## 1 Introduction
Many essential compounds, such as polyphenolsand flavonoids, suffer from poor solubility and stability, limiting their absorption in the human body. Research has demonstrated that \(\gamma\)-PGA can significantly enhance their solubility, thereby increasing their functional efficacy in food formulations [18]. \(\gamma\)-PGA has also been used as an additive to food products with a high content of mineral components in order to accelerate their absorption in the small intestine [19]. Beyond its nutritional benefits, \(\gamma\)-PGA plays a crucial role in improving the texture and shelf life of functional foods. It can be used to prevent ageing of starch-based bakery products and pasta, and to improve their texture as well as to enhance the rheological and thermal properties of wheat dough [20]. Its high water retention capacity and gel-forming properties allow it to also function as a stabilizer and texture modifier of other food products, helping maintain their consistency and structural integrity. This property makes it particularly valuable in the formulation of plant-based and processed foods, where moisture balance and stability are critical factors [21]. Another promising application of \(\gamma\)-PGA lies in its ability to reduce off-flavors and mask the extraneous taste of plant-based foods [22]. Many plant-derived protein products and frozen foods often have undesirable bitter notes, which can affect consumer acceptance. \(\gamma\)-PGA has been found to effectively mask these off-flavors, making plant-based alternatives more palatable without the need for artificial additives [7]. Due to biologically and environmentally beneficial features of \(\gamma\)-PGA, such as increasing the resistance of plants to salt or drought stress (by remarkably increasing the activity of plant antioxidant enzymes), the product is currently applied to many plant cultures to reduce the use of chemical fertilizers and to reduce the overall effects of agricultural pollution. Thus, \(\gamma\)-PGA seems to be an attractive agent in the development of green agriculture [23; 24]. Overall, \(\gamma\)-PGA presents a multifunctional approach to improving functional food systems. Whether through enhancing bioavailability, optimizing texture and stability, masking undesirable flavors, acting as a natural preservative, or supporting agricultural sustainability, its applications highlight its potential as a valuable ingredient in the evolving landscape of functional and health-oriented foods. As far as we know, our experiment is the first ever to describe the use of \(\gamma\)-PGA in the cultivation of kale and lupin sprouts. The increasing popularity of sprouts from the _Brassicaceae_ family is caused by their nutritional and medicinal properties resulting from the content of compounds such as glucosinolates (GLS) and phenolic compounds. They have cytotoxic, antimicrobial, and antioxidant properties [25; 26]. For this reason, sprouts are classified as functional foods [27]. Factors that influence the concentrations of bioactive compounds in sprouts include a specific variety, development conditions, and exposure to environmental stress [26]. Phytochemicalals such as glucosinolates and different polyphenic compounds occur in the highest doses in the initial days of the germination process, in quantities much higher than in mature plants [26]. One of the representatives of the _Brassicaceae_ family that is the source of the above-mentioned compounds is kale--_Brassica oleracea_ var. _sabellica_. It belongs to the group of dark green vegetables, headless cabbage, and is characterized by the presence of leaves along the stem. Kale is a valued plant in agriculture due to its simple cultivation, low costs, and resistance to unfavorable environmental conditions [28]. Kale is distinguished by its rich GLS content and, therefore, the various health properties described above. Moreover, it has antimicrobial activity against, among others, _Enterococcus faecalis_ and _Staphylococcus aureus_[29].