Abstract
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 Nižná 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 (C
f
29.1—Hg), Degree of contamination (C
deg
51.5), Potential ecological risk factor (E
r
1163—Hg), Potential ecological risk index (RI 1,520), Pollution load index (PLI 4.76), Geo-accumulation index (I
geo
5.60—Hg). All indicators concerned the lands of Henckovce and Gemerská Poloma, RI also concerned the land of Nižná 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.
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 (Beauregard—orange-fleshed, O’Henry—white-fleshed, 414-purple—purple-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.
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.
As a consequence of environmental quality changes as well as changes in our population's lifestyle, there is rapidly increasing variability and many so-called lifestyle disorders, allergies, and food ...intolerances (also known as non-allergic food hypersensitivity). Unhealthy eating practices, an inappropriate food composition with an excessive energy intake, a high intake of saturated fats, simple sugars, and salt, as well as an inadequate intake of fibre, vitamins, and substances with preventive effects (such as antioxidants), are some of the factors causing this detrimental phenomenon. Enhanced consumption of plant foods rich in valuable secondary metabolites such as phenolic acids and flavonoids with the benefit on human health, food research focused on these components, and production of foods with declared higher content of biologically active and prophylactic substances are some ways how to change and improve this situation. A unique class of hydroxylated phenolic compounds with an aromatic ring structure are called flavonoids. One unique subclass of flavonoids is quercetin. This phytochemical naturally takes place in fruits, vegetables, herbs, and other plants. Quercetin and its several derivates are considered to be promising substances with significant antidiabetic, antibacterial, anti-inflammatory, and antioxidant effects, which could also act preventively against cardiovascular disease, cancer, or Alzheimer's disease.
Phenolic compounds (total polyphenol content – TPC, chlorogenic acid – CGA, neochlorogenic acid – neoCGA, cryptochlorogenic acid – cryptoCGA) and the antioxidant activity (AA) by DPPH and FRAP ...methods were determined in raw peel and flesh of sweet potatoes (white cv. Japanese, orange cv. Beauregard), and in heat-treated flesh (steamed, boiled, microwaved, baked). The TPC in raw orange-fleshed sweet potatoes ranged from 1126 (Croatia – Beauregard) to 3248 (Austria – Beauregard) mg/kg dry weight. Heat treatment significantly increased the CGA and neoCGA content. CryptoCGA in heat-treated samples varied from 5.53 (microwaved Croatia – Japanese) to 119 (steamed Austria – Beauregard) mg/kg dry weight. Higher AA-DPPH was observed in all heat-treated samples, except for microwaved Egypt – Beauregard and Austria – Beauregard, boiled Egypt – Beauregard, and baked Austria – Beauregard samples. The AA-FRAP levels in the Croatia -Japanese, USA – Beauregard, Austria – Beauregard samples increased after all heat treatments. The amount of bioactive compounds and their antioxidant properties in sweet potatoes were both significantly increased by heat treatments.
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•Sweet potatoes are one of the crops with a high potential for human nutrition.•They contain several xenobiotics, including phenolic substances such as anthocyanins, flavonoids, and phenolic acids.•Heat treatment methods (steaming, baking, boiling, microwaving) had a positive effect on the content of bioactive compounds.
The objective of this paper was to examine the total polyphenols, vitamin C and capsaicin contents of pepper (varieties: Garam F1, Alma, Poseidon, Promontor, Slovakia, Claudius, Bhut Jolokia, ...Serrano, and Candlelight) and their correlation with the antioxidant activity by using the high performance liquid chromatography and Folin-Ciocalteu method. The limit of detection for capsaicin was 0.09 µg.g
−1
.Vitamin C and capsaicin ranged from 95.76 to 2,139 and from 44.40 to 2,224 μg.g
−1
dry matter (DM), respectively. The determined total polyphenol content (TPC) ranged from 4,230 to 9,939 mg GAE.kg
−1
DM and the values of antioxidant activity (AA) determined by using DPPH *, FRAP and ABTS * + methods were in range 19.48-91.81, 19.08-61.46 and 15.72-65.70 μmol TE.g
−1
DM, respectively. Based on the statistical evaluation, there was a high correlation between vitamin C content and antioxidant activity of peppers. The obtained results suggest that due to the composition of bioactive compounds, especially antioxidants, the consumption of pepper fruits is an ideal choice for the prevention of the cell damage.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The influence of the addition of partially defatted milk thistle seed flour was studied by analyzing the rheological properties of dough in order to further exploit the functionality of partially ...defatted milk thistle flour in bakery products. The rheological properties of dough were monitored using Mixolab 2 (Chopin Technologies, France). A rheofermentometer F4 (Chopin Technologies, France) was used to check the dough fermentation, and for the baking trials wheat flour, rye flour, and milk thistle flour were kept in the portion: 50:50:0 (control flour); 50:45:5; 50:40:10 and 50:35:15. The addition of different milk thistle flour in the mixtures resulted in a difference in the viscoelastic properties of the dough. The results showed a weakening of the gluten network in all trial mixtures evaluated. The dough development time values of the control flour were 1.20 min, while an addition of milk thistle flour in portions of 5, 10, and 15% increased these values to 1.30 min, 1.90 min, and 2,80 min, respectively. In addition to higher dough development time values, all trial mixtures exhibited also higher stability (5.07 min; 6.25 min and 8.03 min), when compared to the control flour (4.63 min). The trial mixture with 15% milk thistle flour had different characteristics of gelatinization and retrogradation. The rheofermentometer measured the dough characteristics during proofing, and the trial mixtures with the addition of MTF had a retention volume at approximately the same level as the control flour (WRF). The Volscan profiler was used to determine the bread volume and other parameters. All breads had high volume and specific volume values and can be rated as good, with good porosity and ratio. Mixtures containing 5%, 10% and 15% milk thistle flour added to wheat flour + rye flour maintained rheological parameters within the recommended limits for good technological behavior and, consequently, good quality of bakery products. From all of the above data, it can be stated that, with regard to their baking characteristics, these flour mixtures fall into the category of flours suitable for bakery products.
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.
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.
Bee bread is product with long history used mainly in folk medicine. Nowadays, bee bread is growing in commercial interest due to its high nutritional properties. The objective of this study was to ...determine biological activity of ethanolic extract of bee bread obtained from selected region of Ukraine - Poltava oblast, Kirovohrad oblast, Vinnica oblast, Kyiv oblast, Dnepropetrovsk oblast. The antioxidant activity was measured with the radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical as well as phosphomolybdenum assay. Total polyphenol content was determined with Folin-Ciocalteau reagent and total flavonoid content by aluminium-chloride method. Secondary was also evaluated antimicrobial activity in bee bread samples with disc diffusion method and minimum inhibitory concentrations. Antioxidant activity expressed as mg TEAC per g of dry weight (Trolox equivalent antioxidant capacity) was the highest in bee bread from Poltava oblast in DPPH and also phosphomolybdenum method. Samples of bee bread contained high levels of total polyphenols (12.36 - 18.24 mg GAE - gallic acid equivalent per g of dry weight) and flavonoids (13.56 - 18.24 μg QE - quercetin equivalent per g of dry weight) with the best values of bee bread from Poltava oblast. An elevated level of antioxidant potential in the bee bread determines its biological properties, which conditioned of the biological active substances. The best antibacterial activity of bee bred with disc diffusion method was found against Bacillus thuringiensis CCM 19. The antibacterial activity inhibited by the bee bread extract in the present study indicate that best minimal inhibition concentration was against bacteria Escherichia coli CCM 3988 and Salmonella enterica subs. enterica CCM 3807
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