Deep-Frying Performance of Palm Olein and Sunflower Oil Variants: Antioxidant-Enriched and High-Oleic Oil as Potential Substitutes

Deep-fat frying remains the predominant method of food preparation; however, increasing concerns regarding health and sustainability have prompted the search for safer alternatives. Palm olein is widely used as a frying medium but its consumption has been questioned due to the presence of contaminants (e.g., 3-monochloropropane-1,2-diol, 3-MCPD) and the challenges associated with its transportation from producing countries, creating a need for healthier and more sustainable alternatives. The present study aimed to assess the oxidative stability, physicochemical properties, and sensory characteristics of various oils used for deep-fat frying, with particular emphasis on identifying suitable replacements for palm olein. Five oils were evaluated: refined sunflower oil (RSO), RSO supplemented with tert-butylhydroquinone (RSO+TBHQ), RSO supplemented with rosemary extract (RSO+RE), high-oleic sunflower oil (HOSO), and palm olein (PO). Samples were evaluated before and after deep-frying of French fries, at 175 °C for 2.5 min, over a total of 12 consecutive frying cycles. The results demonstrated that palm olein and HOSO exhibited the highest oxidative stability (induction period determined by Rancimat method at 100 °C was 27 h and 26.2 h, respectively), whereas the addition of TBHQ (induction period 23.4 h) and rosemary extract (induction period 11.5 h) provided only a modest enhancement of RSO stability (induction period 9.6 h). Hierarchical cluster analysis grouped palm olein and HOSO together, confirming their similar stability, while RSOs formed a distinct cluster. These findings suggest that high-oleic sunflower oil represents the most promising, stable, and nutritionally advantageous alternative to palm olein, simultaneously supporting local production and improved dietary quality.