Contents lists available at ScienceDirect Industrial Crops & Products journal homepage: www.elsevier.com/locate/indcrop Pattern recognition of cardoon oil from different large-scale field trials Suzana Ferreira-Dias a, ⁎ , Jorge Gominho b , Isabel Baptista b , Helena Pereira b a Universidade de Lisboa, Instituto Superior de Agronomia, LEAF, Linking Landscape, Environment, Agriculture and Food, Tapada da Ajuda, 1349-017 Lisboa, Portugal b Universidade de Lisboa, Instituto Superior de Agronomia, Centro de Estudos Florestais, Tapada da Ajuda, 1349-017 Lisboa, Portugal ARTICLE INFO Keywords: Cynara cardunculus L. Oil content Pattern recognition techniques Triacylglycerols Sterols Tocopherols ABSTRACT Cardoon (Cynara cardunculus L.) is a spontaneous perennial thistle well adapted to the Mediterranean region, classified as a non-conventional energy crop by the EU. Large-scale field trials, using commercial grains of the same genotype, were installed for the first time in two fields in Portugal: Beja (77.4 ha) and Sesimbra (8.1 ha). In this study, the oil was extracted from composite seed samples and analysed in terms of fatty acid, triacylglycerol (TAG), sterol and tocopherol compositions. The oil content was 24.3% and 23.2% (dry basis) for samples from Beja and Sesimbra. Pattern recognition techniques (Principal Component Analysis and hierarchical Cluster Analysis) were used for sample characterization. Sample origin was correctly identified when (i) TAG profile or (ii) tocopherols and sterols compositions (bioactive compounds) were used. Sesimbra oils showed higher con- tents of the TAG LLL and PLL, while Beja oils presented higher amounts of OLL, OOL, OOO and POO. Sesimbra oils are richer in linoleic acid (63.7% vs. 59.5% in Beja) while Beja oils are richer in oleic acid (24.5% vs. 20.9% in Sesimbra). β-sitosterol (30.9% in Beja vs. 31.5% in Sesimbra) and Δ 7 -stigmastenol (31.3% in Beja vs. 30.5% in Sesimbra oils) are the major sterols. Alpha-tocopherol (111.6 mg/kg in Beja vs. 222.4 mg/kg in Sesimbra sam- ples) was the dominant tocopherol. Sesimbra oils showed higher contents of bioactive compounds and therefore, higher biological value than oils from Beja. The environmental conditions showed to be more important on cardoon oil composition than the genetic variability. 1. Introduction Cardoon (Cynara cardunculus L.) belongs to the Asteraceae family and to the Cynara genus (Franco, 1984). This perennial thistle has an annual cycle well adapted to the Mediterranean edaphoclimatic con- ditions (dry and hot summers), growing with high biomass productivity in marginal lands. Since 2005, it is classified as a non-conventional energy crop by the EU (EC Regulation n°1701/2005, Oct. 18th) fol- lowing several studies (Fernández and Manzanares, 1990; Fernández, 1998; Fernández and Curt, 1994; Lapuerta et al., 2005) namely those performed by our group under the scope of the European project “INTERREG IIIB project ‘ECAS – Energy Crops in the Atlantic Space’ (http://www.isa.utl.pt/def//interreg/). The productive crop sequence includes an initial period, for crop establishment during the first year, and the subsequent annual cycles with average production of 14 t dry biomass ha -1 y -1 (Fernández et al., 2006). The aboveground biomass (leaves, stalks and capitula) is practically dry at harvest which is a great advantage for the subsequent industrial processing (i.e. storage, transportation and transformation). Traditionally, cardoon flowers have been used as rennet for cheese making, the plant has been used as green fodder and the stalks for human consumption. Alternative utilizations for the cardoon biomass are the energy production, as raw-material for paper and pulp, oil ex- traction and for pharmacologic uses, namely the use of leaf extracts with recognized antitumoral activity (Fernández et al., 2006; Raccuia and Melilli 2007; Sengo et al., 2010; Lourenço et al., 2015; Genovese et al., 2016a). Based on encouraging results achieved in testing fields, the large- scale cultivation of cardoon as bioenergy crop was for the first time carried out with a commercial variety in two fields in the centre and south of Portugal: Beja with 77.4 ha and Sesimbra with 8.1 ha. For three years, the aerial biomass was evaluated in terms of the number and weight of capitula grains, as well as the remaining capitula residue mass. The oil from the grains of these plants was mechanically extracted with a cold press (24% of oil yield, dry basis) and used as feedstock for biodiesel production by alkali transesterification, after process optimi- zation at lab and pilot-scales (FAME yield of 97%)(Sengo et al., 2010). Cardoon oil is an unsaturated oil where linoleic acid (C 18:2 – an es- sential ommega-6 fatty acid), is the major fatty acid followed by oleic acid (C 18:1 ) and smaller amounts of stearic acid (C18:0) (Carvalho et al., 2006; Sengo et al., 2010; Raccuia et al., 2011). After oil extraction, cardoon presscake is an excellent source of protein, and can be used for https://doi.org/10.1016/j.indcrop.2018.03.038 Received 30 November 2017; Received in revised form 18 March 2018; Accepted 19 March 2018 ⁎ Corresponding author. E-mail address: suzanafdias@mail.telepac.pt (S. Ferreira-Dias). Industrial Crops & Products 118 (2018) 236–245 Available online 05 April 2018 0926-6690/ © 2018 Elsevier B.V. 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