Industrial Crops and Products 38 (2012) 21–26 Contents lists available at SciVerse ScienceDirect Industrial Crops and Products journa l h o me page: www.elsevier.com/locate/indcrop Comparison of the composition of Pinus radiata bark extracts obtained at bench- and pilot-scales Carlos Bocalandro a , Verónica Sanhueza b , Ana María Gómez-Caravaca c , Julia González-Álvarez d , Katherina Fernández b,∗ , Marlene Roeckel b , María Teresa Rodríguez-Estrada e a Unidad de Desarrollo Tecnológico, Universidad de Concepción, 4191996 Coronel, Chile b Departamento de Ingeniería Química, Universidad de Concepción, 4070386 Concepción, Chile c Dipartimento di Scienze degli Alimenti, Alma Mater Studiorum-Università di Bologna, 47521 Cesena, Italy d Departamento de Ingeniería Química, Universidad Santiago de Compostela, 15782 Santiago de Compostela, Spain e Dipartimento di Scienze degli Alimenti, Alma Mater Studiorum-Università di Bologna, 40127 Bologna, Italy a r t i c l e i n f o Article history: Received 21 September 2011 Received in revised form 2 January 2012 Accepted 8 January 2012 Keywords: Antioxidant DPPH FRAP ICA Pilot scale Pine bark Scale-up a b s t r a c t Pine bark represents an interesting byproduct from the forest that can be used as a source of antiox- idants. To study the phenolic fraction of this matrix, Pinus radiata bark was extracted with a 75% ethanol solution at both bench- and pilot-scales followed by an analysis of the extraction yield variation, chemical composition (total phenolics content, tannins content, and phenol composition determined by RP-HPLC–DAD–MS and GPC) and antioxidant properties (free radical scavenging capacity, DPPH; reduc- tion capacity, FRAP; chelating activity, ICA). Extractions at bench- and pilot-scales were performed at 120 ◦ C for 120 min at a solid-to-liquid ratio of 1:20. Extract yields were not affected by the scale-up pro- cess (bench: 4.67 ± 0.14%; pilot: 4.37 ± 0.19%). No significant differences were observed in either the total phenolics content of the extracts (bench: 0.55 ± 0.01 g gallic acid /g extract ; pilot: 0.54 ± 0.01 g gallic acid /g extract ) or the tannin content (bench: 340.0 ± 7.4 mg catechin /g extract ; pilot: 334.0 ± 4.4 mg catechin /g extract ). The main low molecular weight compounds identified in the extracts were phenolic acids, catechin, epicatechin, procyanidin B-2, taxifolin and quercetin; to the best of our knowledge, we have tentatively identified syringic acid and homovanillic acid in pine bark for the first time. An increase in the average molecular weight (Mw) of the extract also changed with the extraction scale (bench: Mw = 1689; pilot: Mw = 2299). The antioxidant properties of the extracts showed a decrease in DPPH (-6.12%) and FRAP (-6.88%) and an increase in ICA (21.63%) in the pilot-scale as compared to the bench-scale extract. Based on these results, it may be technically possible to produce a polyphenolic extract from P. radiata bark at an industrial scale without extensively altering its antioxidant properties. © 2012 Elsevier B.V. All rights reserved. 1. Introduction A large number of studies have been performed to obtain and characterize vegetable extracts rich in polyphenols for directly use as antioxidants in dietary supplements for human consumption (D’Andrea, 2010; Rózek et al., 2010), and for the animal nutri- tion industry (Dschaak et al., 2011). Among other reasons, this interest is because of the growing concern about possible carcino- genic effects of chemical additives currently used as antioxidants, including TBHQ (tertiary-butyl hydroquinone), BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene) (Moch, 1986; Oikawa et al., 1998) and ethoxyquin (Błaszczyk, 2006; Błaszczyk and Skolimowski, 2007). ∗ Corresponding author. Tel.: +56 41 2661133; fax: +56 41 2243750. E-mail address: kfernandeze@udec.cl (K. Fernández). Among natural alternatives, applications of flavonoid-rich polyphenolic extracts are especially remarkable. These extracts have been evaluated for use in several dietary products to extend the product shelf life, including frozen fish (Fan et al., 2008), fresh vegetables (Martín-Diana et al., 2008), beef patties (Ba˜ nón et al., 2007) and cooked pork and beef (DeJong and Lanari, 2009). In livestock farming, the effects of polyphenols in cattle feed on meat production and organoleptic properties have been evalu- ated (Luciano et al., 2009). In addition, the use of polyphenolic extracts has also been studied, e.g., in the pharmaceutical indus- try (Lizarraga et al., 2007; Zaveri, 2006), in adhesive resins (Hoong et al., 2009) and for the removal of heavy metals (Palma et al., 2003). Polyphenolic compounds are found in a vast variety of plants, fruits and vegetables. In studies performed on different vegetable matrices (using polar organic solvents in the extraction process), pine bark extracts from several species have stood out because of their composition (Jerez et al., 2006, 2007; Ku and Mun, 2008). These extracts show a high concentration of condensed tannins, 0926-6690/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.indcrop.2012.01.001