Heavy metals in onion (Allium cepa L.) and environmental and health risks.

This study aimed to determine heavy metal content in soil and selected cultivars of onion. Cd content in soil exceeded the limit 2.43 times. Bioavailable forms of Pb and Cd in soil exceeded the critical value 5.9 times and 1.9 times, respectively. Analysed cultivars were not bioaccumulators of monitored heavy metals. However, Pb and Cd content in cultivars Nanas F1, Kappa and Daytona F1 exceeded the maximum limit set by the EU regulation. For Pb this was also the case for the Spirith cultivar. Based on health risk assessment it could be concluded that moderate consumption of onions from the studied localities does not pose a risk to consumers.

Impact of old environmental burden in the Spis region (Slovakia) on soil and home-grown vegetable contamination, and health effects of heavy metals.

Due to several centuries of ongoing mining activities, Middle Spis (Slovakia) is one of the areas with a damaged environment. The contents of Fe, Mn, Zn, Cu, Ni, Pb, Cd, and Hg were determined in the soils and home-grown vegetables (potatoes, carrots, tomatoes). Except for Pb, the contents of heavy metals in the soils of some plots were higher than the limit values. Based on the values of Contamination factor (Cf), Degree of contamination (Cdeg), Geo-accumulation index (Igeo), and Pollution load index (PLI), very high Fe, Cd, and Hg contamination (Cf ≥ 6), very high soil contamination (Cdeg ≥ 20), extremely heavy Fe and Hg contamination (Igeo > 5), resp. moderately pollution to non-pollution (1 < PLI ≤ 2) was found in all plots. In vegetable samples, the maximum levels were exceeded for Cu, Pb, Hg (potato), Pb (carrot, tomato), and Hg (carrot, plot E). Bioaccumulation factor values BAF > 1 were for Cu (carrots, potatoes). Estimated daily intake values for all heavy metals were lower than their tolerable daily intake. Chronic daily intake of heavy metals ranged 2.495E-06 (Hg)-0.1416 (Fe) mg/kg/day. Based on Hazard index values, potato consumption poses a risk (0.8068-1.3057). The results showed that the monitoring of soils and cultivated production is necessary for the investigated area.

Molecular Shield for Protection of Buckwheat Plants from UV-B Radiation.

Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.) and common buckwheat (Fagopyrum esculentum Moench) are adapted to growing in harsh conditions of high altitudes. Ultraviolet radiation at high altitudes strongly impacts plant growth and development. Under the influence of ultraviolet radiation, protecting substances are synthesized in plants. The synthesis of UV-B defense metabolites is genetically conditioned, and their quantity depends on the intensity of the ultraviolet radiation to which the plants and plant parts are exposed. These substances include flavonoids, and especially rutin. Other substances with aromatic rings of six carbon atoms have a similar function, including fagopyrin, the metabolite specific for buckwheat. Defensive substances are formed in the leaves and flowers of common and Tartary buckwheat, up to about the same concentration in both species. In comparison, the concentration of rutin in the grain of Tartary buckwheat is much higher than in common buckwheat. Flavonoids also have other functions in plants so that they can protect them from pests and diseases. After crushing the grains, rutin is exposed to contact with the molecules of rutin-degrading enzymes. In an environment with the necessary humidity, rutin is turned into bitter quercetin under the action of rutin-degrading enzymes. This bitterness has a deterrent effect against pests. Moreover, flavonoids have important functions in human nutrition to prevent several chronic diseases, including obesity, cardiovascular diseases, gallstone formation, and hypertension.

Changes in Antioxidant Properties and Phenolics in Sweet Potatoes (Ipomoea batatas L.) Due to Heat Treatments.

Processing is one of the most crucial factors affecting polyphenol content in foods. Therefore, the study is aimed at the evaluation of heat treatment effects (microwaving, steaming, baking, and boiling) on the content of chlorogenic acids, total polyphenols, and antioxidant activity of three varieties of sweet potato with different flesh colors (Beauregard­orange-fleshed, O'Henry­white-fleshed, 414-purple­purple-fleshed). According to high performance liquid chromatography analysis, chlorogenic acid was the predominant chlorogenic acid in sweet potatoes. Obtained results also suggested the purple-fleshed variety (414-purple) had significantly (p < 0.05) higher total polyphenol content and thus the highest antioxidant activity. Heat treatment positively influenced the chlorogenic acid content, total polyphenols, and antioxidant activity of sweet potatoes. Among the used methods, steaming had the greatest effect on the chlorogenic acids and total polyphenols, while microwaved samples showed the highest antioxidant activity (DPPH). The content of chlorogenic acids and total polyphenols decreased in the order of steaming > baking > microwaving > boiling > raw. However, the individual varieties differed not only in the flesh color but also in the reaction to the used heat treatment methods. Spearman's correlation coefficient showed a strong correlation between chlorogenic acid and antioxidant activity.

