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

Polyphenols and phenolic acids in sweet potato (Ipomoea batatas L.) roots

Sweet potato (Ipomoea batatas L.) is one of the most important food crops in the world. They are rich in polyphenols, proteins, vitamins, minerals and some functional microcomponents. Polyphenols are bioactive compounds, which can protect the human body from the oxidative stress which may cause many diseases including cancer, aging and cardiovascular problems.The polyphenol content is two to three times higher than in some common vegetables. Total polyphenols (determined spectrophotometrically) and phenolic acids (i.e. caffeic acid, chlorogenic acid and isomers - using high performance liquid chromatography) contents were determined in three varieties of sweet potatoes (O´Henry - white, Beauregard-orange and 414-purple). Phenolic compounds contents were determined in raw peeled roots, jackets of raw roots and water steamed sweet potato roots. For all analysis lyophilised samples were used. Total polyphenol content ranged from 1161 (O´Henry, flesh-raw) to 13998 (414, peel-raw) mg.kg-1 dry matter, caffeic acid content from the non-detected values (414, flesh-raw) to 320.7 (Beauregard, peel-raw) mg.kg-1 dry matter and 3-caffeoylquinic acid content from 57.57 (O´Henry, flesh-raw) to 2392 (414, peel-raw) mg.kg-1 dry matter. Statistically significant differences (p ≤0.05) existed between varieties, morphological parts of the root, or raw and heat-treated sweet potato in phenolic compounds contents

The cadmium intake of selected legumes in model conditions

The work is to evaluate the extent of risk transfer of heavy metals from soil burdensome to their different levels of consumption of selected parts of the crop. The goal to be achieved in conditions of simulated vegetation pot experiments. To implement the experiment, we used the agricultural soil of land site Výčapy - Opatovce. The experiments use two types of leguminous plants: Faba beans (Faba vulgaris M.), a variety MERLIN lentil dishes (Lens esculentum) variety NELKA. In one experimental tank was weighed 5 kg of soil mixed with 1 kg of silica sand, and the bottom of the container we put a small drainage layer of gravel. Within each container, we applied the calculated dose of the basic fertilizer, as well as various amounts of soluble salts of cadmium observed. Crops are harvested when fully ripe and the  wet mineralization of plant samples was determined by heavy metals AAS method for device VARIAN 240FS. Significant ratio of cadmium is in the aboveground biomass of the legumes. Lentils take into aboveground biomass much more cadmium than  faba beans. The cadmium content in the first two variants is significantly lower than in the next two in both crops. We may conclude that the faba beans, and lentils to accumulate an increased amount of cadmium in soil in a relatively large amount of seeds. Although it is clear that Faba bean received cadmium content was compared with more lentils. Due to the significant accumulation of Cd by plants lentils and excessive production of the aboveground biomass is potentially usable lens as fytoremediation crop recovery for metalic polluted soils

Heavy metals determination in edible wild mushrooms growing in former mining area - Slovakia: Health risk assessment

The aim of the paper is to assess a contamination level of forest substrates and aboveground parts of edible wild mushroom (M. procera (Scop.) Singer, B. recitulatus Schaeff., C. cibarius Fr., S. grevillei (Klotzsch) Singer, A. campestris L., R. xerampelina (Schaeff.) Fr., L. salmonicolor R. Heim & Leclair, C. gibba (Pers. Ex Fr.) Kumm., X. chrysenteron (Bull.) Quél., M. oreades (Bolton) Fr.; n = 70) by heavy metals (Cd, Cu, Pb and Zn). The studied location was a broader surroundigs of the historical mining and metal processing area of Banská Bystrica. The collected mushroom samples and underlying substrate samples were analysed using Flame Atomic Absorption Spectrofotometry and Flame Absorption Spectrophotometry with graphite furnace. Bioaccumulation factors (BAF) for individual species and their anatomical parts were calculated from the results obtained. In order to assess a health risk resulting from regular consumption of the mushrooms, provisional tolerable weekly intake (PTWI) was calculated from the results of the monitored heavy metal concentration. Limit values for the studied contaminants (Cd: 0.49 mg.kg-1 and Pb: 1.75 mg.kg-1 for an individual with an average weight of 70 kg) are defined by FAO and WHO. Our results indicate that S. grevillei has a high bioaccumulation ability of Cd. It was confirmed by bioaccumulation factors (BAFH = 3.47 and BAFRFB = 2.30). The PTWICd value was exceeded by 4.11 times. A similar situation occurred in the case of Pb where the highest bioaccumulation factor (BAFH = 0.24 and BAFRFB = 0.19) was also recorded in the samples of S. grevillei and the PTWIPb value was exceeded by 1.35 times. In general, it can be stated that a consumption of edible wild mushrooms represent a relatively small risk of negative impact on the health of consumers

