Food Additives and Contaminants: Part B Vol. 4, No. 3, September 2011, 180–184
Cadmium concentrations in the liver of 10 different pig genetic lines from Vojvodina, Serbia V.M. Tomovic´a*, Lj.S. Petrovic´a, M.S. Tomovic´b, Zˇ.S. Kevresˇ anc, M.R. Jokanovic´a, N.R. Dzˇinic´a and A.R. Despotovic´d a
Faculty of Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia; bTechnical School ‘‘Pavle Savic´’’, Sˇajkasˇka 34, 21000 Novi Sad, Serbia; cInstitute for Food Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia; dBiotechnical Faculty Podgorica, University of Montenegro, Mihaila Lalic´a 1, 81000 Podgorica, Montenegro (Received 6 January 2011; final version received 14 May 2011) Cadmium concentrations were determined in 480 liver samples from 10 different pig genetic lines produced in Vojvodina (Serbia). Cadmium levels were determined by flame atomic absorption spectrometry after mineralization by dry ashing. The difference in cadmium levels in analysed liver tissues was not significant ( p40.05) between the various genetic lines. However, large variations in cadmium levels (from 0.03 to 0.27 mg/kg) in liver tissues indicated its availability in the local agricultural environment in Vojvodina. The average level of cadmium (0.13 mg/kg) was higher than the levels reported in pork liver from some developed countries. Keywords: meat; heavy metals, cadmium
Introduction People may be exposed to potentially harmful chemical, physical and biological agents in air, food, water or soil (Robards and Worsfold 1991; Ja¨rup 2003). The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic. These metals have been extensively studied and their effects on human health regularly reviewed by international bodies such as the World Health Organisation (WHO) (Ja¨rup 2003). The World Health Organisation (WHO 1992) has recommended that the provisional tolerable weekly intake (PTWI) of cadmium should not exceed 0.4–0.5 mg per person or 0.007 mg/kg body weight. Food is the most important source of cadmium exposure in the general non-smoking population in most countries (Doyle and Spaulding 1978; Robards and Worsfold 1991; Ja¨rup 2003; Ja¨rup and A˚kesson 2009; Andre´e et al. 2010). Cadmium also accumulates in the food chain (Sharma et al. 1982; Linde´n et al. 2003; Oskarsson et al. 2004; Dave Oomah et al. 2007). In mammals, cadmium is virtually absent at birth but accumulates with time, especially in the liver and kidney (Henke et al. 1970; Robards and Worsfold 1991; Linde´n et al. 1999; Sapunar-Postruzˇnik et al. 2001; Ja¨rup and A˚kesson 2009; Andre´e et al. 2010). Cadmium is efficiently retained in liver and kidney with a very long biological half-life ranging from 10 to
*Corresponding author. Email: [email protected] ISSN 1939–3210 print/ISSN 1939–3229 online ß 2011 Taylor & Francis http://dx.doi.org/10.1080/19393210.2011.589035 http://www.tandfonline.com
30 years (Friberg et al. 1974; Ja¨rup and A˚kesson 2009; Andre´e et al. 2010). Reported concentrations of cadmium in foods, i.e. pork meat and offal, vary widely (Vos et al. 1986; Jorhem et al. 1991; Niemi et al. 1991; Falandysz 1993; Tahvonen and Kumpulainen 1994; Doganoc 1996; Grawe´ et al. 1997; Linde´n et al. 1999, 2001, 2003; Sapunar-Postruzˇnik et al. 2001; Ulrich et al. 2001; Lo´pez-Alonso et al. 2007). Also, the literature indicates a great variability in the daily intake of this element (Galal-Gorchev 1993; Egan et al. 2002; Larsen et al. 2002; Marzec and Schlegel-Zawadzka 2004; Lee et al. 2006; Vromman et al. 2010) in different countries. Maximum cadmium levels in food have been regulated in Republic of Serbia by national legislation (Serbian Regulation 1992a, 1992b, 2002), which is in accordance with European Union legislation (Commission Regulation (EC) No 1881/2006). The maximum levels are 0.05, 0.5 and 1.0 mg/kg (wet weight) for pig meat, liver and kidney, respectively. Pork is the most widely consumed meat in the EU, and consumption has been steadily increasing (Williamson et al. 2005). On the basis of the available data from the Statistical Office of the Republic of Serbia (2009), the total consumption of meat in Serbia is 43.3 kg/person/year, including the consumption of pork at 16 kg/person/year. The Autonomous Province of Vojvodina (the northern part of the
Food Additives and Contaminants: Part B Republic of Serbia) is a region where the number of animals of the porcine species and the production of pork are of high economic importance. Over 30% of the total number of pigs slaughtered annually in Serbia comes from Vojvodina. The benefits of cross-breeding programmes in pigs have been demonstrated (Smith and King 1964; Schneider et al. 1982; Buchanan 1987; Visscher et al. 2000). The main objectives, economically, of the pig (cross)breeding programme in Vojvodina were primarily litter size, feed conversion and daily weight gain, carcass conformation, lean meat percentage and the technological quality of the meat (pH value, water holding capacity and colour), i.e. absence of PSE (pale, soft, and exudative). The overall objective is to produce high quality pork at the lowest possible cost, to ensure the competitiveness of Vojvodian pork on the international meat market. Thus, the aims of this study were: (i) to establish cadmium levels in liver of pigs from Vojvodina; (ii) to ascertain possible differences in cadmium levels in liver from 10 different pig genetic lines (two pure and eight crossbred pigs), reared under the same, current conditions used in Vojvodina for pork production; (iii) to compare the obtained values with the maximum level set by European Commission, i.e. by national legislation.