Heavy Metals Presence in the Soil and Their Content in Selected Varieties of Chili Peppers in Slovakia.

Capsicum chili peppers are popular vegetables in Slovakia. They provide a supply of health-promoting substances, but contaminated vegetables can pose a serious health risk to the people who consume them. Therefore, the aim of this study was to determine the content of heavy metals (Mn, Zn, Cr, Cu, Ni, Cd, Pb and Hg) in the soil as well as in selected varieties of the genus Capsicum grown in southern Slovakia. The results were compared with the limit values given by the Law no. 220/2004 (valid in the SR) as well as threshold values proposed by the European Commission (EC) (2006). The gained result showed that the total content of Cd (1.64 mg/kg) as well as the available mobile forms of Cd (0.12 mg/kg) and Pb (0.26 mg/kg) was exceeded on the soil on which Capsicum cultivars were grown. The limit values of other monitored heavy metals (Mn, Zn, Cr, Cu, Ni, and Hg) were not exceeded. The studied species of the genus Capsicum did not accumulate monitored heavy metals. It can be stated that consumption of chili peppers does not pose any risk for human health.

Hygienic quality of soil in the Gemer region (Slovakia) and the impact of risk elements contamination on cultivated agricultural products.

The Gemer region (Slovakia) belongs to areas with a high concentration of risk elements. The contents of Cu, Ni, Pb, Cd, Hg and Mn were determined in soils and cultivated agricultural production from lands in three cadastres of the Gemer region (Henckovce (48.713845, 20.426189) and Nizná Slaná (48.717373, 20.4208423), cultivated crop-spring triticale; Gemerská Poloma (48.704523, 20.487645), cultivated crop-maize). Bioavailable forms of Pb (0.306-0.532 mg/kg) and Cd (0.104-0.154 mg/kg), pseudototal forms of Cd (3.07-3.98 mg/kg) and Hg (0.484-2.18 mg/kg) represented the highest risk in soils. The highest contents of Pb (Cd, Hg) were in maize from Gemerská Poloma: 0.898 (0.081, 0.399) mg/kg DM. Soils were classified based on several indicators of soil contamination. The highest values of indicators are: Contamination factor (Cf 29.1-Hg), Degree of contamination (Cdeg 51.5), Potential ecological risk factor (Er 1163-Hg), Potential ecological risk index (RI 1,520), Pollution load index (PLI 4.76), Geo-accumulation index (Igeo 5.60-Hg). All indicators concerned the lands of Henckovce and Gemerská Poloma, RI also concerned the land of Nizná Slaná. Bioaccumulation factor (BAF) was calculated to assess the plant's ability to absorb the risk element. For both crops and all risk elements, BAF values were < 1. Obtained results indicate heavy metal contamination of soils, therefore monitoring of soils in investigated area is necessary.

Concentrations of Phenolic Acids Are Differently Genetically Determined in Leaves, Flowers, and Grain of Common Buckwheat (Fagopyrum esculentum Moench).

Common buckwheat (Fagopyrum esculentum Moench) is a valuable source of proteins, B vitamins, manganese, tryptophan, phytochemicals with an antioxidant effect, and the natural flavonoid rutin. Due to its composition, buckwheat supports the human immune system, regulates blood cholesterol, and is suitable for patients with diabetes or celiac disease. The study aimed to compare the allocation of selected phenolic acids (neochlorogenic acid, chlorogenic acid, trans-caffeic acid, trans-p-coumaric acid, trans-sinapic acid, trans-ferulic acid) and flavonoids (rutin, vitexin, quercetin, kaempferol) in the leaves, flowers, and grain of buckwheat cultivars of different origin. The content of individual phenolics was determined by the HPLC-DAD method. The results confirmed the determining role of cultivar on the relative content of chlorogenic acid, trans-caffeic acid, trans-sinapic acid, vitexin, and kaempferol in buckwheat plants. A significantly negative correlation among concentrations of phenolic acids in different common buckwheat plant parts shows that there are different mechanisms of genetic influences on the concentration of phenolic substances in common buckwheat flowers, leaves, and grain. These differences should be taken into account when breeding buckwheat for a high concentration of selected phenolic substances.

Effects of Adding Legume Flours on the Rheological and Breadmaking Properties of Dough.

