The extent of these alterations is heavily dictated by the inherent composition of amylose-amylocetin in starch and the presence of non-starch constituents in flours such as proteins, phenolic compounds, lipids, and minerals. During treatment, these constituents potentially interact with starch, impacting aspects like solubility and crystallinity. The modification's extent and the resultant functional attributes are influenced by factors such as temperature, moisture content, and the duration of the hydrothermal treatment. Varying these conditions causes diverse effects on starch and flour. Furthermore, hydrothermal modifications can influence molecular arrangements and the dynamics between starch granules, encompassing both intra- and inter-granule interactions, which are crucial in defining the functional properties of the modified starch and flour. The source of the starch or flour, be it potato, rice, mung beans, or sweet potato, also plays a pivotal role in determining the specific impacts of hydrothermal modifications on their functional properties. Each source possesses unique characteristics that interact distinctively with the modification process. Moreover, the number of hydrothermal modification cycles can also have a bearing on the functional attributes of starch and flour, with multiple cycles potentially leading to varied effects compared to a single cycle [20; 21; 22; 23; 24; 25; 26; 27; 28]. Electromagnetic fields, especially the microwave spectrum, serve as very efficient energy transmitters [29; 30]. The microwave radiation absorption capacity of flour, the moisture change during the treatment, the particle morphological structure, the crystallinity/amorphous region ratio, and flour thermal properties were studied, revealing a significant gelatinization temperature rise and the amylopectin retrogradation extent in treated-flours [31; 32; 33]. The treatment resulted in lower viscometric profiles, amylose retrogradation, and higher pasting temperatures [31; 32; 33]. Hydrothermal treatment via microwave radiation has been shown to improve the viscoelastic properties of teff and buckwheat flours and resulted in increased particle size, hydration properties, and stability of starch crystallites [34; 35]. These findings suggest that hydrothermal treatment via microwave radiation can enhance the viscoelastic properties of teff and buckwheat flours, making them potential ingredients for improving the technological, nutritional, and sensory quality of food products. Common buckwheat was chosen as it is one of the most popular gluten-free raw material for Poland and Ukraine; attempts have also been made to try and introduce this buckwheat into other regions, including Spain. Teff is a very nutritious minor crop with low agricultural demands; as a result, there is widespread demand for teff as part of wider biodiversity improvement initiatives. The rheological characteristic of two different common buckwheat flours and two different varieties of teff flour were studied after undergoing the microwave treatment with different initial moisture contents (30%). The resulting gels were evaluated for pasting, viscoelastic, and textural characteristics after preparation and after 3D extrusion-based printing.