Materials and methods Animals, sampling and preparing The pigs used in the present study were produced in a pig (cross)-breeding programme provided by nucleus and multiplication farms in Vojvodina (GGP-GP traditional pyramid structure of genetic programme) (Visscher et al. 2000; Tomovic´ et al. 2011). In this breeding programme five purebred pigs were used. Large White (LW) and Landrace (L) were used as female lines; Duroc (D), Hampshire (H) and Pietrain (P) were used as male lines. The investigation comprised 480 pigs (castrated males and females) from 10 different genetic lines (two purebred and eight crossbred pigs): [LW, n ¼ 48; L, n ¼ 48; LW L, n ¼ 48; L LW, n ¼ 48; D (LW L), n ¼ 48; D (L LW), n ¼ 48; (D P) (LW L), n ¼ 48; (D P) (L LW), n ¼ 48; (H P) (LW L), n ¼ 48; (H P) (L LW), n ¼ 48]. The pigs were fattened at the 10 largest production farms in the northern part of the Republic of Serbia (Autonomous Province of Vojvodina). The pig fattening involved the following phases: starting period (from 15 to 25 kg), growing period (from 25 to 60 kg) and finishing period (from 60 to 110 kg). The diets were based on locally produced corn and soybean meals, and were formulated to meet nutritional requirements (National Research Council 1998) for the different growth phases. The finishers were housed in pens with
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fully slatted floor and 0.80 m2 space allocation per pig. Each pen contained 10 animals. The environmental temperature in the building was 22 C. All pigs had ad libitum access to diet and water. Animals were randomly selected over a 1-year period. Four pigs from each genetic line were taken every month from the same farm. The pigs were slaughtered at a live weight of between 95 and 110 kg and at about 6 months old in the two largest Vojvodian slaughterhouses according to routine procedure. Liver were conventionally chilled for 24 h in a chiller at 2–4 C. The samples for chemical analysis (approximately 250 g) taken after homogenization of the whole liver, vacuum packaged in polyethylene bags and stored at 40 C until analysis.
Analytical methods and quality control Cadmium (Cd) contents of the liver were determined after dry-ash mineralization according to the following procedure (Gorsuch 1970; Hermida et al. 2006; Tomovic´ et al. 2011): a 10-g sample was weighed into a porcelain crucible and dried in a laboratory oven at 105 C for 3 h. After drying, the sample was charred on a hot plate and then incinerated in a muffle furnace at 450 C overnight (16 h). If necessary, the ash was bleached with nitric acid/deionized water (1 : 2, v/v), evaporated to dryness and heated in a muffle furnace for 1 h. When a suitable ash was obtained, it was moistened with little water, treated with 10 ml of hydrochloric acid/deionized water (1 : 1, v/v) and evaporated to dryness. Finally, the ash was redissolved with 10 ml of hydrochloric acid/deionized water (1 : 9, v/v), transferred into a 25-ml volumetric flask and diluted to volume with deionized water. Cd was measured in the ash solution by flame atomic absorption spectroscopy according to the manufacturer’s instructions (Varian Spectra AA 10; Varian Techtron Pty Limited, Mulgrave, Victoria, Australia 1989). Measurement was made under the optimized parameters mentioned in Table 1. A strict analytical quality control programme was employed during the study. Quality control of analytical measurements was performed using standard reference material (ERM-CE278, mussel tissue; IRMM, Geel, Belgium) and the results are presented in Table 2. In every series of samples, two blanks and two standard reference material samples were included (Tomovic´ et al. 2011). All chemicals used in sample treatments were high purity grade (Suprapur; Merck GmbH, Darmstadt, Germany) and deionized Milli-Q water was used throughout. The porcelain crucible and glassware were cleaned prior to use by soaking overnight in 10% v/v HNO3 and rinsed with deionized Milli-Q water. Standard stock solutions of analyzed metals were
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V.M. Tomovic´ et al. Table 1. Parameters for AAS measurement.
Element Cd
Wavelength (nm)
Band width (nm)
228.8
0.5
Table 2. Results of analytical quality control programme (n ¼ 8) for the determination of cadmium in pig liver.
Flame Air/acetylene (oxidizing)
0.348 0.007 98.3 6.22 3.68 0.050 0.075
0.02
Table 3. Cadmium levels in the liver of various genetic lines of pigs from Vojvodina.
Cd Certified concentration (mg/kg) Recovery (%) Method repeatability/precision as RSD (%) Limit of detection (mg/kg) Limit of quantitation (mg/kg)
Sensitivity (mg/ml)
Genetic line
Cd concentration (mg/kg wet weight) Parameters
LW (n ¼ 48) Average SD Range
0.14 0.06 0.05 0.27
Average SD Range
0.12 0.07 0.03 0.27
Average SD Range
0.13 0.05 0.03 0.26
Average SD Range
0.13 0.04 0.07 0.22
Average SD Range
0.15 0.07 0.04 0.27
Average SD Range
0.13 0.05 0.04 0.24
Average SD Range
0.12 0.06 0.03 0.25
Average SD Range
0.13 0.06 0.03 0.26
Average SD Range
0.15 0.06 0.03 0.26
Average SD Range
0.13 0.06 0.04 0.27 0.96 0.47
Average SD Range
0.13 0.06 0.03–0.27
L (n ¼ 48)
prepared immediately before use by dilution (with deionized water) of a 1000 mg/l standard solution. All analyses were performed in duplicate.
Statistical analysis All data are presented as average, standard deviation (SD) and range. Analysis of variance (one-way ANOVA) was used to test differences between average values, employing the software package STATISTICA 8.0 (StatSoft, Inc. 2008).
