## 1 Introduction  
Recently, the so-called convenience food has become very popular in the market [1]. At the same time, there is a trend to reduce the consumption of meat and animal products, and consumers are looking for vegan products that they can use in the traditional way they are familiar with [2]. Such products also include plant-based sausages (PBSs), which can be used both as part of the main course (e.g., a hot dog) and as a snack. Vegan food producersare making them more and more similar to their meat counterparts. However, it should be remembered that animal products are a rich source of exogenous amino acids and iron [3; 4; 5], while plant products are unfortunately often characterized by a lower nutritional value. Thus, designers of vegan food must remember to supplement it with nutrients deficient in a plant-based diet, such as iron, vitamin B\({}_{12}\), or essential unsaturated fatty acids [6; 7]. The development of PBSs has seen significant progress, with innovations in ingredients and additives aimed at improving their nutritional profile, sensory attributes, and shelf life [8; 9]. Recent advancements include the incorporation of a variety of ingredients and additives, which are critical for enhancing the functional properties of PBSs. A multitude of studies have investigated the role of plant proteins in vegan sausage. Soy protein isolates, pea protein, and wheat gluten are among the most common protein sources used [10; 11; 12]. Research has demonstrated that soy protein isolates can significantly improve the textural properties of vegetable sausages, providing a more meat-like mouthfleel [13; 14]. Similarly, pea protein has been shown to enhance moisture retention and the overall juiciness of the product [15; 16]. Among the new proteins gaining popularity is potato protein (PP). It is a by-product obtained from potato juice during the starch production process [17]. Research has shown that potato protein has a very high nutritional value and may also serve as a source of iron and biologically active compounds that have beneficial effects on the course of gastrointestinal diseases [18]. A study conducted in vitro demonstrated that PP exhibits significant antioxidant properties comparable to those of butylated hydroxytoluene. Additionally, TBARS (thiobarbituric acid reactive substances) assay revealed that elevated levels of patatin may help limit the oxidation of low-density lipoprotein [19]. PP has exceptional nutritional benefits and contains 19 amino acids, including lysine, methionine, threonine, and tryptophan [20]. It is highly digestible and features a well-balanced amino acid profile, making it comparable to the proteins found in eggs and milk [21]. PPs have unique physicochemical properties owing to their ability to form highly stable foams and emulsions [22]. Moreover, the use of the enzyme alcalase for the hydrolysis of PP can enhance overrun and increase oil absorption [23]. The combination of different plant proteins, including potato proteins, has been shown to enable the optimal functional properties of vegan sausages to be obtained. Products containing protein blends, such as those combining potato protein with pea or wheat gluten proteins, exhibit superior textural and functional properties compared to those formed with single-source proteins. This approach leverages the complementary functional attributes of various proteins to achieve a more favorable product profile. In vegan sausage production, various plant-based fats are used to achieve the desired texture and flavor. Commonly used fats include coconut oil [24], which provides a solid texture and rich mouthfeel; palm oil [25], known for its neutral flavor and solid consistency, although its use can be controversial due to environmental concerns [26]; sunflower oil [27], which offers a light flavor and high smoke point; canola oil, chosen for its neutral taste and health benefits [28]; and soybean oil, valued for its mild flavor and functional properties [29].