Contribution of the Ratio of Tocopherol Homologs to the Oxidative Stability of Commercial Vegetable Oils

Abstract

The antioxidant activity of tocopherols in vegetable oils was shown to chiefly depend on the amount and the tocopherol homolog present. However, the most effective ratio of tocopherol homologs with regard to the antioxidant capacity has not been elucidated so far. The present study analyzed the effect of different tocopherol concentrations, homologs and ratios of homologs on markers of lipid oxidation in the most commonly consumed vegetable oils (canola, sunflower, soybean oil) stored in a 12 h light/dark cycle at 22 ± 2 °C for 56 days under retail/household conditions. After 56 days of storage, the α-tocopherol-rich canola and sunflower oil showed the strongest rise in lipid peroxides, yielding 25.1 ± 0.03 meq O2/kg (+25.3-fold) and 24.7 ± 0.05 meq O2/kg (+25.0-fold), respectively. ESR experiments, excluding effects of the oils’ matrices and other minor constituents, confirmed that a food representative tocopherol ratio of (γ + δ)/α = 4.77, as represented in soybean oil, led to a more pronounced delay of lipid oxidation than a lower ratio in canola (1.39) and sunflower oil (0.06). An optimum (γ + δ)/α -tocopherol ratio contributing to the oxidative quality of vegetable oils extending their shelf life has to be investigated.

Bioactive Compounds, Nutritional Quality and Oxidative Stability of Cold-Pressed Camelina (Camelina sativa L.) Oils

“…In the camelina oils investigated in this work, the ratio of the abovementioned acids ranged from 1.79 to 2.17, which again proves the high nutritional value of the camelina oils. This ratio is definitely better than that found in popular vegetable oils, e.g., rapeseed, sunflower, soybean oil [23,43,44].…”

Comparison of the Effects of Brazil Nut Oil and Soybean Oil on the Cardiometabolic Parameters of Patients with Metabolic Syndrome: A Randomized Trial

“…The increase in total antioxidant capacity detected in the SO group may be associated with the tocopherol contents present in this oil [31]. In contrast, it may be related to the observed increase in total cholesterol and LDL, indicating a probable defense response of the body against vascular oxidative stress [60].…”

“…Brazil nut and soybean oils are rich in UFAs, with values of 72.89% and 84.47% [31], respectively. Oleic acid w9 predominates in BNO (34.71%) and linoleic acid w6 predominates in SO (56.6%) [31]. These results are consistent with what has been reported in the literature [17,32,33].…”

“…The average tocopherol content in Brazil nut and soybean oils is approximately 190 µg/g and 980 µg/g, respectively, while for phenolic compounds, these values are 150 mg gallic acid equivalent (GAE)/100 g for BNO and 6 mg GAE/100 g for SO [31,[67][68][69][70][71]. Despite containing lower tocopherol levels and SO [31], this amount still provides antioxidant effects [68]. Moreover, its content of phenolic compounds reaffirms the antioxidant power of BNO [72], which probably determined its effect on lipid peroxidation.…”

Inadequacy of nutrients and contaminants found in porridge‐type complementary foods in Rwanda

“…The extract was completely evaporated using nitrogen gas, reconstituted in 1‐ml isopropanol, and analysed with HPLC‐UV at 295 nm. The HPLC analysis was performed as described previously (Pignitter, Stolze et al, ; Zaunschirm et al, ).…”