**1. Introduction**

Cornelian cherry (*Cornus mas* L.) is a plant belonging to the genus *Cornus*, growing in southeastern Europe and Asia. Its fruits possess a sour tart taste, contain a single stone, and are usually eaten raw or processed as jams, liquors, vinegars, compotes, or marmalades [1–3]. These fruits are reported to contain biologically-active compounds, such as phenolic acids, flavonoids, iridoids, triterpenoids, organic acids, and vitamin C [4–6]. The ripe fruits of *Cornus mas* have usually an attractive red color, which is due to the presence of anthocyanins, plant secondary metabolites responsible for the red, purple, or blue color of fruits, vegetables, or flowers. Anthocyanins have recently drawn much attention due to their numerous health-promoting properties, such as antioxidant, anti-inflammatory, antidiabetic, antiobesity, neuroprotective, and antiatherosclerotic e ffects [7]. In Cornelian cherry fruits, several anthocyanins, such as pelargonidin and cyanidin derivatives, were identified (Figure 1). Du and Francis reported the presence of five anthocyanins: cyanidin-3- *O*-galactoside, cyanidin-3- *O*-rhamnosylgalactoside, delphinidin-3- *O*-galactoside, pelargonidin-3- *O*-galactoside, and pelargonidin-3- *O*-rhamnosylgalactoside [8,9]. Later studies indicated that Cornelian cherry fruits contain normally a mixture of three to five anthocyanic pigments identified by di fferent techniques such as high performance liquid chromatography, mass spectrometry, or nuclear magnetic resonance. The anthocyanin composition is strongly related to Cornelian cherry cultivar. Kucharska et al. confirmed the presence of five anthocyanins, delphinidin, pelargonidin, and cyanidin-3-*O*-glycosides, by investigating 26 Cornelian cherry cultivars from Poland and Ukraine [10], while Moldovan et al. reported the presence of cyanidin-3-*O*-galactoside, pelargonidin-3-*O*-glucoside, and pelargonidin-3-*O*-rutinoside in a Romanian Cornelian cherry cultivar [11].

**Figure1.**StructureofanthocyaninsfromCorneliancherryfruit.

The dietary consumption of anthocyanin-rich fruits or their derivative products may prevent numerous diseases and improve human health. Mazza et al. reported an increase in the antioxidant status of the human serum after oral intake of blueberries anthocyanins [12], although earlier studies reported that only 1% of anthocyanin compounds are present in human plasma after fruit consumption [13]. After oral administration, anthocyanins can be absorbed in stomach, as well as in intestines, either in their intact form or as metabolites [14]. After absorption, anthocyanins are transported to heart, brain, liver, kidneys, or other tissues where they can exert their antioxidant capacity and their health-promoting properties. All these results indicate that investigating anthocyanin stability in the gastrointestinal tract could deliver important information on their bioavailability and their health beneficial properties. Simulated human gastrointestinal digestion studies demonstrated that anthocyanins are rather stable in stomach, but easily degradable in small intestine mainly due to the high value of the pH [7,15,16].

The main objective of this study was to evaluate the impact of the gastrointestinal tract's biochemical conditions on the antioxidant compounds responsible for the beneficial effects on human health of Cornelian cherry fruits. Therefore, a simulated in vitro human digestion model was applied, and the stability of anthocyanins from the investigated fruits, as well as the changes in the antioxidant activity of the digested fruit extract were investigated. Although the anthocyanin profile, the total phenolic content, and the in vitro antioxidant capacity of the Cornelian cherry fruits were already elucidated by several research groups [10,11,17–21], this is the first study dealing with the impact of gastrointestinal digestion on their antioxidant activity and on the bioaccessibility of their anthocyanins.

#### **2. Materials and Methods**