Results and discussion Average concentrations, standard deviations and range of cadmium in the liver tissues samples from 10 different pig genetic lines are presented in Table 3. Only 5.6% of liver sample were below the detection limit. The minimum Cd content found in liver samples was greater than half the detection limit; therefore, all measured values were used for calculating the mean (Miranda et al. 2001). In increasing order, the genetic lines according to average cadmium content in liver samples was (in mg/kg): L5(D P) (LW L)5D (L LW)5 (H P) (L LW)5L LW, LW L5(D P) (L LW)5LW5D (LW L)5(H P) (LW L). Cadmium levels found in the present study did not differ significantly (F ¼ 0.96; p ¼ 0.47) among liver tissue for the different genetic lines. Individual cadmium concentrations (maximum/ minimum quotient) in liver tissues differed between animals belonging to the same genetic line, from the same farm, raised under the same conditions, given the same feed and slaughtered at the same age (variation
LW L (n ¼ 48)
L LW (n ¼ 48)
D (LW L) (n ¼ 48)
D (L LW) (n ¼ 48)
(D P) (LW L) (n ¼ 48)
(D P) (L LW) (n ¼ 48)
(H P) (LW L) (n ¼ 48)
(H P) (L LW) (n ¼ 48) F value p value All animals (n ¼ 480)
within the farm), from 3.0 (genetic line: L LW) to 9.6 [genetic line: (D P) (L LW)], with an average of 7.2. The inter-farm variation for cadmium levels in liver was higher (maximum/minimum quotient ¼ 10.1) than within-farm. Average wet weight level for cadmium in liver from pigs in Vojvodina was 0.13 mg/kg. The maximum cadmium concentration found (0.27 mg/kg) in the
Food Additives and Contaminants: Part B present study was below maximum level (0.5 mg/kg) set by EU and Serbian legislation (Commission Regulation (EC) No 1881/2006; Serbian Regulations 1992a, 1992b, 2002). Overall, 92.9% of liver samples had cadmium levels below half of the maximum level. The average concentration of cadmium in pig liver from Vojvodina was higher than values reported for Spain (Lo´pez-Alonso et al. 2007), Denmark (Larsen et al. 2002), Sweden (Jorhem et al. 1991; Linde´n et al. 2001), Czech Republic (Ulrich et al. 2001), Slovenia (Doganoc 1996), Finland (Niemi et al. 1991; Tahvonen and Kumpulainen 1994), Poland (Falandysz 1993), or The Netherland (Vos et al. 1986). On the other hand, cadmium levels in pig liver from Croatia (SapunarPostruzˇnik et al. 2001), a neighbor country of Serbia, far exceeded the levels found in this study, i.e. several times higher than maximum set level. According to many reports (Sharma et al. 1982; Linde´n et al. 1999, 2001, 2003; Grawe´ et al. 1997; Sapunar-Postruzˇnik et al. 2001; Oskarsson et al. 2004; Andre´e et al. 2010) cadmium concentrations in animal tissues, especially liver and kidney, are strongly related to the cadmium levels in feedstuffs. In conclusion, the results of the present study show that the levels of cadmium in the liver of pigs, reared under the same conditions, were not influenced by genetic lines. However, the variations in cadmium levels in analysed liver tissues indicate cadmium availability in the local agricultural environment in Vojvodina.
Acknowledgements This research was financially supported by the Ministry of Science and Technological Development, Republic of Serbia, project TR31032. These results are part of project No 114451-2091/2011 (Improvement of meat quality from indigenous and modern pig breeds produced in Vojvodina for the production of traditional dry fermented sausages and dry cured meat products), which is financially supported by the Provincial Secretariat for Science and Technological Development, Autonomous Province of Vojvodina, Republic of Serbia.
References Andre´e S, Jira W, Schwind K-H, Wagner H, Schwa¨gele F. 2010. Chemical safety of meat and meat products. Meat Sci. 86:38–48. Buchanan DS. 1987. The crossbred sire: experimental results for swine. J Anim Sci. 65:117–127. Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Off J Eur Commun. L364:5–24. Dave Oomah B, Berekoff B, Li-Chan ECY, Mazza G, Kenaschuk EO, Duguid SD. 2007. Cadmium-binding protein components of flaxseed: Influence of cultivar and location. Food Chem. 100:318–325.
183
Doganoc DZ. 1996. Lead and cadmium concentrations in meat, liver and kidneys of Slovenian cattle and pigs from 1989-1993. Food Addit Contam. 13:237–241. Doyle JJ, Spaulding JE. 1978. Toxic and essential trace elements in meat – a review. J Anim Sci. 47:398–406. Egan SK, Tao SS-H, Pennington JAT, Bolger PM. 2002. US Food and Drug Administration’s Total Diet Study: intake of nutritional and toxic elements, 1991–96. Food Addit Contam. 19:103–125. Falandysz J. 1993. Some toxic and essential trace metals in swine from Northern Poland. Sci Total Environ. 136:193–204. Friberg L, Piscator M, Nordberg GF, Kjellstrom T. 1974. Cadmium in the environment. 2nd ed. Cleveland (OH): CRC Press. Galal-Gorchev H. 1993. Dietery intake, levels in food and estimated intake of lead, cadmium, and mercury. Food Addit Contam. 10:115–128. Gorsuch TT. 1970. The destruction of organic matter. 1st ed. Oxford: Pergamon Press. Grawe´ KP, Thierfelder T, Jorhem L, Oskarsson A. 1997. Cadmium levels in kidneys from Swedish pigs in relation to environmental factors – temporal and spatial trends. Sci Total Environ. 208:111–122. Henke G, Sachs H, Bohn G. 1970. Cadmium determination by neutron activation analysis of liver and kidneys from children and young people. Arch Toxicol. 26:8–16 (in German). Hermida M, Gonzalez M, Miranda M, Rodrı´ guez-Otero JL. 2006. Mineral analysis in rabbit meat from Galicia (NW Spain). Meat Sci. 73:635–639. Ja¨rup L. 2003. Hazards of heavy metal contamination. British Medical Bulletin. 68:167–182. Ja¨rup L, A˚kesson A. 2009. Current status of cadmium as an environmental health problem. Toxicol Appl Pharmacol. 238:201–208. Jorhem L, Slorach S, Sundstro¨m B, Ohlin B. 1991. Lead, cadmium, arsenic and mercury in meat, liver and kidney of Swedish pigs and cattle in 1984–88. Food Addit Contam. 8:201–211. Larsen EH, Andersen NL, Møller A, Petersen A, Mortensen GK, Petersen J. 2002. Monitoring the content and intake of trace elements from food in Denmark. Food Addit Contam. 19:33–46. Lee H-S, Cho Y-H, Park S-O, Kye S-H, Kim B-H, Hahm T-S, Kim M, Lee JO, Kim C-I. 2006. Dietary exposure of the Korean population to arsenic, cadmium, lead and mercury. J Food Compos Anal. 19:S31–S37. Linde´n A, Olsson I-M, Bensryd I, Lundh T, Skerfving S, Oskarsson A. 2003. Monitoring of cadmium in the chain from soil via crops and feed to pig blood and kidney. Ecotoxicol Environ Saf. 55:213–222. Linde´n A, Andersson K, Oskarsson A. 2001. Cadmium in organic and conventional pig production. Arch Environ Contam Toxicol. 40:425–431. Linde´n A, Olsson I-M, Oskarsson A. 1999. Cadmium levels in feed components and kidneys of growing/finishing pigs. J AOAC Int. 82:1288–1297. Lo´pez-Alonso M, Miranda M, Castillo C, Herna´ndez J, Garcı´ a-Vaquero M, Benedito JL. 2007. Toxic and essential metals in liver, kidney and muscle of pigs at slaughter
184
V.M. Tomovic´ et al.