The influence of the addition of four legume flours, chickpea, broad bean, common bean and red lentil (in amounts of 5%, 10% and 15% to a wheat-rye composite flour (50:50:0-control flour), in ratios of 50:45:5; 50:40:10; 50:35:15) was studied by analyzing the rheological properties of dough in order to further exploit the functionality of legume flours in bakery products. The rheological properties of dough were monitored using a Mixolab 2. A Rheofermentometer F4 was used to check the dough fermentation, and a Volscan was used for evaluating the baking trials. The addition of different legume flours in the mixtures resulted in different viscoelastic properties of the dough. The results showed a weakening of the protein network depending on the amount of legume flour added and on the specific legume flour. On the contrary, all samples with a higher proportion of legume flour showed an increased resistance to starch retrogradation. All flours had the ability to produce a sufficient volume of fermenting gases, with the exception of flours with a higher addition of broad bean flour, and the baking test confirmed a lower bread volume for bread with this addition. The results of the sensory evaluation indicated that legume flour additions resulted in breads with an acceptable sensory quality, in the case of additions of 5% at the same level as the bread controls, or even better. The aromas and flavors of the added non-cereal ingredients improved the sensory profile of wheat-rye bread. Breads with additions of chickpea, common bean and broad bean had a considerable proportion of darker colors in comparison to the control bread and bread with red lentil.

Comparison of Heavy Metal Intake by Different Species of the Genus Allium L.

Allium vegetables belong to the most widespread and commonly grown vegetables in Slovakia. In this study, we dealt with the content of selected heavy metals (Zn, Mn, Cr, Cu, Ni, Pb, and Cd) in cultivated garlic (Záhorský, Lukan, Makoi), onion (Amika, Red Matte, Diamant), and leek (Bavaria, Golem, Tango). We determined the total content of heavy metals (aqua regia), and available-mobile forms of heavy metals (1 M NH4NO3) in soils. Analytical final procedure was flame AAS. The results were compared with the limit values given by the Law no. 220/2004 (valid in the SR) as well as threshold values proposed by the European Commission (EC) (2006). Gained result showed that the total content of Cd (1.26 mg.kg-1) as well as the available mobile forms of Cd (0.16 mg.kg-1) and Pb (0.64 mg.kg-1) was exceeded on the soil on which Allium species were grown. Determined contents of heavy metals in garlic were in the range of 0.03-0.07 mg Cd.kg-1 FM (fresh matter), 0.02-0.11 mg Pb.kg-1 FM (fresh matter), in onion ranged from ND (not detected) to 0.03 mg Cd.kg-1 FM (fresh matter), 0.09-0.2 mg Pb.kg-1 FM (fresh matter), and in leek were in the range of, 0.07-0.13 mg Cd.kg-1 FM (fresh matter), and 0.3-0.5 mg Pb.kg-1 FM (fresh matter). Based on the obtained BAF values, we can conclude that the genus Allium does not belong to the accumulator of evaluated hazardous metals. Safe food production requires constant monitoring of hazardous metals in raw materials of plant origin, as these metals can have serious negative effects on human health.

Accumulation and environmental risk assessment of heavy metals in soil and plants of four different ecosystems in a former polymetallic ores mining and smelting area (Slovakia).

Heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in soils and plants of four different ecosystems (forest, grassland, agro and urban ecosystem) at different distances from the source of the pollution were analyzed in order to assess and compare soil contamination in the various ecosystems and determine the potential accumulation of plants depending on the place they inhabit. Correlation relationships among heavy metals in soils differ depending on the ecosystem, and between soil and plant, the heavy metals showed significant correlation for Cu, Mn, Ni, Pb and Zn. Contamination factor (Cf), degree of contamination (Cd) and pollution load index (PLI) were used in order to determine the level of environmental contamination of the study area. All studied ecosystems were rated as moderately contaminated (except agroecosystem, which was found as low contamination ecosystem) according to Cd and extremely polluted according to PLI. The highest pollution in both cases was found in urban ecosystem, and Cd, Cu and Fe were determined as the biggest pollutants.

Environmental Contamination by Heavy Metals in Region with Previous Mining Activity.

Due to its status as one of the most contaminated regions in Slovakia, 45 soil and plant samples were collected in the Middle Spis region. In soil, the exchangeable soil reaction, humus content and heavy metals content (Zn, Cd, Cu, Pb, Hg) were determined. Total content of heavy metals (TC-HMs) and content of mobile forms (MF-HMs) in soil, as well as metal content in plants, were determined by atomic absorption spectrometry. The concentration ranges for total Zn, Cd, Cu, Pb and Hg in soil were 33.1-953, 0.65-6.73, 11.0-913, 26.5-165 and 0.28--415 mg/kg, respectively. The overall concentration ranges of these metals in plants of two types (Athyrium filix-femina L. and Poaceae herbs) were 12.4-158.6, 0.10-1.63, 3.34-85.7, 0.09-29.7 and 0.01-12.8 mg/kg, respectively. Despite the values of Zn, Cd, Cu, Pb and Hg content in the soil exceeding limit values, only the Hg content in plants presented an ecological risk.

Potatoes - A crop resistant against input of heavy metals from the metallicaly contaminated soil.

