Eur Food Res Technol (2004) 218:584–588 DOI 10.1007/s00217-004-0909-2 ORIGINAL PAPER G. Brito · E. M. Peæa-MØndez · K. Novotnµ · C. Díaz · F. J. García Differentiation of heat-treated pork liver pastes according to their metal content using multivariate data analysis Received: 17 October 2003 / Revised: 12 February 2004 / Published online: 17 March 2004  Springer-Verlag 2004 Abstract The heavy metal composition of 80 samples of heat treated pork liver pastes from different brands canned in three different type of container was analysed. The metal concentration in the pastes together with multivar- iate techniques such as linear discriminant analysis, principal component analysis and factor analysis allow us to study the latent structure in the samples and follow the influence of the material of the container or/and the brand of origin. Keywords Heavy metals · Meat derivatives · Pastes · Chemometrics Introduction Pork liver pastes relate to a group of industrialized heat- treated meat products, which are obtained from chopped paste and are very popular with consumers in their countries of origin. Also, liver pastes contain ingredients such as fat, fecula, jelly, lactic proteins, spices, condi- ments, additives and salt. In the same way as pâtØ [1], all the ingredients are well ground to obtain a fine paste for easy spreading. In recent years, scientific research has been concen- trating more and more on characterizing foods. In par- ticular, meat has focused the attention of researchers, specialists in animal production, or policymakers. There have been several reasons for this concentration of re- sources to characterize foods: avoidance of fraudulent practices, among others, importance of packaging mate- rials, physico-chemical changes during packaging. The analytical control of metal content in food is of great importance. Minerals such as Fe, Zn, Cr, Mn and Cu are essential for human health. However, the evaluation of some of them, i.e., Cr, in food is not easy [2]. The World Health Organization (WHO) established maximum or minimum levels of these metals for an adequate dietary intake in adults [3]: Fe (10.0–50.0 mg), Zn (5.0–22.0 mg), Mn (2.0-20.0 mg), Cr (0.5–2.0 mg), Cu (1.2–3.0 mg). The liver is the main source of mineral elements in the products considered in this study. The natural content of certain metals contained in meat and meat products may be altered or modified by, among other numerous factors, primary and/or secondary contamination [4, 5]. Primary contamination results from the environmental pollution sources [6]. Secondary contamination may result from the contamination of muscle and fatty tissues by toxic heavy metals (Ni, Pb, Cd) and other elements during the pro- duction and further processing of meat and meat products [7, 8, 9]. If processes of metallic interchange between the pastes and the containers do not take place, then the main source of trace metals in pork liver pastes is the basic raw material (liver) and/or manufacture. Thus, some differ- ences in the metal content of samples of different origin could be inferred. In a previous paper, Brito et al. [9] have determined the heavy metal content in pork liver pastes canned in ferrous material with soldering and non-ferrous materials without soldering. It was found that metal such as Cu, Mn, Zn and Ni are present at relatively low levels in all samples analysed, in the ranges Cu 0.5–2.4 mgg 1 , Mn non-detected–5.8 mgg 1 , Zn 0.7–4.2 mgg 1 , Ni non- detected–4.15 mgg 1 , while Fe levels are in the range 4.33–296.26 mgg 1 . The rapid advances in computer technology, together with the development of multivariate statistical tools in data analysis, allow the use of chemometrics as a G. Brito · E. M. Peæa-MØndez ( ) ) · C. Díaz · F. J. García Department of Analytical Chemistry, Nutrition and Food Chemistry, Faculty of Chemistry, University of La Laguna, Campus de Anchieta, 38071 La Laguna, Tenerife, Spain e-mail: empena@ull.es K. Novotnµ Department of Analytical Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno, Czech Republic Present address: G. Brito, Department of Health, Canary Islands Public Health Service, Canary Government, 38004-S/C de Tenerife, Tenerife, Spain