in Galicia, north-west Spain. Food Addit Contam. 24:943–954. Marzec Z, Schlegel-Zawadzka M. 2004. Exposure to cadmium, lead and mercury in the adult population from Eastern Poland, 1990-2002. Food Addit Contam. 21:963–970. Miranda M, Lo´pez Alonso M, Castillo C, Herna´ndez J, Benedito JL. 2001. Cadmium levels in liver, kidney and meat in calves from Asturias (North Spain). Eur Food Res Technol. 212:426–430. National Research Council. 1998. Nutrient requirements of swine. 10th ed. Washington (DC): National Academy Press. Niemi A, Vena¨la¨inen ER, Hirvi T, Hirn J, Karppanen E. 1991. The lead, cadmium and mercury concentrations in muscle, liver and kidney from Finnish pigs and kidney from pigs in Finland during 1987–1988. Z LebensmUntersuchung Forschung A. 192:427–429. Oskarsson A, Widell A, Olsson I-M, Grawe KP. 2004. Cadmium in food chain and health effects in sensitive population groups. BioMetals. 17:531–534. Robards K, Worsfold P. 1991. Cadmium: Toxicology and analysis: A review. Analyst. 116:549–568. Sapunar-Postruzˇnik J, Bazˇulic´ D, Grubelic´ M, Kubala Drincˇic´ H, Njari B. 2001. Cadmium in animal feed and in foodstuffs of animal origin. Food Technol Biotechnol. 39:67–71. Serbian Regulation 1992a. Pravilnik o kolicˇinama pesticida, metala i metaloida i drugih otrovnih supstancija, hemioterapeutiku, anabolika i drugih supstancija koje se mogu nalaziti u namirnicama [Content of Pesticides, Metals, Metalloids and other toxic substances in foods]. Sluzˇbeni list SRJ, broj 5 [Official Gazette, No 5,]. Serbian Regulation 1992b. Pravilnik o kolicˇinama pesticida, metala i metaloida i drugih otrovnih supstancija, hemioterapeutiku, anabolika i drugih supstancija koje se mogu nalaziti u namirnicama [Content of Pesticides, Metals, Metalloids and other toxic substances in foods]. Sluzˇbeni list SRJ, broj 11 [Official Gazette, No 11]. Serbian Regulation 2002. Pravilnik o kolicˇinama pesticida, metala i metaloida i drugih otrovnih supstancija, hemioterapeutiku, anabolika i drugih supstancija koje se mogu nalaziti u namirnicama [Content of Pesticides, Metals,
Metalloids and other toxic substances in foods]. Sluzˇbeni list SRJ, broj 32 [Official Gazette, No 32]. Schneider JF, Christian LL, Kuhlers DL. 1982. Crossbreeding in swine: genetic effects on litter performance. J Anim Sci. 51:739–746. Sharma RP, Street JC, Shure JL. 1982. Translocation of lead and cadmium from feed to edible tissues of swine. J Food Saf. 4:151–163. Smith C, King JWB. 1964. Crossbreeding and litter production in British pigs. Anim Prod. 6:265–271. StatSoft, Inc. 2008. STATISTICA (data analysis software system), version 8.0. [cited 2010 June 23]. Available from: http://www.statsoft.com/. Tahvonen R, Kumpulainen J. 1994. Lead and cadmium contents in pork, beef and chicken, and in pig and cow liver in Finland during 1991. Food Addit Contam. 11:415–426. Tomovic´ VM, Petrovic´ LjS, Tomovic´ MS, Kevresˇ an ZˇS, Dzˇinic´ NR. 2011. Determination of mineral contents of semimembranosus muscle and liver from pure and crossbred pigs in Vojvodina (northern Serbia). Food Chem. 124:342–348. Ulrich R, Raszyk J, Napravnik A. 2001. Variations in contamination by mercury, cadmium and lead on swine farms in the district of Hodonin in 1994 to 1999. Vet Med (Czech). 46:132–139. Varian. 1989. Flame atomic absorption spectrometry. Analytical methods. Mulgrave Victoria, Australia: Varian Techtron Pty Ltd. Visscher PM, Pong-Wong R, Whittemore CT, Haley CS. 2000. Impact of biotechnology on pig (cross)breeding programmes. Livest Prod Sci. 65:57–70. Vos G, Teeuwen JJMH, van Delft W. 1986. Arsenic, cadmium, lead and mercury in meat, livers, and kidneys of swine slaughtered in The Netherlands during the period 1980–1985. Z Lebensm-Untersuchung Forschung A. 183:397–401. Vromman V, Waegeneers N, Cornelis C, De Boosere I, Van Holderbeke M, Vinkx C, Smolders E, Huyghebaert A, Pussemier L. 2010. Dietary cadmium intake by the Belgian adult population. Food Addit Contam. 27:1665–1673. WHO. 1992. Cadmium. Environmental Health Criteria 134. Geneva: World Health Organisation. Williamson CS, Foster RK, Stanner SA, Buttriss JL. 2005. Red meat in the diet. Nutr Bull. 30:323–355.
