###### Abstract  
Sea fennel (_Crithimum martimum_ L.) is a strongly aromatic herb of the Apieceae family, whose full exploitation by the modern food industry is of growing interest. This study aimed at investigating the microbiological quality, volatile profile, and sensory traits of sea fennel spices produced using room-temperature drying, oven drying, microwave drying, and freeze drying. All the assayed methods were able to remove moisture up until water activity values below 0.6 were reached; however, except for microwave drying, none of the assayed methods were effective in reducing the loads of contaminating microorganisms. The metataxonomic analysis highlighted the presence of phytopathogens and even human pathogens, including members of the genera _Bacillus_, _Pseudomonas_, _Alternaria_, and _Cryptococcus_. When compared to fresh leaves, dried leaves showed increased L* (lightness) and c* (chroma, saturation) values and reduced hue angle. Dried leaves were also characterized by decreased levels of reprene hydrocarbons and increased levels of aldehydes, alcohols, and esters. For the sensory test, the microwave-dried samples obtained the highest appreciation by the trained panel. Overall, the collected data indicated microwave drying as the best option for producing sea fennel spices with low microbial loads, brilliant green color, and high-quality sensory traits. rock samphire; dried spices; microwave drying; metataxonomic; _Bacillus_; _Pseudomonas_, _Alternaria_; _Cryptococcus_  
30 August 202  
of heat from the hot air to the surface and, hence, to the interior of the product, and a flow of mass (steam) from the inner part of the product to the surface and, hence, to the air [3; 4]. Convective air drying is widely used in the food industry due to the low cost of this technology [3]. In microwave drying, heat is generated within the product due to the absorption of microwave energy by water molecules. Subsequently, water evaporation occurs within the product, followed by water diffusion as steam moves from the interior of the product to its surface. The capability of this method for producing high-quality dried herbs within a short processing time is widely acknowledged [3; 5; 6]. Nevertheless, further research efforts are needed for optimizing the process parameters for drying of species with different microwave energy absorption capacities [7]. Lastly, the freeze-drying technology removes moisture through the sublimation of water from the solid to the vapor state. Despite the high cost, this method is widely used for drying fruits and vegetables, whose bioactive compounds can be retained due to the use of low temperatures and the lack of water and oxygen during the process [8]. Besides their culinary use as flavoring agents, some spices, such as basil, thyme, co-riander, cumin, oregano, and parsley, are used for medicinal purpose in the traditional Mediterranean diet due to their high concentration of bioactive compounds, mainly consisting of polyphenols and essential oils [9; 10; 11; 12]. Although the antimicrobial properties of some of these spices have been identified, their exploitation for enhancing the savory experience of foods might also lead to microbial contamination and spoilage. Endospores produced by spore formers introduced by spices into foods, mainly belonging to the genera _Bacillus_ and _Clostridium_, can survive through different preparation processes, including thermal treatments, thus leading to changes in food quality and safety during storage [13]. _Crithum maritium_ L., commonly known as sea fennel, is a highly aromatic herb belonging to the Apiaceae family, like parsley, coriander, and cumin [14; 15; 16]. Traditionally, leaves can be consumed fresh in salads for their spicy and salty taste, cooked in soups, or consumed as pickles [17; 18; 19; 20], whereas flower tops and stalks are used for the preparation of herbal teas and infusions [21].