Original Article Chemical Composition of Selected Beetroot Juices in Relation to Beetroot Production System and Processing Technology Renata KAZIMIERCZAK*, Agata SIŁAKIEWICZ, Ewelina HALLMANN, Dominika ŚREDNICKA-TOBER, Ewa REMBIAŁKOWSKA Warsaw University of Life Sciences WULS - SGGW, Faculty of Human Nutrition and Consumer Sciences, Department of Functional Food, Ecological Food and Commodities, 159c Nowoursynowska Street, 02-776 Warsaw, Poland; renata_kazimierczak@sggw.pl (*corresponding author); agatka0411@wp.pl; ewelina_hallmann@sggw.pl; dominika_srednicka_tober@sggw.pl; ewa_rembialkowska@sggw.pl Abstract Market offer of vegetable juices in Europe is growing, and the vegetable species and processing technologies used become more diversified resulting in a large range of juice types. At the same time consumers look for natural and safe products with pro-health properties. The aim of this study was to evaluate the nutritional composition of selected juices based on beetroots coming from different agricultural systems and processed according to different technologies. Research material consisted of conventional and organic juices marketed in Poland, in that pure pressed juices, fermented juice and juices from concentrate, pure and combined with apple or lemon juice. The concentration of vitamin C, organic acids, total and reducing sugars, phenolic acids, flavonoids and betalains has been determined in the juices. All beetroot juices were abundant in betalains, with higher concentrations of these compounds found in pure beetroot juices when compared to juices combined with apple or lemon. Highest concentration of betanin-3-O-glucoside was found in pure conventional juice from concentrate, while highest betanidin content was found in pure organic fermented juice. Highest vitamin C contents were found in pressed organic juices combined with apple and lemon. All juices were abundant in polyphenols, mainly phenolic acids, with highest concentrations of these antioxidants found in conventional pure pressed juice. The study shows that beetroot juices, independently on the beetroot processing technology and agricultural production system, are very valuable products due to the presence of numerous bioactive compounds, especially betalains, in their composition. Therefore beetroot juice consumption should be promoted among consumers. Keywords: beetroot juice, betalains, betanidin, betanin, organic production, phenolic compounds Available online: www.notulaebotanicae.ro Print ISSN 0255-965X; Electronic 1842-4309 Not Bot Horti Agrobo, 2016, 44(2):491-498. DOI:10.15835/nbha44210372 Introduction Vegetables and fruit have an important role in the human diet, and increasing of their consumption is recommended by WHO/FAO and by nutritional experts around the world (WHO, 2003). Sufficient daily consumption of these products could help prevent major diseases, such as cardiovascular diseases and certain cancers (Key, 2011; Wang et al ., 2014). A very important group of products in this context are the processed fruit and vegetables, and vegetable juices among them. The market offer and the availability of these products are getting wider (AIJN Liquid Fruit Market Report, 2015). These allow both to expand the consumption of vegetables, and at the same time to enlarge the intake of their bioactive components during the year. Therefore, nutritionists recommend increasing consumption of vegetable juices instead of replacing natural products with synthetic vitamin-mineral supplements (Liu, 2013). Drinking vegetable juice is one of the ways to increase a dose of essential microelements, vitamins and other antioxidants as well as fiber delivered to the organism (Groele, 2010). Vegetable juices are more easily assimilated in an organism than fresh vegetables, as the squeezing process destroys the fiber structure and releases bound phytonutrients (Rakin et al ., 2004). Market offer of vegetable juices in Poland is growing, and the vegetable species, as well as the processing technologies used, become more diversified, resulting in a large range of juice types (Wołosiak and Miłosz, 2012). Beetroot is one of the valuable vegetables in terms of nutritional value and i s increasingly used for juice production. Poland is the largest EU producer of beetroots, with the share of beetroots in the general vegetable harvests reaching nearly 67% (Eurostat, 2016). In recent years, with the increase in Received: 15 Apr 2016. Received in revised form: 09 Nov 2016. Accepted: 11 Nov 2016. Published online: 14 Dec 2016.