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Cadmium concentrations in the liver of 10 different pig genetic lines from Vojvodina, Serbia V.M. Tomovic´a*, Lj.S. Petrovic´a, M.S. Tomovic´b, Zˇ.S. Kevresˇ anc, M.R. Jokanovic´a, N.R. Dzˇinic´a and A.R. Despotovic´d a
Faculty of Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia; bTechnical School ‘‘Pavle Savic´’’, Sˇajkasˇka 34, 21000 Novi Sad, Serbia; cInstitute for Food Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia; dBiotechnical Faculty Podgorica, University of Montenegro, Mihaila Lalic´a 1, 81000 Podgorica, Montenegro (Received 6 January 2011; final version received 14 May 2011) Cadmium concentrations were determined in 480 liver samples from 10 different pig genetic lines produced in Vojvodina (Serbia). Cadmium levels were determined by flame atomic absorption spectrometry after mineralization by dry ashing. The difference in cadmium levels in analysed liver tissues was not significant ( p40.05) between the various genetic lines. However, large variations in cadmium levels (from 0.03 to 0.27 mg/kg) in liver tissues indicated its availability in the local agricultural environment in Vojvodina. The average level of cadmium (0.13 mg/kg) was higher than the levels reported in pork liver from some developed countries. Keywords: meat; heavy metals, cadmium
Introduction People may be exposed to potentially harmful chemical, physical and biological agents in air, food, water or soil (Robards and Worsfold 1991; Ja¨rup 2003). The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic. These metals have been extensively studied and their effects on human health regularly reviewed by international bodies such as the World Health Organisation (WHO) (Ja¨rup 2003). The World Health Organisation (WHO 1992) has recommended that the provisional tolerable weekly intake (PTWI) of cadmium should not exceed 0.4–0.5 mg per person or 0.007 mg/kg body weight. Food is the most important source of cadmium exposure in the general non-smoking population in most countries (Doyle and Spaulding 1978; Robards and Worsfold 1991; Ja¨rup 2003; Ja¨rup and A˚kesson 2009; Andre´e et al. 2010). Cadmium also accumulates in the food chain (Sharma et al. 1982; Linde´n et al. 2003; Oskarsson et al. 2004; Dave Oomah et al. 2007). In mammals, cadmium is virtually absent at birth but accumulates with time, especially in the liver and kidney (Henke et al. 1970; Robards and Worsfold 1991; Linde´n et al. 1999; Sapunar-Postruzˇnik et al. 2001; Ja¨rup and A˚kesson 2009; Andre´e et al. 2010). Cadmium is efficiently retained in liver and kidney with a very long biological half-life ranging from 10 to
*Corresponding author. Email: [email protected] ISSN 1939–3210 print/ISSN 1939–3229 online ß 2011 Taylor & Francis http://dx.doi.org/10.1080/19393210.2011.589035 http://www.tandfonline.com
30 years (Friberg et al. 1974; Ja¨rup and A˚kesson 2009; Andre´e et al. 2010). Reported concentrations of cadmium in foods, i.e. pork meat and offal, vary widely (Vos et al. 1986; Jorhem et al. 1991; Niemi et al. 1991; Falandysz 1993; Tahvonen and Kumpulainen 1994; Doganoc 1996; Grawe´ et al. 1997; Linde´n et al. 1999, 2001, 2003; Sapunar-Postruzˇnik et al. 2001; Ulrich et al. 2001; Lo´pez-Alonso et al. 2007). Also, the literature indicates a great variability in the daily intake of this element (Galal-Gorchev 1993; Egan et al. 2002; Larsen et al. 2002; Marzec and Schlegel-Zawadzka 2004; Lee et al. 2006; Vromman et al. 2010) in different countries. Maximum cadmium levels in food have been regulated in Republic of Serbia by national legislation (Serbian Regulation 1992a, 1992b, 2002), which is in accordance with European Union legislation (Commission Regulation (EC) No 1881/2006). The maximum levels are 0.05, 0.5 and 1.0 mg/kg (wet weight) for pig meat, liver and kidney, respectively. Pork is the most widely consumed meat in the EU, and consumption has been steadily increasing (Williamson et al. 2005). On the basis of the available data from the Statistical Office of the Republic of Serbia (2009), the total consumption of meat in Serbia is 43.3 kg/person/year, including the consumption of pork at 16 kg/person/year. The Autonomous Province of Vojvodina (the northern part of the
Food Additives and Contaminants: Part B Republic of Serbia) is a region where the number of animals of the porcine species and the production of pork are of high economic importance. Over 30% of the total number of pigs slaughtered annually in Serbia comes from Vojvodina. The benefits of cross-breeding programmes in pigs have been demonstrated (Smith and King 1964; Schneider et al. 1982; Buchanan 1987; Visscher et al. 2000). The main objectives, economically, of the pig (cross)breeding programme in Vojvodina were primarily litter size, feed conversion and daily weight gain, carcass conformation, lean meat percentage and the technological quality of the meat (pH value, water holding capacity and colour), i.e. absence of PSE (pale, soft, and exudative). The overall objective is to produce high quality pork at the lowest possible cost, to ensure the competitiveness of Vojvodian pork on the international meat market. Thus, the aims of this study were: (i) to establish cadmium levels in liver of pigs from Vojvodina; (ii) to ascertain possible differences in cadmium levels in liver from 10 different pig genetic lines (two pure and eight crossbred pigs), reared under the same, current conditions used in Vojvodina for pork production; (iii) to compare the obtained values with the maximum level set by European Commission, i.e. by national legislation.
