimetric analyzer (TGA) at a 100°C to 600°C temperature range. Frying stability was determined by subjecting the oils to frying at 180°C and measuring acid value and p‐anisidine value (p‐AV) pre‐ and postfrying, alongside changes in color, viscosity, and fatty acid profiles. The 1:1 blend of CSO and SO showed an improved fatty acid profile, with PUFA/MUFA and PUFA/SFA ratios of 2.03 and 2.45 compared to 3.26 and 1.95, respectively, in unblended CSO. Furthermore, the blend showed more balanced nutritional indices with lower AI and TI values (0.23 and 0.52) versus CSO (0.34 and 0.78) owing to modified fatty acid composition. After ten frying cycles, the CSO:SO blend exhibited a significantly lower p‐AV (79.04 ± 0.8) compared to unblended CSO (95.22 ± 0.8), and also exhibited moderate changes in color and viscosity values as compared to unblended oils, indicating reduced formation of secondary oxidation products. TGA results revealed less thermal degradation between 100°C and 400°C for the blend. The findings suggest that blending CSO with SO not only enhances oxidative resistance during frying but also provides a more nutritionally balanced fatty acid profile, making it a potentially healthier option for high‐temperature culinary applications.