## 1 Introduction  
Roasted meat, with its attractive colour, tenderness, and unique flavour, is popular with consumers worldwide. It is usually made from raw meat cured with salt and other seasonings and then roasted with charcoal or electric heat. During the curing process, nitrite is usually applied to improve the colour, texture, and flavour of meat products; it also inhibits lipid oxidation, protein oxidation, and the growth of aerobic and anaerobic microorganisms [1, 2]. However, during the thermal processing of meat products, nitrite and nitrate in meat are metabolized to nitrogen oxides, which in turn react with secondary amines to form carcinogenic \(N\)-nitrosamines [3, 4, 5].  
For food safety concerns, the substitution of natural nitrite or nitrate for the meat industry has been widely studied [2, 6, 7]. [PERSON] et al. [8] reported that radish and betroot powders (0.5% and 1%) with _Staphylococcus carnosus_ could be effectively used to replace nitrite in fermented sausages due to their high nitrate content. However, the content of nitrate in plants is easily affected by the external environment, such as temperature, season, soil, and storage conditions, and variety [1, 7]. In addition, the excessive addition of some plant powder, such as cherry powder, can affect the taste and flavour of processed meat products, such as pork patties [2, 9]. Therefore, it is necessary to find an effective replacement for nitrite/nitrate or new technology in the industry to achieve the multiple functions that nitrite plays during curing.  
Nonthermal plasma, the fourth state of matter in the universe beside solid, liquid, and gas [10], is generated by an electric discharge in a gas at atmospheric or low-pressure conditions and contains free radicals, atoms, ions, particles, and molecules [11]. Recently, it has been reported that the reactive nitrogen species in atmospheric nonthermal plasma can react with water molecules and generate nitrite in liquid, brine, or meat batter [12; 13; 14]. Consequently, atmospheric nonthermal plasma is gradually being applied to replace nitrite in meat products, such as emulsion-type sausage, ground ham, and pork jerky [15; 16; 17; 18]. [PERSON] et al. [15] observed that the total aerobic bacteria, colour, peroxide value, and sensory attributes of emulsion-type sausages cured with plasma-treated water were similar to those of sausages cured with sodium nitrite. Another study reported that the degree of lipid and protein oxidation and sensory evaluation of caused ground hams cured with plasma had no significant differences with those cured by nitrite or celery powder [16]. [PERSON] et al. [17] also found that the colour and residual nitrite content of pork jerky increased with increasing atmospheric pressure plasma treatment time, while the degree of lipid oxidation and pathogen count decreased. In addition, it was demonstrated that ground hams treated by remote plasma had a similar colour and lipid oxidation with those cured using nitrite, and the residual nitrite decreased rapidly during storage [18]. Based on the previous studies, atmospheric nonthermal plasma could be a potential method to replace sodium nitrite in meat product processing, while ensuring the sensory attributes of meat products.  
Therefore, the aim of this study was to evaluate the effect of atmospheric nonthermal plasma treatments (15, 30, and 45 min) on the sensory attribute of roasted lamb compared with sodium nitrite treatment. The feasibility of replacing nitrite with plasma treatment was studied by measuring the residual nitrite content, protein and lipid oxidation, colour, shear force value, volatile compounds, and sensory score of roasted lamb. Accordingly, this is expected to provide theoretical support for the application of atmospheric nonthermal plasma treatment in the meat industry to produce nitrite-free or low- nitrite meat products.