Materials and methods Animals, sampling and preparing The pigs used in the present study were produced in a pig (cross)-breeding programme provided by nucleus and multiplication farms in Vojvodina (GGP-GP traditional pyramid structure of genetic programme) (Visscher et al. 2000; Tomovic´ et al. 2011). In this breeding programme five purebred pigs were used. Large White (LW) and Landrace (L) were used as female lines; Duroc (D), Hampshire (H) and Pietrain (P) were used as male lines. The investigation comprised 480 pigs (castrated males and females) from 10 different genetic lines (two purebred and eight crossbred pigs): [LW, n ¼ 48; L, n ¼ 48; LW L, n ¼ 48; L LW, n ¼ 48; D (LW L), n ¼ 48; D (L LW), n ¼ 48; (D P) (LW L), n ¼ 48; (D P) (L LW), n ¼ 48; (H P) (LW L), n ¼ 48; (H P) (L LW), n ¼ 48]. The pigs were fattened at the 10 largest production farms in the northern part of the Republic of Serbia (Autonomous Province of Vojvodina). The pig fattening involved the following phases: starting period (from 15 to 25 kg), growing period (from 25 to 60 kg) and finishing period (from 60 to 110 kg). The diets were based on locally produced corn and soybean meals, and were formulated to meet nutritional requirements (National Research Council 1998) for the different growth phases. The finishers were housed in pens with
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fully slatted floor and 0.80 m2 space allocation per pig. Each pen contained 10 animals. The environmental temperature in the building was 22 C. All pigs had ad libitum access to diet and water. Animals were randomly selected over a 1-year period. Four pigs from each genetic line were taken every month from the same farm. The pigs were slaughtered at a live weight of between 95 and 110 kg and at about 6 months old in the two largest Vojvodian slaughterhouses according to routine procedure. Liver were conventionally chilled for 24 h in a chiller at 2–4 C. The samples for chemical analysis (approximately 250 g) taken after homogenization of the whole liver, vacuum packaged in polyethylene bags and stored at 40 C until analysis.
Analytical methods and quality control Cadmium (Cd) contents of the liver were determined after dry-ash mineralization according to the following procedure (Gorsuch 1970; Hermida et al. 2006; Tomovic´ et al. 2011): a 10-g sample was weighed into a porcelain crucible and dried in a laboratory oven at 105 C for 3 h. After drying, the sample was charred on a hot plate and then incinerated in a muffle furnace at 450 C overnight (16 h). If necessary, the ash was bleached with nitric acid/deionized water (1 : 2, v/v), evaporated to dryness and heated in a muffle furnace for 1 h. When a suitable ash was obtained, it was moistened with little water, treated with 10 ml of hydrochloric acid/deionized water (1 : 1, v/v) and evaporated to dryness. Finally, the ash was redissolved with 10 ml of hydrochloric acid/deionized water (1 : 9, v/v), transferred into a 25-ml volumetric flask and diluted to volume with deionized water. Cd was measured in the ash solution by flame atomic absorption spectroscopy according to the manufacturer’s instructions (Varian Spectra AA 10; Varian Techtron Pty Limited, Mulgrave, Victoria, Australia 1989). Measurement was made under the optimized parameters mentioned in Table 1. A strict analytical quality control programme was employed during the study. Quality control of analytical measurements was performed using standard reference material (ERM-CE278, mussel tissue; IRMM, Geel, Belgium) and the results are presented in Table 2. In every series of samples, two blanks and two standard reference material samples were included (Tomovic´ et al. 2011). All chemicals used in sample treatments were high purity grade (Suprapur; Merck GmbH, Darmstadt, Germany) and deionized Milli-Q water was used throughout. The porcelain crucible and glassware were cleaned prior to use by soaking overnight in 10% v/v HNO3 and rinsed with deionized Milli-Q water. Standard stock solutions of analyzed metals were
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V.M. Tomovic´ et al. Table 1. Parameters for AAS measurement.
Element Cd
Wavelength (nm)
Band width (nm)
228.8
0.5
Table 2. Results of analytical quality control programme (n ¼ 8) for the determination of cadmium in pig liver.
Flame Air/acetylene (oxidizing)
0.348 0.007 98.3 6.22 3.68 0.050 0.075
0.02
Table 3. Cadmium levels in the liver of various genetic lines of pigs from Vojvodina.
Cd Certified concentration (mg/kg) Recovery (%) Method repeatability/precision as RSD (%) Limit of detection (mg/kg) Limit of quantitation (mg/kg)
Sensitivity (mg/ml)
Genetic line
Cd concentration (mg/kg wet weight) Parameters
LW (n ¼ 48) Average SD Range
0.14 0.06 0.05 0.27
Average SD Range
0.12 0.07 0.03 0.27
Average SD Range
0.13 0.05 0.03 0.26
Average SD Range
0.13 0.04 0.07 0.22
Average SD Range
0.15 0.07 0.04 0.27
Average SD Range
0.13 0.05 0.04 0.24
Average SD Range
0.12 0.06 0.03 0.25
Average SD Range
0.13 0.06 0.03 0.26
Average SD Range
0.15 0.06 0.03 0.26
Average SD Range
0.13 0.06 0.04 0.27 0.96 0.47
Average SD Range
0.13 0.06 0.03–0.27
L (n ¼ 48)
prepared immediately before use by dilution (with deionized water) of a 1000 mg/l standard solution. All analyses were performed in duplicate.
Statistical analysis All data are presented as average, standard deviation (SD) and range. Analysis of variance (one-way ANOVA) was used to test differences between average values, employing the software package STATISTICA 8.0 (StatSoft, Inc. 2008).
