## 1 Introduction  
Several studies concerning the gluten-free bread (GFB) available on the market have shown low levels of protein and micronutrients and high levels of lipid and sodium compared to similar products made with wheat flour. These features, in addition to the lack of enrichment or fortification, negatively contribute to the health of individuals with a gluten-restricted diet [1, 2, 3, 4, 5, 6]. Our recent overview showed that over the last ten years, multiple gluten-containing (GC; n = 7122) and gluten-free (GF; n = 3153) food products have been investigated and compared worldwide [1]. Results for GFB (n = 935) show that it is composed of numerous raw ingredients and additives that result in an extensive variability in the contents of carbohydrates (14-84%), fat (1-19%), proteins (0-11%), sugar (0-24%), and dietary fiber (0-17%). These products are still recognized as being high in fat, low in protein content, and, in some cases, also low in dietary fiber.  
In addition to the lack of nutritional content, GFB is generally recognized as a product with poor texture, dry mouthfeel, and poor taste [1; 5; 6]. Therefore, sensory and nutritional aspects are key issues to be addressed in the development of healthier GFBs that can meet quality requirements [1].  
To address this problem, the use of alternative raw materials, such as whole-grain sorghum flour (SF), which is rich in nutrients and bioactive compounds, has been recommended [1]. Originating in Africa, sorghum is the fifth most-produced cereal worldwide [7]. Sorghum has a high potential for grain production in addition to its extraordinary ability to withstand environmental stresses, making it an excellent option for grain production in water deficit situations and low soil fertility [8]. Compared to other cereals, such as oats, rice, and wheat, sorghum has higher concentrations of total phenolic compounds, such as tannins, showing a greater antioxidant capacity [9; 10]. Sorghum also stands out as a good source of dietary fiber, iron, phosphorus, magnesium, and zinc [11].  
Researchers have reported good results in terms of the physical properties of GFB made from sorghum flour (SF) alone or blended with other non-gluten flours or starches [12; 13; 14]. Authors have also shown the potential of sorghum to develop food products with a sensory and nutritional appeal since these products made with SF were well accepted by consumers and can contribute to human health [15; 16]. GFB made with SF had higher protein, dietary fiber, total phenol contents and higher antioxidant properties than GFB prepared with rice flour (RF), which is one of the main ingredients used in commercial GFB [6; 17]. However, most studies have been conducted with bronze sorghum (BS), and it is also important to evaluate the potential of other varieties, such as white sorghum (WS).  
The literature has shown the need to increase the water content of GFB formulations enriched with dietary fiber and/or protein or with other raw materials that are sources of these components because of the high water retention capacity of these ingredients. Increasing the water content is important to ensure appropriate conditions for the dough viscosity, starch gelatinization, and protein denaturation during the breadmaking process [18]. The amount of water must be individually adjusted for each formulation while considering the proportion of ingredients in the formulation and the process conditions. In recent publications, a maximum of 120% water (flour weight basis) was used in GFB formulations using up to 70% sorghum flour [13; 14; 15; 16; 19; 20]. Investigation of higher sorghum and water content levels has not been often explored. Therefore, the present study aimed to investigate whether increased water content allows the use of higher levels of whole-grain SF to obtain GFB with better nutritional, physical, and sensory properties.