## 1 Introduction
EOs, rich in bioactive compounds such as phenolics, terpen, and aldehydes, exert their antioxidant effects mainly through free radical scavenging mechanisms. These molecules donate hydrogen atoms or electrons to neutralise free radicals, thus interrupting oxidative chain reactions. Moreover, some essential oil (EO) components can chelate pro-oxidant metal ions, further inhibiting oxidative damage in meat matrices [20]. Incorporating EOs into meat products offers a promising natural strategy to enhance product stability and safety while meeting consumer preferences for clean-label foods. Several authors agree that the composition of CEO is responsible for its antioxidant activity since these molecules are those that influence the reduction and elimination of free radicals present in the matrix. [PERSON] et al. [21] and [PERSON] et al. [22] agree that the phenolic content present in a solution allows researchers to indicate its antioxidant potential due to the close relationship that exists between both parts. [PERSON] et al. [23] established that the ability to neutralise free radicals is influenced by phenolic compounds since flavonoids provide hydroxyl groups that react with radicals. The antioxidant activity of polyphenols can be explained by considering the presence of the phenolic H atom. The latter can interact with peroxyl radicals, stabilising them by resonance and generating unreactive adducts; this mechanism interrupts the propagation of the oxidative chain [24]. The composition of an EO is around 300 compounds (majorities, minorities, and traces). However, most studies emphasise the antioxidant potential of eugenol. According to the literature, this molecule is a ferric ion reducing agent with electron donor properties that allow free radicals to be neutralised and stable compounds to be formed [25]. [PERSON] et al. [23] point out that a eugenol molecule could reduce two or more 1,1-diphenyl-2-picrylhydrazil (DPPH) radicals, which generates eugenol dimers with two phenolic hydroxyl groups from eugenyl intermediate radicals. CEO can prevent or slow down lipid and protein oxidation reactions in meat and the formation of unwanted volatile compounds, helping preserve the nutritional and sensory quality of meat and meat products [26]. This systematic review aims to compile and analyze the available scientific evidence on the antioxidant activity of CEO in meat and meat products, with the aim of providing a comprehensive view of its effectiveness and possible applications in a meat production context for healthier and safer foods, which is in line with the demands of current consumers [27]. There are several studies on the antioxidant activity of essential oils [28; 29]; however, the novelty of this review lies in its systematic and specific focus on the antioxidant application of CEO in meat and meat products. To the best of our knowledge, there is no prior systematic review addressing this topic. The available evidence is scattered and presents variable results, so this review seeks to consolidate existing information, identify research gaps and provide a solid scientific basis for future applications of CEO in the food industry.