## 1 Introduction  
Mycotoxins are poisonous compounds produced as secondary metabolites by some species of fungi, including _Fusarium_, _Aspergillus_, _Penicillium_, and _Alternaria_[1; 2]. Trichothecenes are a large group of mycotoxins sharing 9, 10 double bond and the 12, 13 epoxide group in their structure [3]. Deoxynivalenol (DON), mainly produced by _Fusarium grameinarum_ and _Fusarium culmorum_, is one of the major trichothecenes that contaminates cereals such as barley [4]. DON can cause vomiting, anorexia, growth retardation, immune suppression, inflammation and the necrosis of various tissues,and diarrhea in animals [5; 6]. Barley is one of the major grains that is consumed as animal feed, used to produce cereal-based products and is widely used in brewing industries. DON in grains, especially in barley, reduces grain quality and financially impacts agricultural organizations. The economic loss associated with DON was estimated at $655 million/year in the United States from 1993 to 1996 [7]. Many strategies have been suggested for suppressing fungal growth and reducing mycotoxin formation, including pre-harvest methods (crop rotation, sowing date, tillage, use of fungicide), physical methods (i.e., dehulling, sorting, sieving, floatation, washing, steeping, milling, ultraviolet, gamma treatments, and thermal treatments), chemical methods (citric acid, acetic acid, lactic acid, NH\({}_{3}\), Ca(OH)\({}_{2}\), Na\({}_{2}\)CO\({}_{3}\), oxidizing agents, and reducing agents), enzymatic methods (amylases, glucanases, proteases), biological methods (fermentation, genetic engineering in plant genes for detoxification), and microbial decontamination method (prevention of ingestion by microorganism of gastrointestinal tract) [1]. Despite the progress achieved by using these methods, they have several disadvantages, including low efficacy, requirement of expensive chemicals and sophisticated equipment requirement. Furthermore, some of these methods may leave chemical residues that might cause a detrimental effect on the treated product, which may present health hazards to consumers. As a result, some of these methods are usually considered as impractical, costly, not completely effective, and time-consuming, especially for the large-scale treatment of food or feed products [1; 8]. Hence, there is a need to find an effective method to control DON contamination in food and feed products. Atmospheric cold plasma (ACP) technology is a novel technology with the potential to reduce fungi and mycotoxins' concentration [9]. The term plasma refers to an ionized state of a gas produced by increasing the internal energy of the gas. The ionization process leads to the formation of reactive species, radicals and UV light [9; 10]. Reactive oxygen species (ROS) such as ozone (O\({}_{3}\)), singlet oxygen (\({}^{1}\)O\({}_{2}\)), superoxide (O\({}_{2}\)\({}^{-}\)), peroxide (O\({}_{2}\)\({}^{-}\) or H\({}_{2}\)O\({}_{2}\)), hydroxyl radicals (OH), and reactive nitrogen species (RNS) such as excited molecules of N\({}_{2}\) and nitric oxide radical (NO) are the main effective species in ACP [11]. The degradation of mycotoxins by ACP could be related to their interaction with the reactive species, UV photons, and electrons. Mycotoxin degradation efficacy of ACP is greater than that of ozone or UV treatments, due to the possible contribution of reactive species, electron, and UV photon in the ACP treatment [1]. The low temperature of ACP is an important aspect in preserving quality while improving the safety of the product. ACP may also improve the germination rate of grains and length of seedlings [12]. Previous research reported the effectiveness of ACP to reduce mycotoxins, including DON, aflatoxin and T-2 toxin [1; 13; 14]. However, limited information is available on the efficacy of ACP to reduce DON on barley grains. Additionally, knowledge on the effect of ACP treatment on grain quality parameters and the germination capacity of barley is important for ACP treatment optimization.