## 1 Introduction  
The bread manufacturing industry has made remarkable progress regarding the application of novel biotechnology and other technologies, targeting the satisfaction of consumers' requests for healthy and high-nutritional-value products [1, 2]. Likewise, several research studies have focused on the enhancement of the nutritional value of bread [3]. In this vein, an upgraded protein content, enhanced antioxidant activity, a high load of bioactive compounds and longer preservation times, among other factors, are the main targets. Interestingly, vegetable- and fruit-derived materials have been studied in bread production, such as carrot [4], mango peel [5], chokeberry fruit [6], apple [7], banana [8], pomerangate peel [9], orange peel [10, 11] and apple pomace, most of them in the form of dried powder. The outcomes were very promising, since fruits contain respectable amounts of fibers, minerals, vitamins, polyphenols, carotenoids and glucosinolates, comprising high nutritional value and simultaneously delivering healthy benefits. In addition, fruits do not contain gluten and can be easily applied in various formulations in gluten-free breads. However, drawbacks may appear in terms of the quality attributes of bread, such as the deterioration of sensorial and physicochemical properties [6; 12]. Thus, the evaluation of proper formulations and an adequate concentration of all the ingredients in bread production is crucial in order for most of the quality parameters (nutritional value, physical properties and shelf life) to be in balance and finally be accepted by consumers. Recently, Cornelian cherry (_Cornus mus_ L.) was applied as a powder in the formulation of bread production, where the proper addition (0, 1, 2, 5 and 10% \(w/w\)) into wheat flour improved the physical properties of the produced bread and did not affect the sensorial characteristics of the bread [13]. It is a very good source of sugars, organic acids, anthocyanin and phenolic compounds; it has antibacterial and radioprotective properties against several pathogens and exhibits antihistamine, cytotoxic, anti-malarial and anti-inflammatory effects [14]. It was applied as a substrate in functional fruit juice production through fermentation by probiotic _Lactobacillus plantarum_ ATCC 14917, leading to a product with high amounts of probiotic bacteria and significant nutritional properties [15]. The same outcome was found when the _L. paracasei_ K5 strain, either free or immobilized on delignified wheat bran, was used for fermentation [16]. Likewise, the strategy of applying fermented fruit juices via LAB in freeze-dried powdered form seems quite interesting. Recently, a supplement containing freeze-dried fermented pomegranate juice via probiotic _L. plantarum_ ATCC 14917 was successfully applied in sourdough bread making, leading to a final product with (i) improved nutritional quality in terms of total phenolic content (TPC), antioxidant activity (AC) and phytate reduction, (ii) longer preservation times and (iii) accepted sensory properties [17]. This specific work was a challenge in terms of examining the same strategy in the same conditions while replacing only the fruit juice (Cornelian cherry instead of pomegranate juice), not just for comparing these two fermentation systems but primarily investigating the consistencies of this form of Cornelian cherry supplement in sourdough bread's properties. For instance, even though Cornelian cherry was applied as a powder in the formulation of bread production [13], in the current study, (i) Cornelian cherry was applied in its fermented form, while (ii) sourdough technology was used and not direct bread making technology (based on baker's yeast). The aim and perspectives of the current study are presented in Figure 1, which are dealing with the examination of, for the first time, (i) unfermented Cornelian cherry juice and (ii) fermented Cornelian cherry juice via _L. plantarum_ ATCC 14917 as novel, nutritious supplements.