## 1 Introduction  
Potatoes are considered one of the major starch carbohydrate crops, following wheat, rice, and corn [1]. China is the world's largest producer of potatoes, while North America and the European Union play a leading role in the global potato processing industry [2]. Potatoes are highly nutrient-rich vegetables, containing significant amounts of starch, sugar, dietary fiber, and small amounts of protein and fats, along with vitamin C [3]. However, despite these nutritional benefits, the consumption of potatoes has been reduced due to difficulties in preparation and storage [4]. Potatoes contain approximately 20% dry matter, of which 60-80% is starch [5]. Potato starch is widely used as an emulsifier, thickening agent, binder, and stabilizer [6], and its granules have a broad granule size distribution ranging from 1 to 110 \(\upmu\)m [7]. However, native potato starch has limited industrial application, because it cannot withstand extreme processing conditions, such as high temperature, acidic environment, and high shear rate [8]. Besides, native potato starch is insoluble in cold water, easily retrograded, and exhibits poor clarity [9; 10]. To address these issues, native potato starch can be modified through physical, chemical, or enzymatic methods [11]. Physical modification is an eco-friendly method, reducing the environmental impact [10]. Pregelatinized starch is a physically modified starch, which is produced through gelatinization [12]. Due to this modification, the starch can absorb and swell in cold water exhibiting improved functional and thickening properties [13]. Pregelatinized starch can be produced using techniques, such as drum-drying, spray-drying, extrusion-cooking, and microwave-heating [9]. Spray-drying is a convenient and cost-effective method for producing pregelatinized starch powder. It is highly efficient in converting liquid solutions into dry particles [14]. During this process, the solution is pumped into an atomizer, where it is converted into droplets, which are dried coming in contact with hot air [15]. Starch concentration affects the viscosity of the solution, which in turn influences the spray-drying process. The increased viscosity of the starch solution could impact droplet formation, moisture evaporation, and the formation of the microstructure during drying. As the concentration of starch increases, the starch molecules tend to arrange themselves into a crystalline form. However, during the spray-drying process, the rapid evaporation of moisture may result in the formation of an amorphous, porous structure [16; 17; 18; 19]. In the literature, there are many studies focusing on the production and characterization of physically modified starches using the spray-drying technique, such as rice starch [20], oat starch [9], sweet potato [4; 14; 21], and cassava starch [22]. Besides, numerous studies have reported that starch concentration can influence the pasting and rheological properties of starch gels [23], the viscosity of cassava starch pastes during the cooking-cooling process [24], the structure and properties of freeze-dried rice starch paste [25], and the crystallinity, enthalpy, and viscosity of cassava starch [22]. While spray-dried starches from rice and cassava have been studied, the impact of starch concentration on potato starch remains underexplored. Considering that starch concentration and viscosity play a significant role in determining the structural, morphological, and physical properties of potato starch, it is crucial to assess their impact on these characteristics in order to optimize its applications in food processing, pharmaceuticals, and biodegradable packaging. Thus, a comparative study of the structural, morphological, and functional properties of native potato starch and spray dried potato starch, as well as the impact of starch concentration on the characterization of spray-dried potato starch powders, is still lacking.