## 1 Introduction  
Vegetarian diets are becoming increasingly popular and are perceived as healthier and beneficial to the consumer's health. They are based primarily on products of plant origin, including fruits, vegetables, legumes, nuts, seeds, and grains. A characteristic feature of vegetarian diets is the exclusion of meat, fish, seafood, or animal offal [1]; however, some vegetarian diets allow for the consumption of dairy products and eggs [2]. The reasons for the spread of this way of eating on a global scale are mainly ethical, ecological, and economic motivations, religious beliefs, the influence of the environment and culture, as well as health benefits [1]. Even though vegetarian diets are credited with many beneficial properties affecting human health, there are still concerns about the completeness of this restrictive dietary pattern. There is a belief that these diets do not provide enough nutrients such as protein, calcium, iron, zinc, or vitamin B\({}_{12}\)[3]. Due to its high nutrient content, soy is a plant most often consumed in vegetarian diets. The health-promoting properties of soybean are largely influenced by numerous bioactive components [4]. The dry matter of soybean contains approximately 40% protein, 20% fat, approximately 35% carbohydrates, and 5% ash [5]. Soybean protein provides a high lysine content compared to other plant proteins. Carbohydrates found in soybeans include starch, which occurs in significant amounts, indigestible, soluble sugars (stachyose, raffinose, and sucralose), and insoluble fractions of dietary fiber (cellulose and hemicellulose) [6]. Soy also provides significant amounts of vitamins (A, E, B\({}_{1}\), B\({}_{2}\), B\({}_{6}\), C) and minerals (nitrogen, potassium, magnesium, iron, calcium, phosphorus). Tofu, i.e., soybean curd obtained by coagulation of soy drink, is the most popular high-protein, non-fermented soy product [7]. The supernatant resulting from the coagulation process of soy protein using citric acid, calcium chloride, calcium sulfate, magnesium chloride, or gluconolactone is removed, and the cheese is transferred to perforated containers and pressed to obtain uniform blocks [8]. Depending on the final water content and the type of coagulant, the product may have a different structure. Coagulation using calcium sulfate leads to a product with a highly granular structure, while using magnesium compounds contributes to obtaining tofu with a gel structure [8]. In Southeast Asian countries, tofu is one of the basic ingredients of cuisine, known for over two thousand years [9], but in European countries, it is already becoming more and more popular. Tofu is consumed primarily for its numerous health and nutritional properties [10]. Regular consumption of tofu reduces the risk of developing some chronic diseases, such as cancer, cardiovascular diseases, and osteoporosis [8; 11; 12]. It is rich in isoflav and has anti-atherosclerotic effects [9]. Attempts were made to increase the content of compounds from this group by introducing microencapsulated isoflavuce extract into tofu [13]. Consuming soy protein found in tofu effectively reduces the concentration of total serum cholesterol, LDL cholesterol, and triglycerides compared to animal protein [9]. Although processing soybeans into tofu reduces the amount of isoflavnes from 1267 mg in soybeans to 455 mg per gram, this amount is sufficient to provide health benefits [14]. Due to the presence of high moisture and protein, tofu spoils within 1-3 days without the use of any preservation method, and the spoiling microorganisms, such as lactic acid bacteria, _Escherichia coli_, and _Pseudomonas_ species, were mainly reported [8; 15]. Thus, various preservation methods have been explored to increase the shelf-life of tofu by reducing the microbial load or inhibiting microbial growth [16].