Daniel Bajčan

Contamination of wild-grown edible mushrooms by heavy metals in a former mercury-mining area

The aim of this study was to evaluate the contamination of six edible wild species of mushrooms (Boletus pulverulentus, Cantharellus cibarius, Lactarius quietus, Macrolepiota procera, Russula xerampelina and Suillus grevillei) by heavy metals (Hg, Cd, Pb, Zn, Cu, Ni, Cr, Co, Mn and Fe). Mushroom samples were collected from sites contaminated by emissions from mining and processing of polymetallic ores in operation during the period 1969–1993 in Rudňany, southeast Slovakia. The four study sites spanned up to a 5-km distance from the emission source. The collected mushroom samples were analyzed using Flame Atomic Absorption Spectrophotometry and/or Flame Atomic Absorption Spectrophotometry with graphite furnace. Mercury, Cd and, in some samples, also Pb present the highest risks in terms of contamination of the food chain following subsequent consumption. The content of two metals in the dry matter (dm) of the mushrooms exceeded the limits set by the European Union (EU; Cd: 0.5 mg/kg dm, Pb: 1.0 mg/kg dm). The highest mean contents of the eight metals recorded for S. grevillei were 52.2, 2.15, 107, 104, 2.27, 2.49, 81.6 and 434 mg/kg dm for Hg, Pb, Zn, Cu, Ni, Cr, Mn and Fe, respectively. The highest content of Cd was recorded in M. procera (3.05 mg/kg dm) and that of Co in L. quietus (0.90 mg/kg dm). The calculated weekly intake for Hg, Pb and Cd shows that regular consumption of mushrooms from the studied area poses risks to human health.

Assessment of environmental and health risks in former polymetallic ore mining and smelting area, Slovakia: Spatial distribution and accumulation of mercury in four different ecosystems

Former long-term mining and smelting of pollymetallic ores in the Middle Spiš area caused a serious contamination problem of the environment with heavy metals and metalloids, especially mercury (Hg). Several studies have reported concentration of Hg in the area but this paper provides first detailed characterization of Hg contamination of different environmental components in agricultural, forest, grassland and urban ecosystems. The ecosystems are in different distances from emission sources - former mercury and copper smelting plants in NE Slovakia. Total Hg content was studied in soil/substrate samples (n = 234) and characteristic biological samples (Athyrium filix-femina (L.) Roth, Macrolepiota procera (Scop.) Singer, Boletus edulis Bull., Cyanoboletus pulverulentus (Opat.) Gelardi, Vizzini & Simonini, Triticum aestivum (L.), Poa pratensis (L.)) (n = 234) collected in the above-mentioned ecosystems. The level of contamination and environmental risks were assessed by contamination factor (Cf), index of geoaccumulation (Igeo) and potential environmental risk index (PER). To determine the level of transition of Hg from abiotic to biotic environment, bioconcentration factor (BCF) was used. To determine a health risk resulting from regular and long-term consumption of the locally available species, the results of the Hg content were compared with the Provisional Tolerable Weekly Intake (PTWI) for Hg defined by World Health Organization. The results suggest that almost 63% of the area belong to the very high risk category and 80% of the sampling sites shown very high contamination factor. Geoaccumulation index showed that almost 30% of the area is very strongly contaminated and only 8% is not contaminated with Hg. Spearmans correlation relationship confirmed that the values of PER, BCF, Cf and Igeo decreased with an increasing distance from the pollution source. The percentage of contribution to PTWI ranged between 5.76-69.0% for adults and 11.5-138% for children. Mushroom M. procera showed the highest %PTWI among the tested biological samples. Studied ecotoxicological parameters showed high level of health risk for population living in the area. Consumption of the crops grown in the area and mainly edible wild mushrooms might negatively affect the health of the consumers in the long-term.

Antioxidant activity, phenolic content and colour of the Slovak Cabernet Sauvignon wines.

