## 1 Introduction  
According to 2023 estimates, colorectal cancer (CRC) is the third most commonly diagnosed cancer and the third leading cause of cancer deaths worldwide [1]. CRC also belongs to the group of cancers where there is a strong correlation between incidence and lifestyle, which includes high alcohol consumption, smoking, excess body weight and an inappropriate diet [2]. In the context of diet, a factor that concerns every human being, numerous reports have shown the enormous potential of natural products rich in phenolic compounds. The use of phytochemicals in the prevention and/or treatment of cancer has been a subject of discussion for centuries. Currently, anticancer activities have been demonstrated for over 3 thousand plant species and 30 plant-derived compounds have been qualified for preclinical studies [3, 4]. Plant secondary metabolites have been shown to activate and/or inhibit multiple signaling pathways that lead to CRC cell death [5]. Therefore, the purification of plant products from phenolic compounds and the demonstration of their activity in in vitro and in vivo models could lead to the development of effective methods of controlling and treating CRC. However, one of the greatest limitations of usingthe properties of phenolic compounds is the low bioavailability and limited tissue distribution [3; 6]. To overcome the above-mentioned challenges, the use of microcapsules has been widely discussed in the last decade. The formation of microspheres via ionotropic gelation allows for the binding of phytochemicals, which ensures improved stability, increased bioavailability, and actual bioefficacy at the target site. In a study conducted by [PERSON] et al. [7], pH-sensitive alginate microcapsules were developed, showing the highest degree of release of 5-fluorouracilacil (anticancer drug) in the large intestine, which proved that they could be effectively used for the targeted delivery of anticancer drugs to the colon. Natural polymers, such as alginate (Alg), are among the most commonly used carriers due to their properties, such as low cost of acquisition, low toxicity, ease of physicochemical modification, and high biocompatibility and biodegradability. The greater ability of Alg to bind phytochemicals can be achieved by adding, among others, pectin (Pect) [8], whey protein isolate (WPI) [9], chitosan [10], carrageenan [11], cellulose [12], gum Arabic [13], zein [14] and psyllium mucus [15]. The selection of the encapsulating mixture, as well as the form of core preparation, may play a key role in the encapsulation process, the bioavailability of compounds, and encapsulation efficiency. In our previous studies, we showed that among the analyzed phenolic fractions isolated from 10 different berries, the highest CRC-targeting potential was demonstrated by the extract from blueberry fruit (_Vaccinium myrtillus_ L.) [16]. Previous studies have shown the ability of blueberry extracts to inhibit CRC cells through DNA fragmentation, which indicates the promotion of cell apoptosis [17; 18]. In the cited works, the proven activity against CRC cells was attributed to the content of phenolic compounds. In general, anthocyanins dominate in blueberry fruits, which can constitute up to 95% of all polyphenols identified in the quantitative profile. The dominant compounds of this group include cyanidin 3-\(O\)-glucoside, cyanidin 3-\(O\)-arabinoside and peonidin 3-\(O\)-galactoside. Other groups of compounds identified in blueberry fruit extracts include the following: flavonoids (such as quercetin 3-\(O\)-glucose) and phenolic acids (chlorogenic acid) [16; 19]. The content of phenolic compounds in extracts depends significantly on the method used to obtain them, which may translate into their anticancer properties. So far, microcapsules with blueberry fruit extracts have been obtained mainly via spray and freeze-drying [20; 21; 22; 23]. However, there are a negligible number of reports on the production of microcapsules via ionotropic gelation. Only [PERSON] et al. [24], [PERSON] et al.