The heavy metals content in wild growing mushrooms from burdened Spiš area

In this work, we evaluated the rate of entry of heavy metals into the edible parts of wild mushrooms, from central Spiš area. The area is characterized by extremely high content of heavy metals particularly mercury in abiotic and biotic components of ecosystems. The toxicity of heavy metals is well known and described. Known is also the ability of fungi to accumulate contaminants from substrates in which mushrooms grow. We have collected commonly consumed species of mushrooms (Russula vesca., Macrolepiota procera, Lycoperdon pyriforme, Lecinum piceinum, Boletus reticulatus). Sampling was conducted for two years 2012 and 2013. The samples taken mushrooms and substrates on which to grow, we determined heavy metal content (Cd, Pb, Cu), including total mercury content modified by atomic absorption spectrometry (AMA - 254). In the substrate, we determined the humus content and pH value. The heavy metal content in soils were evaluated according to Law no. 220/2004 Z.z The exceedance limit values of Cd, Pb, Cu and Hg was recorded. Most significantly the respective limit was recorded in soil samples in the case of mercury. The determined concentration Hg was 39.01 mg.kg-1. From the results, we evaluated the degree of ability to bioaccumulate heavy metals different kinds of fungi. We also evaluated the health safety of the consumption of these fungi on the comparison with the limit values provided in the food code of SR. We recorded a high rate of accumulation of mercury in the species Boletus reticulatus and Macrolepiota procera. For these types we recorded the most significant than allowed concentrations of mercury in mushrooms. The highest recorded concentration reached 17.64 mg.kg-1 Hg in fresh matter. The limit value was exceeded also in the case of copper. We do not recommend to increased consumption of wild mushrooms in the reference area

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 earth's 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 Výčapy - Opatovce for the realization of the experiment. The sludge, which was added at various doses, was taken from Central Spiš 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 consumer's 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

Determination of heavy metals concentration in raw sheep milk from mercury polluted area

The paper focuses on determining the content of monitored contaminants (Cd, Cu, Hg, Pb and Zn) in 53 samples of raw sheep milk collected in 2013 and 2014 on the sites Poráč and Matejovce nad Hornádom (middle Spiš). The area is characterized by historical mining and metalworking activity (mining and processing of polymetallic ores rich in Hg, Cd and Pb). Currently, the area is one of the most mercury contaminated areas in Central Europe. All statistical analyses were carried out using the statistical software Statistica 10.0 (Statsoft, USA). Descriptive data analysis included minimum value, maximum value, arithmetic mean and standard deviation. The results of the studied contaminant content show that the limit value for cadmium (10 μg.kg-1) was exceeded in 25 samples. In the case of lead, the limit value of 20 μg.kg-1 was exceeded in 16 cases. The limit value for copper (0.4 mg.kg-1) was exceeded in one case. The limit value for zinc is not defined by a legislative standard. The risk level of the studied contaminants in the samples of raw sheep milk decreases as follows: Cd > Pb > Hg > Cu > Zn. It can be concluded that frequent and long-term consumption of the raw sheep milk originating from the studied sites poses a health risk. The content of the contaminants in the milk and their eventual transition into dairy products should be monitored over a longer term in more detail

Antioxidant properties, total phenolic and total flavonoid content of the Slovak white wines - welschriesling and chardonnay

The biologically active compounds in wines, especially phenolics, are responsible for reduced risk of developing chronic diseses (cardiovascular diseases, cancer, diabetes, Alzheimer disease, etc.), due to their antioxidant activities. Twenty six Slovak white wines, produced from different geographical origins, were examined in this study. The antioxidant activity, total phenolic and flavonoid contents of two types monovarietal wines - Welschriesling and Chardonnay were evaluated. All three mentioned parameters were determined by UV-VIS absorption spectrometry. The results showed that both types of Slovak white wines were high in polyphenols (average content was 303.2 mg GAE.L-1 in Welschriesling, resp. 355.6 mg GAE.L-1 in Chardonnay) and flavonoids (average content was 51.9 mg CE.L-1 in Welschriesling, resp. 60.1 mg CE.L-1 in Chardonnay), as well as a high antioxidant activity (average value was 35.0% inhibition of DPPH in Welschriesling, resp. 43.3% inhibition of DPPH in Chardonnay), comparable to the wines produced in other regions in the world. Among the white wines, Chardonnay had higher content of total polyphenols, as well as flavonoids and higher values of antioxidant activity. Our results confirmed very strong linear correlations between all three analysed parameters (TPC, TFC and AA): TPC and TFC (r = 0.818), AA and TPC (r = 0.699), resp. TFC and AA (r = 0.693)

THE EFFECT OF RATIONALIZATION OF GROWING SYSTEMS ON INTAKE OF IRON, POTASSIUM INTO BARLEY GRAIN

The influence of applied inorganic nutrients in soil, the method of tillage (conventional and minimalization) on accumulation of Fe and K into the grain of selected varieties of barley was observed. Small-parcel experiments were carried out on fields with size 14 m2 in three parallels. Four levels of fertilization were done: 1) control – not fertilized variant; 2) N70 + P4,36 + K16,6; 3) N60 + P22,7 + K36; 4) N60 + P22,7 + K36 + Ca25. Fe, K in grain of barley were mineralized by the method of Koppová and their content was assessed by the method of flame AAS at instrument VARIAN 240FS. Content of Fe in dry matter of barley grain in analyzed samples were v interval 34.7-109.0g.kg-1 and of potassium 293,1-658,9g.kg-1. Application of macro elements (N, P, K) into the soil had on the accumulation of Fe into the barley grain reduction effect (beside KM2084 variety) and contrary, in comparison with control variant increased influence on intake of mentioned element in winter varieties (beside variety Malwinta) not dependent on the method of amendments of soil by tillage. Addition of CaCO3 in fertilizers affected with contrary - reducing effect of contents Fe and K in barley grain