Effect of natural antioxidants in Spanish salchichón elaborated with encapsulated n-3 long chain fatty acids in konjac glucomannan matrix P.E.S. Munekata a,1 , R. Domínguez b , D. Franco b , R. Bermúdez b , M.A. Trindade a,1 , Jose M. Lorenzo b, ⁎ a Department of Food Engineering, College of Animal Science and Food Engineering, University of São Paulo, 225 Duque de Caxias Norte Ave, Jardim Elite, 13.635-900 Pirassununga, São Paulo, Brazil b Centro Tecnológico de la Carne de Galicia, rúa Galicia n° 4, Parque Tecnológico de Galicia, San Cibrao das Viñas 32900, Ourense, Spain abstract article info Article history: Received 18 March 2016 Received in revised form 3 November 2016 Accepted 4 November 2016 Available online 05 November 2016 The effect of natural antioxidants on physicochemical properties, lipid and protein oxidation, volatile compounds and free fatty acids (FFA) were determined in Spanish salchichón enriched with n-3 fatty acids encapsulated and stabilized in konjac matrix. Phenolic compounds of beer residue extract (BRE), chestnut leaves extract (CLE) and peanut skin extract (PSE) were also identified and quantified. Five batches of salchichón were prepared: control (CON, without antioxidants), butylated hydroxytoluene (BHT), BRE, CLE and PSE. The main phenolic compounds were catechin and benzoic acid for BRE, gallic acid and catechin for CLE and catechin and protocatechuic acid for PSE. Statistical analysis did not show significant differences on chemical composition among treatments. Reduc- tions in luminosity (P b 0.05) and pH (P b 0.001) were observed with the CLE batch, whereas the other colour parameters were not affected by the addition of natural antioxidants. Finally, the inclusion of antioxidants (P b 0.001) decreased the hexanal content, whereas the FFA content increased by the addition of natural extracts. © 2016 Elsevier Ltd. All rights reserved. Keywords: Natural antioxidant Phenolic compounds Lipid and protein oxidation Microencapsulated fish oil Sausage 1. Introduction The intake of n-3 long-chain fatty acids is of great importance due to the positive role in infant development, mental illness and the preven- tive effect against cardiovascular diseases (Riediger, Othman, Suh, & Moghadasian, 2009). In a previous study, Lorenzo, Munekata, Pateiro, Campagnol, and Dominguez (2016) observed that the incorporation of microencapsulated fish oil in konjac gel increased the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content and decreased the n-6/n-3 PUFA ratio compared to the control group in Spanish salchichón. In addition, Domínguez, Pateiro, Munekata, and Campagnol (2016) also noticed that lipid modification of pâté by substitution of pork backfat with fish oil has been shown to be a good strategy to improve their nu- tritional quality, specifically to increase long chain n-3 fatty acids. Addi- tionally to lipid oxidation, many undesirable changes as redness loss, protein oxidation and development of volatile compounds perceived as off-flavours and/or rancidity were also reported in this type of meat products (Bernardi, Bertol, Pflanzer, Sgarbieri, & Pollonio, 2016). Strategies to prevent lipid oxidation of n-3 long-chain fatty acids in- volve the microencapsulation with coating material and the use of anti- oxidants (Rubio-Rodríguez et al., 2010). However, some authors reported significant increase in oxidative indexes due to addition of en- capsulated n-3 long-chain fatty acids (Keenan et al., 2015; Lorenzo et al., 2016; Pavlík et al., 2014). On the other hand, texture of meat products can be also affected by n-3 fatty acid enrichment demanding a pre-treat- ment to obtain a more stable product, such as reported for konjac matrix application, a feasible fat analogue, particularly in sausages (Triki, Herrero, Rodríguez-Salas, Jiménez-Colmenero, & Ruiz-Capillas, 2013). With this regards, Lorenzo et al. (2016) observed that the partial substi- tution of pork backfat by microencapsulated fish oil in konjac glucomannan matrix increased (P b 0.001) hardness, gumminess and chewiness, but did not influence springiness and cohesiveness in Span- ish salchichón. Among consumers, the consumption of natural antioxidants is pre- ferred compared to synthetic compounds (Pokorný, 2007). Natural an- tioxidants are widely distributed in nature and are also present in residues generated during food processing that present interesting op- tions to be exploited for reduction of the environmental impact of food processing and waste production (Schieber, Stintzing, & Carle, 2001). The phenolic composition of chestnut leaves includes many com- pounds as gallic and ellagic acid, rutin, quercetin, luteolin, epi- gallocatechin and kaempferol (Munekata, Franco, Trindade, & Lorenzo, 2016a). In addition, the evaluation of antioxidant potential by several methods as DPPH radical scavenge activity, reducing power and inhibi- tion of lipid peroxidation revealed that chestnut extract has the high po- tential to prevent oxidative reactions (Barreira, Ferreira, Oliveira, & Pereira, 2008). In beer processing, phenolic compounds are removed to render a clear beverage and prevent the formation of haze, which generates residues with high antioxidant potential. In this regard, many phenolic compounds were identified in beer residues as flavo- noids (catechin, epi-catechin and proanthocyanidins), some phenolic Meat Science 124 (2017) 54–60 ⁎ Corresponding author. E-mail address: jmlorenzo@ceteca.net (J.M. Lorenzo). 1 CNPq Scholarship holder. http://dx.doi.org/10.1016/j.meatsci.2016.11.002 0309-1740/© 2016 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Meat Science journal homepage: www.elsevier.com/locate/meatsci