Results and discussion Average concentrations, standard deviations and range of cadmium in the liver tissues samples from 10 different pig genetic lines are presented in Table 3. Only 5.6% of liver sample were below the detection limit. The minimum Cd content found in liver samples was greater than half the detection limit; therefore, all measured values were used for calculating the mean (Miranda et al. 2001). In increasing order, the genetic lines according to average cadmium content in liver samples was (in mg/kg): L5(D P) (LW L)5D (L LW)5 (H P) (L LW)5L LW, LW L5(D P) (L LW)5LW5D (LW L)5(H P) (LW L). Cadmium levels found in the present study did not differ significantly (F ¼ 0.96; p ¼ 0.47) among liver tissue for the different genetic lines. Individual cadmium concentrations (maximum/ minimum quotient) in liver tissues differed between animals belonging to the same genetic line, from the same farm, raised under the same conditions, given the same feed and slaughtered at the same age (variation
LW L (n ¼ 48)
L LW (n ¼ 48)
D (LW L) (n ¼ 48)
D (L LW) (n ¼ 48)
(D P) (LW L) (n ¼ 48)
(D P) (L LW) (n ¼ 48)
(H P) (LW L) (n ¼ 48)
(H P) (L LW) (n ¼ 48) F value p value All animals (n ¼ 480)
within the farm), from 3.0 (genetic line: L LW) to 9.6 [genetic line: (D P) (L LW)], with an average of 7.2. The inter-farm variation for cadmium levels in liver was higher (maximum/minimum quotient ¼ 10.1) than within-farm. Average wet weight level for cadmium in liver from pigs in Vojvodina was 0.13 mg/kg. The maximum cadmium concentration found (0.27 mg/kg) in the
Food Additives and Contaminants: Part B present study was below maximum level (0.5 mg/kg) set by EU and Serbian legislation (Commission Regulation (EC) No 1881/2006; Serbian Regulations 1992a, 1992b, 2002). Overall, 92.9% of liver samples had cadmium levels below half of the maximum level. The average concentration of cadmium in pig liver from Vojvodina was higher than values reported for Spain (Lo´pez-Alonso et al. 2007), Denmark (Larsen et al. 2002), Sweden (Jorhem et al. 1991; Linde´n et al. 2001), Czech Republic (Ulrich et al. 2001), Slovenia (Doganoc 1996), Finland (Niemi et al. 1991; Tahvonen and Kumpulainen 1994), Poland (Falandysz 1993), or The Netherland (Vos et al. 1986). On the other hand, cadmium levels in pig liver from Croatia (SapunarPostruzˇnik et al. 2001), a neighbor country of Serbia, far exceeded the levels found in this study, i.e. several times higher than maximum set level. According to many reports (Sharma et al. 1982; Linde´n et al. 1999, 2001, 2003; Grawe´ et al. 1997; Sapunar-Postruzˇnik et al. 2001; Oskarsson et al. 2004; Andre´e et al. 2010) cadmium concentrations in animal tissues, especially liver and kidney, are strongly related to the cadmium levels in feedstuffs. In conclusion, the results of the present study show that the levels of cadmium in the liver of pigs, reared under the same conditions, were not influenced by genetic lines. However, the variations in cadmium levels in analysed liver tissues indicate cadmium availability in the local agricultural environment in Vojvodina.
Acknowledgements This research was financially supported by the Ministry of Science and Technological Development, Republic of Serbia, project TR31032. These results are part of project No 114451-2091/2011 (Improvement of meat quality from indigenous and modern pig breeds produced in Vojvodina for the production of traditional dry fermented sausages and dry cured meat products), which is financially supported by the Provincial Secretariat for Science and Technological Development, Autonomous Province of Vojvodina, Republic of Serbia.
References Andre´e S, Jira W, Schwind K-H, Wagner H, Schwa¨gele F. 2010. Chemical safety of meat and meat products. Meat Sci. 86:38–48. Buchanan DS. 1987. The crossbred sire: experimental results for swine. J Anim Sci. 65:117–127. Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Off J Eur Commun. L364:5–24. Dave Oomah B, Berekoff B, Li-Chan ECY, Mazza G, Kenaschuk EO, Duguid SD. 2007. Cadmium-binding protein components of flaxseed: Influence of cultivar and location. Food Chem. 100:318–325.
183
Doganoc DZ. 1996. Lead and cadmium concentrations in meat, liver and kidneys of Slovenian cattle and pigs from 1989-1993. Food Addit Contam. 13:237–241. Doyle JJ, Spaulding JE. 1978. Toxic and essential trace elements in meat – a review. J Anim Sci. 47:398–406. Egan SK, Tao SS-H, Pennington JAT, Bolger PM. 2002. US Food and Drug Administration’s Total Diet Study: intake of nutritional and toxic elements, 1991–96. Food Addit Contam. 19:103–125. Falandysz J. 1993. Some toxic and essential trace metals in swine from Northern Poland. Sci Total Environ. 136:193–204. Friberg L, Piscator M, Nordberg GF, Kjellstrom T. 1974. Cadmium in the environment. 2nd ed. Cleveland (OH): CRC Press. Galal-Gorchev H. 1993. Dietery intake, levels in food and estimated intake of lead, cadmium, and mercury. Food Addit Contam. 10:115–128. Gorsuch TT. 1970. The destruction of organic matter. 1st ed. Oxford: Pergamon Press. Grawe´ KP, Thierfelder T, Jorhem L, Oskarsson A. 1997. Cadmium levels in kidneys from Swedish pigs in relation to environmental factors – temporal and spatial trends. Sci Total Environ. 208:111–122. Henke G, Sachs H, Bohn G. 1970. Cadmium determination by neutron activation analysis of liver and kidneys from children and young people. Arch Toxicol. 26:8–16 (in German). Hermida M, Gonzalez M, Miranda M, Rodrı´ guez-Otero JL. 2006. Mineral analysis in rabbit meat from Galicia (NW Spain). Meat Sci. 73:635–639. Ja¨rup L. 2003. Hazards of heavy metal contamination. British Medical Bulletin. 68:167–182. Ja¨rup L, A˚kesson A. 2009. Current status of cadmium as an environmental health problem. Toxicol Appl Pharmacol. 238:201–208. Jorhem L, Slorach S, Sundstro¨m B, Ohlin B. 1991. Lead, cadmium, arsenic and mercury in meat, liver and kidney of Swedish pigs and cattle in 1984–88. Food Addit Contam. 8:201–211. Larsen EH, Andersen NL, Møller A, Petersen A, Mortensen GK, Petersen J. 2002. Monitoring the content and intake of trace elements from food in Denmark. Food Addit Contam. 19:33–46. Lee H-S, Cho Y-H, Park S-O, Kye S-H, Kim B-H, Hahm T-S, Kim M, Lee JO, Kim C-I. 2006. Dietary exposure of the Korean population to arsenic, cadmium, lead and mercury. J Food Compos Anal. 19:S31–S37. Linde´n A, Olsson I-M, Bensryd I, Lundh T, Skerfving S, Oskarsson A. 2003. Monitoring of cadmium in the chain from soil via crops and feed to pig blood and kidney. Ecotoxicol Environ Saf. 55:213–222. Linde´n A, Andersson K, Oskarsson A. 2001. Cadmium in organic and conventional pig production. Arch Environ Contam Toxicol. 40:425–431. Linde´n A, Olsson I-M, Oskarsson A. 1999. Cadmium levels in feed components and kidneys of growing/finishing pigs. J AOAC Int. 82:1288–1297. Lo´pez-Alonso M, Miranda M, Castillo C, Herna´ndez J, Garcı´ a-Vaquero M, Benedito JL. 2007. Toxic and essential metals in liver, kidney and muscle of pigs at slaughter
184
V.M. Tomovic´ et al.
