Herb salt as a strategy to reduce the formation of polycyclic aromatic hydrocarbons in cooked beef

Polycyclic aromatic hydrocarbons (PAHs) are contaminants that can be formed during the thermal processing of food, especially through pyrolysis and thermal degradation of food constituents. Studies indicate an association between exposure to PAHs and an increased risk of cancer, and the use of natural ingredients with antioxidant potential may represent a strategy to reduce the formation of these compounds during food preparation. This work aimed to evaluate the effect of herb salt on the formation of 9 PAHs in rump steak subjected to different cooking methods. The herb salt mixture (containing salt, lemon powder, oregano, rosemary, basil, garlic, and onion) was formulated according to ANVISA guidelines. Meat samples, with and without herb salt, were cooked on an electric grill and a charcoal barbecue, under two internal temperatures (80 and 100 ºC). Analytical method for PAH determination included saponification, liquid-liquid extraction, purification by solid-phase extraction clean-up, and quantification by liquid chromatography. The addition of herb salt showed a tendency to reduce the formation of PAHs compared with untreated samples. On the electric grill, the sum of the nine PAHs in the unseasoned samples was 1.65 and 1.40 µg/kg at 80 and 100 °C, respectively, while none of the PAHs were quantified in the samples treated with herb salt. On the charcoal barbecue, the addition of herb salt reduced the sum of 9 PAHs by 28% at 80 °C (2.29 to 1.65 µg/kg), and by 39% at 100 °C (2.22 to 1.35 µg/kg). The results observed may be associated with the antioxidant properties of phenolic and organosulfur compounds present in ingredients such as oregano, rosemary, basil, garlic, and onion, which can interfere with the oxidative and thermal reactions involved in the formation of PAHs, as well as with the presence of lemon. Considering that lipids are key precursors of PAH formation during cooking, bioactive compounds can act by protecting the lipid matrix against initiators during the initiation phase or by blocking chain reactions during the propagation phase of thermal oxidation. Thus, the use of herb salt may represent a practical strategy to reduce the formation of PAHs during the preparation of beef. Further studies evaluating the individual contribution of the ingredients and their bioactive compounds are needed to clarify the mechanisms involved in this effect. Acknowledgements: São Paulo Research Foundation - FAPESP (Process no. 2018/19005-6).