# Modification of Mineral Content in Bread with the Addition of Buckwheat Husk
## 1 Introduction  
The growing consumer demand for health-promoting foods has led the baking industry to focus on fortifying and improving the nutritional quality of baked products by incorporating natural, nutrient-dense ingredients [1]. Food fortification, which has been utilized as a public health strategy to increase nutritional intakes over the last century, has effectively reduced the risk of nutrient deficiency illnesses [2]. Bread is one of the most popular foods consumed by the majority of people around the world. Most bread manufactured with refined flour is low in minerals, vitamins, fiber, and antioxidants since bran and germ are removed during grain manufacturing, milling, and grinding processes. Furthermore, bread dough requires a heating procedure to improve digestibility, palatability, and physical and nutritional qualities, resulting in further decreases or losses of bioactive components. As a result, bread can be low in nutrients and does not meet consumers' nutritional and health requirements. The success of bread as a basic food can be attributed to two key factors: its ease of preparation and component selection, as well as the variety of grains that can be used in its production. The fundamental ingredients of bread are flour, water, yeast, and salt, which are combined, fermented, and baked to create bread. Breads available on the food market differ in composition and nutritional value. Particularly, wholegrain bread is an important source of dietary fiber, minerals, B-group vitamins, complex carbohydrates and proteins. Improving bread composition in terms of functional components, such as protein, fiber, minerals, vitamins, and antioxidant content may offer additional health benefits for customers, as well as give marketing opportunities for food manufacturers in a competitive retail scenario [3; 4; 5]. In addition to well-known plant-based additives such as sunflower seeds, caraway seeds, pumpkin seeds, flax seeds and fruit additives, breads with unusual, new additives such as nigella, chia seeds and even vegetable additives (carrot, tomato, betroot or broccoli) have also found places in commercial offerings [6]. These additives increase the levels of minerals in bread to a degree depending on their content of a specific raw material. For example, [PERSON] et al. [7] showed that bread with 10% pumpkin seed flour had a 6.7 times higher iron content (8.98 mg/kg) compared with the control (1.34 mg/kg). Additionally, the contents of magnesium, phosphorus, and zinc increased with higher levels of pumpkin seed flour substitution, with zinc increasing from 5.09 mg/kg in the control to 12.7 mg/kg in bread with 10% pumpkin seed flour. [PERSON] et al. [8] observed significant (\(p<0.05\)) increases in Fe, Mg, Ca and K in breads fortified with 20% and 40% additions of fresh spinach. The most spectacular increase was reported for Ca--73% and 97%--and K--52% and 116%--in breads with 20% and 40% spinach addition, respectively, compared with the control. The same authors [8] proved that a 20% addition of fresh kale to bread dough significantly (\(p<0.05\)) increased the levels of Mn, Fe, Mg, K and Ca in the final product. In the study of [PERSON] et al. [9], the effect of adding other vegetables on bread mineral composition was tested. The highest increase was reported for Ca, ranging from 51% to 113% in bread samples enriched with 10% and 20% carrot and pumpkin powders. In terms of microelements, the addition of these powders to wheat bread caused the largest changes in Cu (46-150% increase) and Mn (25-99% increase) contents. An interesting and innovative additive to bread that does not require cultivation and can be obtained very easily is buckwheat husk. It is a byproduct obtained in large quantities during the production of buckwheat groats. It is popular in many countries, and its purchase and storage are more economical and convenient than the plant additives discussed above.