Antioxidants are specific substances that oxidize themselves and in this way they protect other sensitive bioactive food components against destruction. At the same time, they restrict the activity of free radicals and change them to less active forms. Grapes and wine are a significant source of antioxidants in human nutrition. One of the most important group occuring in grapes and wines are polyphenols. Many of phenolic compounds have been reported to have multiple biological activities, including cardioprotective, anti-inflammatory, anti-carcinogenic, antiviral and antibacterial properties attributed mainly to their antioxidant and antiradical activity. Therefore, it is important to know the content of polyphenols and their antioxidant effects in foods and beverages. Twenty-eight Cabernet Sauvignon wine samples, originated from different Slovak vineyard regions, were analyzed using spectrophotometry for the content of total polyphenols, content of total anthocyanins, antioxidant activity and wine colour density. Determined values of antioxidant activity in observed wines were within the interval 69.0 - 84.2% inhibition of DPPH (average value was 78.8% inhibition of DPPH) and total polyphenol content ranged from 1,218 to 3,444 mg gallic acid per liter (average content was 2,424 mg gallic acid.L-1). Determined total anthocyanin contents were from 68.6 to 430.7 mg.L-1 (average content was 220.6 mg.L-1) and values of wine colour density ranged from 0.756 to 2.782 (average value was 1.399). The statistical evaluation of the obtained results did not confirm any linear correlations between total polyphenol content, resp. total anthocyanin content and antioxidant activity. The correlations between total polyphenol content and total anthocyanin content, resp. the content of total anthocyanins and wine colour density were strong. The results confirmed very strong correlations between wine colour density and total polyphenol content, resp. antioxidant activity.

The relationships between content of heavy metals in soil and in strawberries

ABSTRACT The work was aimed at assessment of quality of strawberry based on the contents of heavy metals as well as the possible correlations between selected heavy metals in soil and strawberries. The results revealed that from all observed metals in soil determined in aqua regia only in the case of cadmium the maximum permissible limit in comparison with the limit resulting from the Law No. 220/2004 as well as threshold values proposed by European Commission (EC) (2006) has been exceeded. In our paper the values of cadmium in the soil representing 1.86 to 2.41 times higher values than limit valid in the Slovak Republic (0.7 mg/kg) and 2.6 to 3.38 times higher in comparison to EC (0.5 mg/kg). In our study in 1 M NH4NO3 the values of lead ranged from 0.125 to 0.205 mg/kg representing values exceeded the limit valid in Slovak Republic (0.1 mg/kg) about 0.037–0.105 mg/kg. Despite exceeded values of heavy metals in soil, no values above the limit directly in strawberries when compared to Food Codex of Slovak Republic as well as to Commission Regulation 1881/2006 were recorded. Among the varieties statistically significant differences (P < 0.05) in intake of heavy metals were found.

Vertical Zinc Migration in Various Soil Types

Vertical Zinc Migration in Various Soil Types In this contribution the zinc content in selected soil types and soil reaction on zinc loading in kinetic model conditions with knock-down columns filled with soil samples are evaluated. The total zinc content after their draining, finish and decomposition by HF + HClO4 mixture and its fractions content in extract of 2 mol dm-3 HNO3, in extract of 0.05 mol dm-3 EDTA and in extract of 0.01 mol dm-3 CaCl2 using atomic absorption spectrometry method were determined. The knock-down columns filled with soil samples in model kinetic conditions were used for observation of zinc sorption measure. The maximal water capacity of soils was determined and then solution of 280 mg zinc (ZnSO4.2H2O) per kilogram of soil was applied. The zinc contents in extraction solutions 2 mol dm-3 HNO3, 0.05 mol dm-3 EDTA and 0.01 mol dm-3 CaCl2 in drained 0.05 m high soil columns by atomic absorption spectrometry method were determined. The obtained results were evaluated by mathematical-statistical methods - multiple range analysis and linear regression. Achieved data were compared to allowed limit values. The results show different behavior of individual soil types against zinc loading. The soils showed different properties, where zinc migration to the lower column layers was determined. The accent is given to zinc dynamics in neutral and acid soils. The limit value A (140 mg kg-1) was observed in Luvic Cambisol. The limit value A1 (40 mg kg-1) was observed in Eutric Regosol and Luvic Cambisol in upper layer of soil in column. The obtained results show high mobility of zinc in tested soils and thus its risk for ecosystems.

Copper content in cereals grown in the model condition

The consumption of cereals in Slovakia but also worldwide is increasing by every year. From 30000 to 50000 tons of mercury circulates thought the biosphere that gets into the atmosphere degassing of the earths crust and world oceans. Trace element as copper is one of the most efficient antioxidants in the body, often referred to as an element of beauty. It acts as a powerful catalyst for many enzymes and vitamins, through which already small amounts affects many activities in the body (strengthens immunity, reduces levels of histamine). It accumulates in the barley, beans, cucumber, nuts or milk and so on. The aim of our work was the evaluation of transfer of mercury from sludge to edible part of chosen cereals. The objectives were achieved in simulated conditions of growing pot experiment. We used agricultural soil from the location of Výcapy - Opatovce for the realization of the experiment. The sludge, which was added at various doses, was taken from Central Spis area from locality of Rudňany near the village where minedironore that contains mainly cooper and mercury during last few decades was. We used three types of cereals: barley ( Hordeum sativum L . ) variety PRESTIGE, spring wheat ( Triticum aestivum L . ) variety ISJARISSA and oat ( Avena sativa L . ) variety TATRAN. The length of growing season was 90 days. From the obtained results of two years can be concluded that the accumulation of cooper by seed follows barley ˂ oat ˂ wheat. Even though that the barley is characterized by the highest accumulation of cooper in the seeds, the content did not exceed the maximum level specified by The Codex Alimentarius of the Slovak Republic (CA SR). The results shows that the suitable cultivation of the cereals in localities, which are contaminated with heavy metals, especially by cooper, that the high content of cooper in soil do not pose a risk of accumulation of the metal into the cereal grain.

