Eur Food Res Technol (2009) 228:749–758 DOI 10.1007/s00217-008-0986-8 123 ORIGINAL PAPER Liver pâté from pigs fed conjugated linoleic acid and monounsaturated fatty acids Diana Martin · Teresa Antequera · Elena Muriel · Trinidad Perez-Palacios · Jorge Ruiz Received: 2 September 2008 / Revised: 6 November 2008 / Accepted: 17 November 2008 / Published online: 3 December 2008  Springer-Verlag 2008 Abstract Three levels (0, 1 and 2%) of an enriched con- jugated linoleic acid (CLA) oil (28% cis-9, trans-11 and 28% trans-10, cis-12 CLA) were combined with two levels of monounsaturated fatty acids (MUFAs) (low: 19% aver- age and high: 39% average) for pig feeding. Experimental liver pâtés were produced using the meat and liver of pigs. Chemical composition, thiobarbituric acid reactive sub- stances (TBARs) and fatty acid composition of the neutral lipids (NL), polar lipids (PL) and free fatty acids (FFAs) fractions of liver pâté at 0, 30 and 200 days of storage were studied. In general, the storage of liver pâté throughout the 200 days did not lead to relevant changes in the content of total saturated fatty acids (SFA), MUFA and polyunsatu- rated fatty acids (PUFA) of NL and PL as a consequence of the assayed dietary treatment. Total SFA, MUFA, PUFA, cis-9, trans-11 CLA and trans-10, cis-12 CLA contents from FFA signiWcantly decreased in pâtés from pigs fed 2% CLA at 200 days of storage, regardless the MUFA treat- ment. Both at the beginning and at the end of storage, the TBARs were higher for 0% CLA pâtés compared to 1 and 2% CLA pâtés. Both at day 0 and day 30 of storage, the TBARs’ values for 2% CLA pâtés were higher than those for 1% CLA pâtés. Therefore, dietary CLA at levels lower than 2% could show a protective eVect in pâté against lipid oxidation, but the susceptibility to lipid oxidation could be increased at higher levels of CLA supplementation. Keywords Conjugated linoleic acid · Monounsaturated fatty acids · Lipid oxidation · Pork · Pâté Introduction The conjugated linoleic acid (CLA) isomers have currently a great scientiWc interest, especially due to the beneWcial implications of dietary CLA in diVerent pathologies, such as anticarcinogenic eVect, reduce of body fat mass, decrease of serum cholesterol level or improvement of insulin sensitivity and immune function, demonstrated in experimental animals and human studies [1]. Feeding ani- mals with diets enriched in CLA have been proposed as an attractive approach for obtaining CLA-enriched foodstuVs, since the subsequent accumulation of CLA in animal tis- sues has been demonstrated [2, 3]. However, CLA supple- mentation also has an eVect on the fatty acid composition of animal tissues by increasing the saturated fatty acids (SFA) content and decreasing that of monounsaturated fatty acids (MUFAs) [2–4]. The resulting increase in the ratio of satu- rated to unsaturated fatty acids could have negative health implications [5]. Nevertheless, including high levels of MUFA on pig diets when using dietary CLA has been sug- gested as a strategy for counteracting the decrease in MUFA caused by CLA [3, 6]. Evidences about antioxidative eVects of CLA isomers have also been found. Several authors have reported lower values of thiobarbituric acid reactive substances (TBARs) in loins from CLA-fed pigs or in liver and mammary gland from CLA-fed rats [7, 8]. Ha et al. [9] D. Martin · T. Antequera · E. Muriel · T. Perez-Palacios · J. Ruiz (&) Tecnologia de Alimentos, Facultad de Veterinaria, Universidad de Extremadura, Avda. Universidad s/n, 10071 Caceres, Spain e-mail: jruiz@unex.es D. Martin e-mail: dimaga@unex.es