Contents lists available at ScienceDirect Journal of Functional Foods journal homepage: www.elsevier.com/locate/jff Chemical composition and biological activities of Juçara (Euterpe edulis Martius) fruit by-products, a promising underexploited source of high-added value compounds Jéssica A.A. Garcia a,b , Rúbia C.G. Corrêa a,b,c , Lillian Barros c , Carla Pereira c , Rui M.V. Abreu c , Maria José Alves c , Ricardo C. Calhelha c , Adelar Bracht a,b , Rosane M. Peralta a,b, ⁎ , Isabel C.F.R. Ferreira c, ⁎ a Department of Biochemistry, State University of Maringá, Paraná, Brazil b Graduate Program in Food Science, State University of Maringá, Paraná, Brazil c Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal ARTICLE INFO Keywords: Euterpe edulis Residue Nutritional value Antioxidant potential Antimicrobial activity Phenolic compounds ABSTRACT The pulp of the fruits of Juçara (Euterpes edulis Martius), a native tree of the Atlantic Rainforest of Brazil, is widely consumed thanks to its flavour and nutritional value. The industrial production of Juçara fruit pulp generates solid residues (peel) which are usually discarded. In this work, a hydroalcoholic extract from Juçara peel flour was evaluated for its phenolic profile as well as for its bioactivities. A total of nineteen phenolic compounds were identified in the Juçara peel flour. Among these, seventeen were non-anthocyanin phenolic compounds, namely two phenolic acids, four flavanonols, six flavones, and five flavonols; whereas the two anthocyanin molecules were cyanidin glycoside derivatives. The Euterpe edulis peel flour presented antioxidant activity and antibacterial potential but was not hepatotoxic. These observations corroborate the idea that this by- product could fit well into the circular bioeconomy concept, thus promoting the Juçara fruit production chain. 1. Introduction Euterpe edulis Martius, popularly known as Juçara, is a native tree of the Atlantic Rainforest found predominantly in the states of the southern and southeastern regions of Brazil (Schulz, Borges, Gonzaga, Costa, & Fett, 2016). It produces a noble type of palm heart and much appreciated berries (Fig. 1). The palm hearts are largely consumed and of economic relevance in Brazil, presenting superior quality and flavour compared to other species of the genus Euterpe (Borges et al., 2013). In turn, the Juçara fruit is a globose berry that weighs about 1 g (90% of which corresponds to the single seed) that, when ripe, acquires a dark purple shade that closely resembles the fruits of Euterpe oleracea Mart. and Euterpe precatoria Mart. employed in the production of açaí (Schulz et al., 2017). However, the E. edulis fruit has a sweeter taste than these last two, being very appreciated by açaí consumers (Felzenszwalb, da Costa Marques, Mazzei, & Aiub, 2013). Several authors have demonstrated the exceptional nutritional characteristics of Juçara berries and described their main bioactive constituents, such as flavonoids, especially anthocyanins, and phenolic acids, to which their antioxidant activity is attributed (Inada et al., 2015; Schulz et al., 2016; Vieira, Marques, Machado, Silva, & Hubinger, 2017). The extraordinary antioxidant potential of E. edulis fruits has been largely confirmed in in vitro (Bicudo, Ribani, & Beta, 2014; Cardoso et al., 2015; Schulz et al., 2015), ex-vivo (Borges et al., 2013) and in vivo studies (Freitas et al., 2016). Furthermore, a clinical trial verified that the Juçara juice consumption had a very positive action on the antioxidant status and cellular oxidative damage of healthy vo- lunteers (Cardoso et al., 2015). In recent years, the Juçara pulp has been applied as a substrate for probiotic bacteria fermentation (Guergoletto, Mauro, & Garcia, 2017). The incorporation of this in- gredient in yogurt formulation enhanced the nutritional status of the product as well as the probiotic resistance to simulated gastric and enteric conditions (Geraldi, Tulini, Souza, & De Martinis, 2018). Juçara berries are almost exclusively commercialized as frozen pulp, which is consumed as such or used as the main ingredient of various cold beverages and ice creams (Schulz et al., 2016). For com- mercial application, the fruits are macerated and blended with different amounts of water in a depulping apparatus, where the epicarp and mesocarp are separated from the seeds. Consequently, the industrial production of Juçara pulp generates solid residues and effluents, which https://doi.org/10.1016/j.jff.2019.02.037 Received 19 December 2018; Received in revised form 11 February 2019; Accepted 17 February 2019 ⁎ Corresponding authors at: Department of Biochemistry, State University of Maringá, Paraná, Brazil (R.M. Peralta). E-mail addresses: peralta@uem.br (R.M. Peralta), iferreira@ipb.pt (I.C.F.R. Ferreira). Journal of Functional Foods 55 (2019) 325–332 Available online 02 March 2019 1756-4646/ © 2019 Elsevier Ltd. All rights reserved. T