Contamination of Cow Milk by Heavy Metals in Serbia

Background: Dairy cows are exposed to numerous environmental hazards, such as heavy metals. Milk and dairy products could be harmful to humans when maximum tolerable amounts of heavy metals are exceeded. Analysis of heavy metals in milk is important because milk is a source of essential nutrients and is an indicator of environmental contamination. Some heavy metals are essential to maintain proper metabolic activity in living organisms, but at exceeded levels they could be toxic to living organisms. The main objective of the present study was to determine the residue levels of ten heavy metals (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in cow milk in Serbia.Materials, Methods & Results: The experiment was conducted at three farms at Vojvodina district, Serbia. Cows from all three farms were on pasture during spring and summer time. Randomly 50 cows from each farm were taken for this experiment. The cows have similar body condition score they were in their third or fourth lactation and gave approximately the same amount of milk in the previous lactation. Total 150 milk samples were collected from cows during the morning milking, in the period between April to May in 2016. All 150 milk samples were transported to laboratory as soon as possible and analyzed for the heavy metals. Heavy metals were analyzed by Inductance coupled plasma - optical emission spectrometry. Data are presented as mean values ± sd. Statistical analysis was done by one way repeated measures analysis of variance (ANOVA). The level of significance was set at P < 0.05. The highest average concentration in cow milk was determined for Iron (283.9 mg/kg), then for Zinc (60.21 mg/kg) and Copper (4.404 mg/kg), while the lowest concentration was for Cobalt and Lead (less than 0.005 mg/kg).Discussion: Bioaccumulation is one of the biggest problems with heavy metals. Heavy metals residues in milk can be very dangerous for the calves and humans as well. The existence of trace elements and heavy metals in dairy products and milk has been recorded in various countries since it is considered as one of the most dangerous aspects of food contamination. The presence of heavy metals in cow's milk may be attributed to contamination due to exposure of lactating cow to environmental pollution or consumption of contaminated feeding stuffs and water. Heavy metals after intake in cow organism distributed to all organs and glands such as udder. By that, secretory udder tissue gets intoxicated with heavy metals and after that they can be found in milk. After analyses the results in this experiment the highest average concentration of Fe in cow milk it might be because cows were fed with hay from pasture rich in iron between April to May. Some researchers found the amounts of Cu in the milk of individual varied from 0.2 to 0.8 mg/kg. Contrary to this finding, in current study the average value of Cu in cow milk was 4.404 mg/kg. It is found that the highest concentration of Zn in cow milk is 10.75 mg/kg, lower compare to result in current study (60.21 mg/kg). Arsenic (As) concentration was 0.058 mg/kg, cadmium (Cd) was 0.01 mg/kg, cobalt (Co) was 0.002 mg/kg, chrome (Cr) was 0.018 mg/kg, manganese (Mn) was 0.493 mg/kg, nickel (Ni) was 0.119 mg/kg and lead (Pb) was 0.08 mg/kg what is just above recommended values by International Dairy Federation. The results showed that most of the milk samples from the different farm contained all the studied metals with concentration higher than those recommended by International Dairy Federation and Codex for cow milk

Ostaci pesticida u organskim proizvodima

Food from organic production systems in recent years gain increasingly significant place in the market. Awareness of the benefits of the food products that were created with no application of agrochemicals is becoming increasingly prominent. The presence of chemical agents can not be totally excluded, even when applying all the principles of organic production because residues present in the soil, applied long before the mandatory conversion time of five years, may affect the quality of organic products. The aim of this study was to determine the presence of 50 pesticide in vegetables from organic production. The vegetable samples were taken from green markets. Pesticide residues, higher than the detection limit and less than the maximum allowable concentration (MAC) are present in 52%, 23% and 2% respectively for organochlorine, carbamate and organophosphate insecticides, while carbamates were not detected in any sample. MAC is exceeded in one sample of kohlrabi, eggplant, parsley, potatoes, peppers, beets and cabbage, for the content of HCH and metabolites, aldrin and metabolites, endrine, heptachlor and metabolites, phosalone and azinphos-methyl.Poljoprivredni proizvodi iz organskog sistema proizvodnje poslednjih godina imaju sve značajnije mesto na tržištu. Svest ljudi o prednostima ishrane proizvodima koji su nastali uz minimalnu primenu agrohemikalija, postaje sve izraženija. Prisustvo hemijskih sredstava se ne može potpuno isključiti, čak i kada se primenjuju svi principi organske proizvodnje, jer rezidue prisutne u zemljištu aplicirane mnogo pre početka obaveznog vremena konverzije mogu da utiču na kvalitet organskih proizvoda. Cilj ovog istraživanja je utvrđivanje prisustva ostataka perzistentnih i drugih pesticida u povrću iz organske proizvodnje. U uzorcima povrća: blitve, brokolija, bundeve, celera, cvekle, karfiola, kelerabe, krastavca, krompira, kupusa, paprike, patlidžana, peršuna, šargarepe i tikvica, uzetim na novosadskim zelenim pijacama, ispitan je sadržaj ostataka 50 pesticida i njihovih metabolita. Ostaci pesticida, viši od limita detekcije primenjene metode, a manji od maksimalno dozvoljene koncentracije (MDK) su prisutni u 52 %, 23 % i 2 % uzoraka, respektivno za organohlorne, karbamatne i organofosforne insekticide, dok karbamati nisu detektovani ni u jednom uzorku. MDK vrednost je premašena u po jednom uzorku kelerabe, patlidžana, peršuna, krompira, paprike, cvekle i kupusa u pogledu sadržaja HCH i metabolita, aldrina i metabolita, endrina, heptahlora i metabolita, fosalona i azinfosmetila