The objective of our study was to assess the extent of accumulation of cadmium, lead and zinc in potato tubers depending on the concentration of these heavy metals in soil and to evaluate the resistance of 11 cultivars of potato cultivated in 5 localities of the Slovakia against input of these heavy metals into the consumption part of potato. Contents of Cd (Pb, Zn) in soil were 0.94-2.54 (18.03-24.90, 35.71-72.40) mg/kg in soil extract by aqua regia and 0.030-0.188 (0.149-0.356, 0.052-0.238) mg/kg in soil extract by NH4NO3. The contents of Cd, Pb, and Zn were determined in potatoes in extracts of freeze-dried samples and expressed in mg/kg of fresh matter (FM). Determined contents of heavy metals were in the range of ND-0.058 mg Cd/kg FM, 0.020-0.630 mg Pb/kg FM, 1.836-3.457 mg Zn/kg FM, resp. The statistically significant correlation between heavy metal content in soil and its content in potato tubers were confirmed only: cv. Laura - Spissky Stvrtok (Cd), cv. Red Anna - Odorin (Pb) and Marabel, Red Anna - Odorin, cv. Marabel - Belusa, cv. Volumia - Imel (Zn).

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

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.

Changes of Polyphenolic Substances in the Anatomical Parts of Buckwheat (Fagopyrum esculentum Moench.) during Its Growth Phases.

In this study the changes of total polyphenolics in different anatomical parts (stems, leaves, flowers and seeds) of common buckwheat (Fagopyrum esculentum Moench.) during vegetation period were analysed. The content of total polyphenolics was evaluated in growth phase I (formation of buds), phase II (at the beginning of flowering), phase III (full blossoming) and phase IV (full ripeness). In all growth phases (GP) the stems and leaves were evaluated and statistically significant differences in polyphenolics content between the two parts were confirmed. Statistically significant differences (p < 0.01) in polyphenolics content (in GP II and III) between stems and leaves; and between stems and flowers were found. In flowers an average of 13.8 times higher and in leaves 6 times higher concentration of polyphenolics in comparison with stems was measured. In GP III the content of polyphenolics in common buckwheat was following: flowers > leaves > achene > stems. In flowers an average of 11.9 times higher, in leaves 8.3 times higher and in achenes 5.9 times higher contents of polyphenolics compared with stems were found. In GP III and IV (leaves, achenes, stems) the leaves contained in average 20 times higher and achenes 5.6 times higher polyphenolics than stems.

Effect of peeling and three cooking methods on the content of selected phytochemicals in potato tubers with various colour of flesh.

The impact of peeling and three cooking treatments (boiling, baking and microwaving) on the content of selected phytochemicals in white-, yellow-, red- and purple-fleshed potatoes was investigated. Ascorbic acid and chlorogenic acid contents were determined by HPLC-DAD, total anthocyanin content by pH-differential spectrophotometry, glycoalkaloid, α-chaconine and α-solanine contents by HPLC-ESI/MS/MS. All cooking treatments reduced ascorbic and chlorogenic acid contents, total glycoalkaloids, α-chaconine and α-solanine with the exception of total anthocyanins. The losses of ascorbic and chlorogenic acids were minimised with boiling and total anthocyanin levels retained the highest. Boiling of peeled tubers decreased contents of total glycoalkaloids (α-chaconine and α-solanine) and appeared as the most favourable among the three tested methods. Moreover, due to higher initial levels, red- and purple-fleshed cultivars retained higher amounts of antioxidants (ascorbic acid, chlorogenic acid and total anthocyanin) after boiling and may be healthier as compared with white or yellow cultivars.

Effect of a polyamine biosynthesis inhibitor on the quality of grape and red wine.

BACKGROUND: The quality of berries and red wines is influenced by the cultivar. The aim of this study was to determine the effect of a polyamine biosynthesis (PA) inhibitor on some red grapevine cultivars with a genetically lower quality of grapes and wines. O-Phosphoethanolamine was used as a PA inhibitor because of its positive effect on the quality of some small berries. RESULTS: The PA inhibitor at a foliar dose treatment of 7.0 g ha(-1) significantly increased the peroxidation inhibition of berries (1.16- to 1.56-fold), the color density (from 1.66% to 69.14%) and the sensory quality of the wines with a lower genetically programmed color quality (André, Saint Laurent and Zweigeltrebe), but not the higher-quality Alibernet variety. The PA inhibitor predominantly decreased the total phenolic and anthocyanin contents (from 37.0% to 27.5%), and it significantly decreased the contents of free polyamines in all varieties-very dramatically in Saint Laurent grapes (17.16- to 1.58-fold). CONCLUSIONS: Foliar treatment of red grapevine varieties of a low quality, using O-phosphoethanolamine, can help produce higher-quality wines.