in Galicia, north-west Spain. Food Addit Contam. 24:943–954. Marzec Z, Schlegel-Zawadzka M. 2004. Exposure to cadmium, lead and mercury in the adult population from Eastern Poland, 1990-2002. Food Addit Contam. 21:963–970. Miranda M, Lo´pez Alonso M, Castillo C, Herna´ndez J, Benedito JL. 2001. Cadmium levels in liver, kidney and meat in calves from Asturias (North Spain). Eur Food Res Technol. 212:426–430. National Research Council. 1998. Nutrient requirements of swine. 10th ed. Washington (DC): National Academy Press. Niemi A, Vena¨la¨inen ER, Hirvi T, Hirn J, Karppanen E. 1991. The lead, cadmium and mercury concentrations in muscle, liver and kidney from Finnish pigs and kidney from pigs in Finland during 1987–1988. Z LebensmUntersuchung Forschung A. 192:427–429. Oskarsson A, Widell A, Olsson I-M, Grawe KP. 2004. Cadmium in food chain and health effects in sensitive population groups. BioMetals. 17:531–534. Robards K, Worsfold P. 1991. Cadmium: Toxicology and analysis: A review. Analyst. 116:549–568. Sapunar-Postruzˇnik J, Bazˇulic´ D, Grubelic´ M, Kubala Drincˇic´ H, Njari B. 2001. Cadmium in animal feed and in foodstuffs of animal origin. Food Technol Biotechnol. 39:67–71. Serbian Regulation 1992a. Pravilnik o kolicˇinama pesticida, metala i metaloida i drugih otrovnih supstancija, hemioterapeutiku, anabolika i drugih supstancija koje se mogu nalaziti u namirnicama [Content of Pesticides, Metals, Metalloids and other toxic substances in foods]. Sluzˇbeni list SRJ, broj 5 [Official Gazette, No 5,]. Serbian Regulation 1992b. Pravilnik o kolicˇinama pesticida, metala i metaloida i drugih otrovnih supstancija, hemioterapeutiku, anabolika i drugih supstancija koje se mogu nalaziti u namirnicama [Content of Pesticides, Metals, Metalloids and other toxic substances in foods]. Sluzˇbeni list SRJ, broj 11 [Official Gazette, No 11]. Serbian Regulation 2002. Pravilnik o kolicˇinama pesticida, metala i metaloida i drugih otrovnih supstancija, hemioterapeutiku, anabolika i drugih supstancija koje se mogu nalaziti u namirnicama [Content of Pesticides, Metals,
Metalloids and other toxic substances in foods]. Sluzˇbeni list SRJ, broj 32 [Official Gazette, No 32]. Schneider JF, Christian LL, Kuhlers DL. 1982. Crossbreeding in swine: genetic effects on litter performance. J Anim Sci. 51:739–746. Sharma RP, Street JC, Shure JL. 1982. Translocation of lead and cadmium from feed to edible tissues of swine. J Food Saf. 4:151–163. Smith C, King JWB. 1964. Crossbreeding and litter production in British pigs. Anim Prod. 6:265–271. StatSoft, Inc. 2008. STATISTICA (data analysis software system), version 8.0. [cited 2010 June 23]. Available from: http://www.statsoft.com/. Tahvonen R, Kumpulainen J. 1994. Lead and cadmium contents in pork, beef and chicken, and in pig and cow liver in Finland during 1991. Food Addit Contam. 11:415–426. Tomovic´ VM, Petrovic´ LjS, Tomovic´ MS, Kevresˇ an ZˇS, Dzˇinic´ NR. 2011. Determination of mineral contents of semimembranosus muscle and liver from pure and crossbred pigs in Vojvodina (northern Serbia). Food Chem. 124:342–348. Ulrich R, Raszyk J, Napravnik A. 2001. Variations in contamination by mercury, cadmium and lead on swine farms in the district of Hodonin in 1994 to 1999. Vet Med (Czech). 46:132–139. Varian. 1989. Flame atomic absorption spectrometry. Analytical methods. Mulgrave Victoria, Australia: Varian Techtron Pty Ltd. Visscher PM, Pong-Wong R, Whittemore CT, Haley CS. 2000. Impact of biotechnology on pig (cross)breeding programmes. Livest Prod Sci. 65:57–70. Vos G, Teeuwen JJMH, van Delft W. 1986. Arsenic, cadmium, lead and mercury in meat, livers, and kidneys of swine slaughtered in The Netherlands during the period 1980–1985. Z Lebensm-Untersuchung Forschung A. 183:397–401. Vromman V, Waegeneers N, Cornelis C, De Boosere I, Van Holderbeke M, Vinkx C, Smolders E, Huyghebaert A, Pussemier L. 2010. Dietary cadmium intake by the Belgian adult population. Food Addit Contam. 27:1665–1673. WHO. 1992. Cadmium. Environmental Health Criteria 134. Geneva: World Health Organisation. Williamson CS, Foster RK, Stanner SA, Buttriss JL. 2005. Red meat in the diet. Nutr Bull. 30:323–355.
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