## 1 Introduction  
Food spoilage processes that occur after harvesting and during processing and transport are unavoidable. Even after processing to reduce the microbiological burden, various chemical and biological processes continue in foods and determine their shelf life. To reduce food waste, the food industry is using tools such as improving processing practices and developing novel packaging solutions, among others. Fat oxidation is one of the most important degradation reactions that affect food quality, food safety and consumer's perception as the oxidation process degrades fatty acids generating toxic aldehydes and decreasing the quality of the food product [1]. In this sense, the shelf life of food products is of a major concern for the food industry. This is especially important for the nuts industry, as most of the nuts contain high levels of fat. Peanuts (_Arachis hypogaea_) have roughly 50 wt.% of fat, with unsaturated fatty acids such as oleic and linoleic fatty acids accounting for more than 80% of the fat fraction. Sincethe susceptibility of unsaturated fatty acids to oxidation reactions is higher than that of saturated fatty acids, this composition makes peanuts particularly sensitive to oxidation. Other variables that affect lipid oxidation are temperature, water content, free fatty acid content, oxygen concentration, and the presence of prooxidant and antioxidant substances [2]. In this line, tocopherols present in peanuts (mainly \(\alpha\)- and \(\gamma\)-tocopherol homologues) act as an antioxidant barrier and protect unsaturated fatty acids from suffering oxidative damage [3]. When peanuts are being oxidised, the concentration of some volatile compounds such as hexanal, a rancidity indicator, increase as it is a secondary metabolite of lipid oxidation [4, 5]. Consequently, hexanal analysis is a useful tool to monitor oxidative damage in peanuts [6]. Nowadays, when peanuts are packed, the control of the oxygen concentration inside the packaging is achieved through the use of polyethylene/polpropylene (PE/PP). PE/PET multilayer films, among others, containing EVOH as an oxygen barrier layer [7]. Moreover, the modified atmosphere packaging (MAP) technology is also used but, even with these packaging solutions, there is an amount of residual oxygen (around 0.5-1 vol.%) inside the container that cannot be avoided. This accelerates oxidation reactions, reducing the shelf-life of peanuts [8]. For all these reasons, the use of active packaging has become a promising approach to the conventional packaging solutions. One type of active packaging consists of the direct addition of oxygen scavengers into packaging materials, therefore reducing further the concentration of oxygen in the packaging atmosphere (i.e., less than 1 vol.%) and extending the shelf life of the packed products. Currently, there are several types of available oxygen scavengers. According to [PERSON] et al. [9], oxygen scavengers can be classified in: metallic, inorganic, organic, polymer, and enzyme-based compounds. Metallic-based scavengers are compounds based on iron, palladium, or other transition metals that require a certain water activity in the food to provide moisture to facilitate the oxygen removal by the scavenger [10]. Since they need the presence of water, they are not suited for their use when low moisture foods are packaged. They are by far the most frequently used group, specifically those relying on iron salts. In recent years, much attention has been devoted to the development of oxygen scavengers of the other groups. In the organic-based group, compounds such as butylated hydroxytoluene (BHT), \(\alpha\)-tocopherol, or different flavonoids (catechin, quercetin... ) have been evaluated [4, 11, 12, 13]. In the recent literature, some oxygen scavengers have been developed for their use in packaging for peanuts. They include the incorporation of trans-polyisoprene, with cobalt chloride as a metallic catalyst, and polybutadiene to polyethylene films [14, 15].