Frying Stability of Purified Mid‐Oleic Sunflower Oil Triacylglycerols with Added Pure Tocopherols and Tocopherol Mixtures

To determine the effects of the addition of pure tocopherols to triacylglycerols, α, γ, and δ tocopherols were added singly and in various combinations to stripped mid‐oleic sunflower oil (SMOSUN). Tortilla chips were fried in the treated oils and then aged at ambient temperature to determine storage stability of the fried food. Frying oils were evaluated for total polar compounds (TPC) as an indicator of oil deterioration, and they were also analyzed for retention of tocopherols. To determine effects of tocopherols on fried‐food stability, chips were evaluated for hexanal as an indicator of oxidative stability and for odor characteristics by a trained, experienced analytical sensory panel. Oils extracted from the tortilla chips were also analyzed for residual tocopherols. TPC were highest in the SMOSUN control with no additives followed by the SMOSUN containing only α tocopherol. The SMOSUN oil containing γ tocopherol had the best fry life as indicated by the lowest TPC. Hexanal content and rancid odor intensity were highest in the chips fried in the SMOSUN control and in the SMOSUN containing only α tocopherol. The most stable tortilla chips were fried in SMOSUN containing all three (α, γ, and δ) tocopherols; however, the lowest hexanal levels were measured when γ and δ tocopherols were added at their highest concentrations.