LATVIA UNIVERSITY OF AGRICULTURE - Latvijas ...

Zane Vincevica-Gaile, Maris KlavinsROOT VEGETABLES FROM LATVIA:QUANTITATIVE ANALYSIS OF TRACE ELEMENTSand Salama, 2006) but results from Finnish studyshowed the following average values of cadmiumcontent: in onions 0.03-0.15 mg kg -1 DM, in carrots0.12-0.28 mg kg -1 DM and in potatoes 0.07 mg kg -1DM (Ekholm et al., 2007). Other study in Romaniashowed that carrot roots may contain cadmium up to3.39 mg kg -1 (Soceanu et al., 2007) but Cd content incarrot roots grown near zinc plant in China reachedup to 9 mg kg -1 DM (Zheng et al., 2007). Organicallygrown potatoes contained very low concentration ofCd (0.006-0.040 mg kg -1 fresh weight) (Bibak et al.,1998).As and Se in vegetables has been detected only infew studies. For example, onion bulbs analyzed in Spaincontained 0.039 mg kg -1 DM of As and 0.010 mg kg -1DM of Se but carrot roots 0.241 mg kg -1 DM of As and0.059 mg kg -1 DM of Se (Matos-Reyes et al., 2010).As and Se content in carrots grown in an industrialarea in Greece was 0.02-0.05 mg kg -1 DM of As and0.02-0.63 mg kg -1 DM of Se (Voutsa and Samara,1998), while As and Se contents in carrot samplesfrom agricultural areas of Greece were detectedbelow the detection limits (Stalikas et al., 1997). Thestudy in Bangladesh revealed important influence ofindustrial pollution, use of pesticides and fertilizerson the potentially toxic element content in differentkind of vegetables. However, in a case of As and alsosome other metals, soil characteristic parameters areof importance, e.g., moisture content of soil, pH, soilgranulometric composition and oxidation/reductionproperties (Alam et al., 2003).Within the European legislation there aremaximum levels set for some metals in root vegetablesand peeled potatoes: for Pb 0.10 mg kg -1 WW (wetweight) and for Cd 0.10 mg kg -1 WW (CommissionRegulation (EC) No.1881/2006). Recalculation ofmean values obtained within the current study fromunits of dry mass to units of wet weight reveals thatmaximum levels of certain contaminants in analyzedroot vegetable samples are not exceeded. Only potatopeel contains Pb above 0.10 mg kg -1 WW; however,peel is not assessed as edible part of vegetables(Table 2).ConclusionsObtained data reveal the importance of the assessmentof element transfer into the food chain and can be auseful tool for the evaluation of consumer safety. Thestudy showed that the presence of trace elements,including potentially toxic elements, in vegetablesgrown in Latvia is detectable and element contentmay vary in a wide range. Element transfer routes andbiochemistry is complicated issue that is affected bynatural environmental factors as well by consequencesof anthropogenic activities. Comparison of elementcontent in edible parts of vegetables and potatopeel revealed that the great part of elements (e.g.,As, Co, Cr, Pb) remain in the peel, however, someelements (e.g., Cd, Se, Zn) are uptaken by plantsand therefore may contaminate food more easily.It has been observed that chemical properties ofelements are of great importance, for example, suchelements as selenium and cadmium has a tendencyto be taken up by plant tissues while other elementsmay remain in compounds that cannot so easily passnatural boundaries such as vegetable peel. Overall,concentrations of trace elements detected in vegetablesamples grown in Latvia are comparable with thedata from other countries with similar environmentalconditions, but detected concentrations are muchlower than those observed in vegetables grown inpolluted areas worldwide. Although within this study itwas discovered that maximum allowed levels of somepotentially toxic elements (e.g., Cd, Pb) in edible partsof root vegetables are not exceeded, for consumersafety reasons regular monitoring of element contentof food crops should be implemented.AcknowledgementsThis work has been supported by the European SocialFund within the project ‘Support for Doctoral Studiesat University of Latvia’.Concentration of potentially toxic elements (Pb and Cd) in analyzed vegetable samples(recalculated in units of wet weight)Table 2Vegetable samplePbCdmg kg -1 WWOnion bulbs 0.0058 0.0035Carrot roots 0.0120 0.0107Potato flesh 0.0188 0.0174Potato peel 0.1746 0.0318Research for Rural Development 2012135