Changes in chemical properties and oxidative stability of refined vegetable oils during short‐term deep‐frying cycles

Abstract

In this study, changes in chemical properties, oxidative stability, fatty acid composition (FAC) and Fourier transform infrared (FTIR) spectra of soybean (SBO), rice bran (RBO), canola (CNO), cottonseed (CSO), and sunflower (SFO) oils during short-term deep frying of chickpea splits were determined. Free fatty acid (FFA), peroxide value (PV), p-anisidine value (p-AV), and viscosity of refined vegetable oils increased while the oxidative stability index (OSI) decreased with increment in frying cycles (FCs). The minimum changes in FFA, PV, p-AV, viscosity, and OSI were observed in SBO till fifth FCs. Oil uptake was also low in SBO and high in CNO after 5th and 10th FCs. CNO, RBO, and CSO exhibited higher changes in FAC and FTIR spectra (peak intensities at 3,009, 2,925, 2,854, and 1,745 cm−1) compared to SBO and SFO with increment in FCs. Thus, SBO with admissible ω6/ ω3 ratio (9.42:1) is suitable for short-term deep frying of chickpea splits. Practical applications In the deep-frying process of chickpea splits, five vegetable oils behaved differently in quality and stability characteristics. Soybean oil exhibited minimum changes in FFA content, viscosity, and OSI with increment in frying cycles. Oil uptake was lowest in soybean oil and it contains a desirable FAC for health benefits. Thus, soybean oil is recommended for short-term deep-frying operations among the studied vegetable oils.