Methylxanthines and catechines in different teas (Camellia sinensis L. Kuntze) – influence on antioxidant properties

In general, there are four basic types of tea: green (not fermented), black (fermented), oolong and white tea (partially fermented). The differences among these types are in the processing technology, which is largely reflected in their chemical composition. The most influential factor that significantly affects the quality and quantity of substances (biologically active) is the processing temperature, which causes changes in the composition (isomerization and/or transformation). The present paper focuses on monitoring content of three methylxanthines - alkaloids (caffeine, theophylline and theobromine), and seven flavan-3-ols - catechins ((+)-catechin (C), (-)-catechin-3-gallate (C-3-G), (-)-epicatechin (EC), (-)-epicatechin-3-gallate (EC-3-G), (-)-epigallocatechin-3-gallate (EGC-3-G), (-)-gallocatechin (GC) and (-)-gallocatechin-3-gallate (GC 3-G)), which are characteristic for tea. Attention was also given to the assessment of selected antioxidant parameters using spectrophotometric procedures (ABTS - radical cation decolorization assay and Phosphomolybdenum reducing antioxidant power assay) in relation to the determined substances using RP-HPLC/DAD analysis. Based on the results obtained, it can be concluded that a type of tea clearly affects the quality and quantity of the substances that have a positive impact on the consumers health, significantly reflected in the levels of antioxidant active substances determined by the spectrophotometric procedures. The highest content of methylxanthin, catechins, polyphenols and antioxidant substances was recorded in the green tea sample GT3. The highest content of flavonoids and phenolic acids was recorded in the Pu-erh tea sample PT 5.

Herbicidal effect in relation to the accumulation of macroelements and its regulation by regulators of polyamine synthesis.

Stress effects of triazine herbicide on cumulating of important macroelements (phosphorus, potassium, calcium and magnesium) into the grain of barley variety Kompakt, as well as the elimination of its negative effect through the addition of regulators of polyamine synthesis (γ-aminobutyric acid and propylenediamine) were investigated in pot trial. These morphoregulators are degrading products of polyamines and hypothetically after foliar application they should support their biosynthesis which increased level act against stress in plants. Application of the herbicide alone in comparison to control variant reduced the contents of all mentioned macroelements in grain of barley and also in variants, where the mixtures of herbicide with regulators of polyamine biosynthesis were applied, also the values of contents of all macroelements (except of magnesium) in barley grain were reduced (in comparison to this variant). It could be summarized that the presence of regulators in mixtures with triazine herbicide in comparison to control variant had not positive effects on contents of these biogenic elements in grain. By the comparison of variant with the applied herbicide with variants, where also regulators of polyamine synthesis were applied, there was the most positive influence of these mixtures of morphoregulators on statistically non-significant accumulation of phosphorus into generative organs of spring barley and in the case of positive accumulation of magnesium into these plant tissues there was statistically significant relation only after application of mixtures of herbicide with propylenediamine. Positive influence on accumulation of calcium was evaluated only after using of mixtures of herbicide with propylenediamine (statistically significant relation was recorded at the dose 29.6 g.ha -1 ).

EFFECT OF NITROGEN APPLICATION ON SELECTED NUTRITIONAL COMPONENTS OF POTATO TUBERS

In this work the influence of graduated nitrogene fertilizers doses to the soil on starch and vitamin C formation in potato tubers grown in field conditions in locality Veľka Calomija was studied. The investigated potato cultivar Solara is medium early potato cultivar. The determined average starch content in potato samples ranged in interval 12,426 % - 15,084 %, while the highest starch content was determined in variant 1 (without nitrogen addition to the soil). The starch content in potato tubers was decreased in order: variant 1 (15,084 %) > variant 2 (14,427 %) > variant 3 (14,378 %) > variant 4 (14,023 %) > variant 5 (12,603 %) > variant 6 (12,426 %). The content of C vitamin was increased with the graduated nitrogen doses to the soil only till variant 4 and after that the content of vitamin C was decreased. The average content of C vitamin ranged in interval 3,786 - 6,225 mg.kg-1 of fresh matter.doi:10.5219/220