Prisustvo urea herbicida u kanalskoj vodi

The LC-MS/MS analysis of canal water from Čelarevo and Vrbas was performed for the urea herbicides (chlorotoluron, dimefuron, diuron, ethidimuron, isoproturon, linuron, metabromuron and methabenzthiazuron) residue content from December 2012 to June 2013, with isoproturn-d6 as an internal standard. The herbicides extraction was done by OASIS HLB columns, with the linear coeficcients higher than 0.99 and LOQs of 0.020 μg/L. All the detected concentrations were below maximum acceptable concentrations ( MACs).Izvršena je LC-MS/MS analiza uzoraka kanalske vode, uzorkovane kod Čelareva i Vrbasa u periodu od decembra 2012. do juna 2013. godine, na sadržaj urea herbicida (hlorotoluron, dimefuron, diuron, etudimuron, izoproturon, linuron, metabromuron i metabenztiazuron) uz izoproturon-d6 kao interni standard. Ekstrakcija herbicida izvedena je na OASIS HLB kolonama, sa koeficijentom linearnosti ispitivanih herbicida višim od 0,99 i postignutim LOQ od 0,020 μg/L. Detektovane vrednosti pesticida bile su ispod maksimalno dozvoljenih koncentracija (MDK)

Suzbijanje korova u organskoj poljoprivredi

Organic agriculture as a production system based on ecological production, soil biological activity, biodiversity conservation and use of natural substances and processes is the only certified food production in Serbia. This system provides users of organic products with a guarantee that the end product is the result of consistent farming practices. Since 2010, three laws and a number of regulations underlying the development of this food production system have been adopted. The global organic market has seen a continuous rise in demand for organic products, whereas a relatively slight increase in their supply from organic crop growing areas of Serbia has been recorded. Reasons for the insufficient farmers' interest in organic agriculture include lack of information, lack of intermediate goods, fear of change and, very often, underestimation by conventional producers and professional agrarian circles. An important part of the mosaic-like fear of organic farming among producers is lack of knowledge regarding weed control methods in this production concept. As with other elements of organic farming practices, the basis for weed control rests on preventive action, as well as on direct methods of eliminating undesirable plants from agricultural biotopes.Organska poljoprivreda kao proizvodni sistem baziran ne ekološkoj proizvodnji, biološkoj aktivnosti zemljišta, očuvanju biodiverziteta, uz primenu prirodnih suspstanci i postupaka, jedina je sertifikovana proizvodnja hrane u Srbiji. Korisnicima organskih proizvoda se garantuje da je finalni proizvod rezultat dosledno sprovedene tehnologije gajenja. Od 2010 godine, usvojena su tri zakona i niz pravilnika, koji su osnov za razvoj ovog sistema proizvodnje hrane. Na svetskom tržištu organskih proizvoda, kontinuirano raste potražnja, dok je povećanje ponude ovih proizvoda iz agrosinuzija Srbije, u relativno blagom porastu. Razlozi nedovoljnog interesovanja proizvođača za bavljenje organskom poljoprivredom su neobaveštenost, nedostatak repro materijala, strah od promena i veoma često omalovažavanje od strane konvencionalnih proizvođača i stručne agrarne javnosti. Jedan od važnih elemenata u mozaiku kreiranja straha od organske poljoprivrede među proizvođačima je i nepoznavanje načina suzbijanja korova u ovom proizvodnom konceptu. Kao i u drugim elementima tehnologije gajenja, osnova suzbijanja korova jesu preventivne mere, ali postoje i direktni načini eliminisanja nepoželjnih biljaka iz agrobiotopa

Degradation of linuron in soil by two fungi

Two fungal strains were applied to soil polluted with herbicide in order to determine their degradation potential. Three experimental setups were used. In the first setup, the soil in pots was contaminated by linuron in final concentration of 1 ppm. Suspensions of Phanerocheate chrysosporium and Trichoderma asperellum were applied sepa­rately or in combination. Tomato plantlets were transplanted and chlorophyll content in their leaves was determined at two time points during plant growth. In the second setup in pots, the final concentration of linuron was lower, 0.45 ppm. In the third setup 0.1 ppm of linuron was applied in the field plot. Plantlets of lettuce were transplanted and chlorophyll content was measured as indicator of plant stress. The content of linuron in soil was determined by HPLC. The applied fungal strains significantly reduced toxic effect of 0.45 ppm linuron on plants, which was not the case for 1 ppm linuron. Both fungi, applied separately or in combination, were effective in decreasing the linuron content in the soil. However, in field conditions the combination of both fungi was the most effective. [Projekat Ministarstva nauke Republike Srbije, br. III43010

Screening of Trichoderma strains isolated from rhizosphere samples for laccase production

In this study we screened formerly isolated Trichoderma strains for laccase production on solid media supplemented with two different substrates, ABTS [2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate)] or guaiacol. We detected outstandingly strong colour changes in the case of three Trichoderma strains in this experiment. The strains were identified based on internal transcribed spacer (ITS) sequence analysis as T. asperellum (SZMC 20786 and SZMC 20866) and T. atroviride (SZMC 20780). We also investigated the production of laccase enzymes in the case of these Trichoderma strains in two types of liquid media. The pH dependence of the secreted laccases was determined in cell free ferment broths at pH 3.5, 4, 5, 5.5, 6 and 6.5 adjusted with 25 mM succinate buffer. Laccase activities from liquid cultures were measured with ABTS as substrate. The results showed that the best laccase producer among the investigated Trichoderma strains was T. atroviride SZMC 20780 under these conditions. This strain shows the highest laccase enzyme activity on the second day of incubation in a rotary shaker at 25 °C