## 1 Introduction  
Lately, there has been a great need for the development of innovative food products possessing many positive health benefits, such as antioxidative, antidiabetic and anti-inflammatory effects [1]. The modern, busy lifestyle has a large impact on eating habits which can lead to a negative impact on health. Quite often, food is related to the fulfillment of desire, and a balance between pleasure and health has to be found [2]. Due to these reasons, functional foods are gaining more attention from consumers; however, their attractiveness cannot be neglected. Cherries are a rich resource of polyphenols and other bioactive food components, including fibers, vitamin C, carotenoids and potassium. There are two main types of cherries, sweet cherries (_Prunus avium_ L.) and tart cherries (_Prunus cereus_ L.). Most of the sweet cherries are consumed fresh, while 97% of tart cherries are processed into different products for direct consumption or baking or cooking [3]. Natural polyphenols present in fruits and vegetables have poor stability, can be easily degraded and are sensitive to light, heat and oxygen. The application of polyphenols in food products is also limited as a result of their unpleasant taste and formation of off-color [1]. From this perspective, there is a need for the development of alternatives that minimize the nutritional and sensory losses while achieving greater stability of polyphenols [4]. Considering the structural and functional varieties of proteins, different approaches of exploiting proteins for the delivery of bioactives have been recommended [1]. It has been reported that protein-based aggregates provide a protective effect on polyphenols. For instance, the antioxidant activity of proteins increased after modification with certain polyphenols [5]. However, interactions between proteins and polyphenols are various and complicated since they both show high sensitivity to the environment [6]. Larger polyphenols have been reported to form complexes with dairy proteins. This binding can influence the electron donation capacity of polyphenols through a reduction in the number of hydroxyl groups available in the mixture. Caseins are major phosphoproteins of mammalian milk and belong to the group of unstructured proteins with unfolded structure and low hydrophobicity under native conditions [7]. Cyanidin-3-rutinoside, cyanidin-3-glucosyl-rutinoside and cyanidin-3-glucose are anthocyanins detected in tart cherries, while the most abundant of the phenolic acids is chlorogenic acid [8]. It has been reported that there is a strong relationship between anthocyanin intake and anti-inflammatory activity, protection against neurological diseases and reduction of heart disease, obesity and diabetes. In the food industry, anthocyanins have the potential to be used as natural dyes, as synthetic dyes can cause adverse effects [4]. As consumers' awareness of the significance and advantages of a healthy diet is on the rise, the use of tart cherry in the development of functional foods is necessary [9]. In the review of [PERSON] et al. [10], the importance of protein/polyphenol particles and their possible utilization in the food industry, as well as the bioaccessibility of bioactive polyphenic compounds and edible proteins were explored. In the food industry, depending on their properties, proteins have a broad range of applications. They can be used as emulsifiers, stabilizers of foams and colloid systems and film-forming polymers [11; 12]. In the past decade, their utilization as microencapsulating carriers of different active compounds has been the focus of many studies, and an especially distinct segment is the encapsulation of phenolics. In this way, stability of phenolics can be achieved and bioactive protein-based aggregates can be formulated [13; 14; 15; 16; 17; 18]. Usually, during the formulation of protein-based aggregates, when fruit material is used as a resource of phenolic compounds, the adsorption of flavor compounds has been neglected.