## 1 Introduction  
Orange juice is one of the most popular juices sold around the world. It can be sold freshly squeezed, concentrated, or pasteurized. Pasteurized orange juice is produced from freshly squeezed oranges or reconstituted juice. The concentrated and the pasteurized juices go through thermal processes that extend their shelf-life. Most volatiles are lost due to thermal degradation during the concentration and pasteurization of orange juice. Industries bypass part of the juice or add orange essential oil to premium quality orange juice to improve its flavor. Unfortunately, this addition does not fully reconstitute the juice's natural aroma [1].  
Novel technologies are being studied and developed to improve food quality. In most studies, non-thermal technologies, such as high hydrostatic pressure (HPP) [2], high-pressure homogenization (HPH) [3], and supercritical CO\({}_{2}\) processing [4], are used in substitution for thermal processes to preserve thermolabile compounds, such as aroma compounds [5]. Although industrial processing of orange juice with novel technologies, such as high-pressure processing and pulsed electric field processing, is current practice, scale-up problems and economic viability when processing commodities such as orange juice are still disadvantages of cold plasma technologies. Thus, orange juice and many other commodities are still processed using thermal technologies, which are fast and cheap compared to several other processes.  
Lower-priced orange juice is often reconstituted and pasteurized orange juice that contains a reasonable amount of off-flavor compounds. Orange essential oil or the aroma recovered from the juice concentration process is added to premium-quality orange juice to improve the flavor and masquerade off-flavors. However, undesired off-flavor compounds remain in the juice.  
Previous studies from our group [6] showed that cold plasma technology could induce changes in terpenoid compounds, the main class of compounds present in orange juice.  
Plasma processing induces hydrogenation, scission, hydrolysis, isomerization, dehydrogen-genation, ring-opening, and ring-closure reactions that can be controlled by setting the proper operating conditions [6; 7]. Theoretically, these reactions can transform the low-odor limonene into more distinguished orange-like odor compounds, such as a-pinene and 3-carene, produce orange-characteristic aldehyde compounds, such as octanal and decanal, and mitigate off-flavor compounds, such as a-terpineol, by transforming it into other terpenoid compounds [6; 8]. These plasma-induced reactions fall within the scope of green chemistry processing since they are similar to naturally occurring reactions in plants that do not require the addition of any reagent or solvent. Furthermore, cold plasma operates at low temperatures (below 30 \({}^{\circ}\)C), reducing any further degradation of the nutritional compounds.  
This study aimed to identify and discuss the chemical reactions induced by glow discharge plasma on pasteurized orange juice and evaluate if this plasma technology could be applied to improve the aroma profile of pasteurized orange juice while controlling or mitigating the contents of off-flavors.