## 1 Introduction  
Meat products possess nutritional characteristics that favor the growth of a wide diversity of foodborne pathogens, making them a public health concern [1]. _Listeria monocytogenes_, a Gram-positive bacterium commonly found in soil, water, and mammals, is responsible for listeriosis, a serious foodborne illness with high hospitalization and mortal ity rates [2; 3]. Gastrointestinal symptoms can progress to severe systemic complications, particularly in pregnant women, immunocompromised individuals, and the elderly [4]. In 2023, the European Food Safety Authority (EFSA) reported a 5.8% increase in listeriosis cases compared to 2022, with nearly all cases requiring hospitalization and a total of 335 deaths [4]. In North America, the Centers for Disease Control and Prevention (CDC) has reported _L. monocytogenes_ outbreaks linked to vegetables [5], ice cream [6; 7], cheeses [8], and meat [9], causing over 1500 illnesses and 200 deaths per year [10]. Its continued presence in the U.S. has potential implications for neighboring countries, such as Mexico, where similar risks are likely associated with cross-border food trade and consumption patterns [11]. The persistence of _L. monocytogenes_ in food environments is attributed to its ability to survive under stressful conditions [12], such as low or high temperatures (<5 \({}^{\circ}\)C and >60 \({}^{\circ}\)C) [1; 13], acidic pH [14], and moderate salt levels [15]. Long-term exposure to these stress conditions potentially leads to increased resistance [16; 17]. To address this challenge, hurdle technologies have been explored, combining mild thermal treatments with natural antimicrobials, such as essential oils (EOs) [18; 19; 20; 21]. These natural compounds, classified as \"Generally Recognized as Safe\" (GRAS), interact with bacterial membranes, altering permeability and leading to cellular damage [22]. Among them, oregano EO--particularly _Origanum vulgare_--is well studied for its efficacy against Gram-positive bacteria, including _L. monocytogenes_[23; 24; 25]. For instance, it has been demonstrated that sublethal concentrations (SLC) of _O. vulgare_ (1.25 \(\mu\)L/mL) at 30 \({}^{\circ}\)C can alter the growth parameters of _L. monocytogenes_ after 1 h of exposure [26]. This effect may improve the efficacy of antibiotics in medical applications or be combined with other inactivation treatments in the food sector [26; 27]. In the Americas, _Lippia graveolens_ (Mexican oregano) has been widely used for its antimicrobial properties [28; 29; 30; 31]. However, _Poliomithu longiflora_, another Mexican species with high levels of carvacrol and thymol, has been less explored [32]. Recent studies suggest that fractioning its EO enhances its bioactivity by concentrating key antimicrobial compounds [33; 34]. This local and underutilized resource offers a sustainable alternative for controlling foodborne pathogens [28], especially in countries like Mexico, where the regulatory surveillance of _L. monocytogenes_ is still developing [34], and contamination has been detected in vegetables [35], dairy [36], and meat products [11; 37]. Although previous research has demonstrated the antimicrobial effects of SLC of EOs combined with physical treatments such as High-Pressure Processing (HPP), freezing, irradiation or thermal treatments [1; 38; 39], little is known about the inactivation kinetics of _L. monocytogenes_ using fractionated _P. longiflora_ EO and mild pasteurization temperatures. Predictive microbiology tools such as the Weibull and Bigelow models can help estimate microbial reductions and optimize such interventions for practical food applications [40; 41; 42; 43]. Therefore, the aim of this study was to assess the impact of pure (PEO) and fractionated (FIV) _P. longiflora_ EO on the thermal inactivation of _L. monocytogenes_ at mild temperatures (52, 54, 57.5, and 63 \({}^{\circ}\)C), through an in vitro assay using a simulated meat medium.