Black chokeberry or aronia berries (_Aronia melanocarpa_) contain high polyphenol levels, providing significant antioxidant capacity [3]. Due to their high amount of antioxidant molecules, chokeberries exhibit various health effects, including antidiabetic, antioxidative, cardioprotective, hepatoprotective, anticancer properties, and even antibacterial properties [3; 4; 5]. However, chokeberries display a significant drawback related to the organoleptic properties of their juice, which frustrates consumers. Specifically, chokeberries are described as stringent, sour, and bitter due to their high procyanidin content [6]. Nowadays, these purple-black berries are being used for fresh and pasteurized juice production, for fermentation in fruit wine production, and as colorants in the food industry [6]. The application of lactic acid fermentation to chokeberry juice could be an effective alternative, targeting enriched flavor and high bioactive compounds availability. This attempt seems very interesting since it fits with the modern trend in fruit juice biprocessing [7; 8; 9], while recently, the application of lactic acid fermentation to pomegranate juice enhanced the flavor and shelf life of the fermented juice, ensuring a better control of the volatile characteristics and microbial population during storage [7]. A similar outcome was verified through the determination of increased desired volatile organic compounds (VOC), limiting in parallel the non-desired volatile compounds [10]. The multiple effects of lactic acid fermentation on the nutritional value of fruit juices has been extensively studied [7; 11; 12]. Lactic acid bacteria may modify the level and bioavailability of nutrients through their metabolism or through their interaction with the gut microbiota or even with the human immune system [7; 13]. Indeed, several phenolic derivatives showed higher antioxidant activity than their precursors after lactic acid fermentation [10; 14]. In addition to the bioconversion of phenolic compounds, lactic acid fermentation may also deliver other modifications to food ingredients, with influence on consumers health. For instance, several fruits and vegetables have been proved to exhibit higher composition of phenolic derivatives, providing in parallel high bioavailability after lactic acid fermentation with selected _Lactobacillus_ spp. [14; 15; 16]. Moreover, fruit juices have gained more attention in recent years as vehicles for probiotic delivery versus dairy products because there are more and more consumers who have shifted their interest to plant products, particularly vegetarians [13; 17; 18]. The main reasons for this turn are lactose intolerance, high cholesterol content of meat and dairy products, and allergic effects of milk proteins, which are limiting factors in the growth of dairy- or even meat-based probiotics [19; 20; 21]. In the past few years fruit juices have become very popular for probiotic delivery through lactic acid fermentation, as proposed by many researchers [18; 22; 23]. Regarding lactic acid fermentation of chokeberry juice, few research attempts have been recorded in the literature till now. Specifically, lactic acid fermentation of chokeberry juice with four different strains of _L. plantarum_ provided an alternative beverage with good polyphenols content, but without recording issues with its sensorial properties, which can be considered a significant outcome [8]. Moreover, kefir was applied in chokeberry juice fermentation resulting in increased polyphenols bioavailability as well as increased antioxidant capacity [24]. Likewise, in the frame of this research the employment of a novel potentially probiotic strain _Lactobacillus paracasei_ SP5 (now classified as _Lacticaseibacillus paracasei_) recently isolated from kefir grains [25] was studied in chokeberry juice fermentation.