Alena Vollmannová

Degradation of Rutin and Polyphenols during the Preparation of Tartary Buckwheat Bread

The impact of bread making and baking procedure on rutin, quercetin and polyphenol concentration and antioxidant activity of tartary buckwheat (Fagopyrum tataricum) bread and breads made of mixtures of tartary buckwheat and wheat flour was studied. A decrease in polyphenol concentration through baking was observed in all samples. The high DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging capacity in mixed breads (32-56%) and in tartary buckwheat bread (85-90%) decreased slightly through the bread making process, while an increase of antioxidant activity in bread made of 100% wheat flour during bread making was observed. With the addition of water to mixtures containing tartary buckwheat during the preparation of the dough, rutin concentration decreased, while quercetin concentration increased. The rutin concentration continued to decrease during the bread baking process, while the concentration of quercetin remained stable. After baking, rutin (0.47 mg/g) was present only in bread made of 100% tartary buckwheat flour along with quercetin (4.83 mg/g).

Phenolic compounds, antioxidant activity and Cu, Zn, Cd and Pb content in wild and cultivated cranberries and blueberries

The aim of this study was to determine the content of Cu, Zn, Cd and Pb and the total polyphenol (TP) content as well as the total antioxidant capacity (TAC) in wild cranberries and blueberries collected from different localities of the Slovakia and to compare them with properties of six cranberry and six highbush blueberry cultivars obtained from the research centre. Compared with cultivated cranberries (Cu, Zn, Cd and Pb content: 0.642, 1.496, 0.015 and 0.050 mg/kg FM) in wild fruits, higher Cu (by 37%) and lower Zn, Cd and Pb (by 8%, 7% and 44% respectively) were determined using atomic absorption spectrometry method. In wild blueberries, higher Cu, Zn and Pb (by 16%, 209% and 80% respectively) and similar Cd contents were determined compared with cultivated fruits (Cu, Zn, Cd and Pb content: 0.483, 0.541, 0.003 and 0.055 mg/kg FM). The TP contents estimated by spectrophotometry using Folin–Ciocalteau reagent were in intervals 1405–3161 (cranberries) and 1300–3077 (blueberries) expressed as mg GAE/kg FM. While the average TP content determined in wild cranberries was by 31% lower than that in cultivated cranberries, in wild blueberries it was by 97% higher compared with highbush blueberry cultivars. The values of TAC determined by spectrophotometry method using 2,2-diphenyl-1-picrylhydrazyl were in range 20.67–22.22 (cranberries) and 14.03–24.79 (blueberries) expressed as mmol TE/kg FM. In wild cranberries and blueberries, the lower average TAC values compared with cultivated berries were determined (by 1% and 28%, respectively).

Bioactive compounds in different plant parts of various buckwheat (Fagopyrum esculentum Moench.) cultivars

In this study the content of total polyphenolics, rutin, and antioxidant activity in different anatomical parts of common buckwheat plants (Fagopyrum esculentum Moench.) of six cultivars (Spacinska, Emka, Kasho, Jana C1 and Hrusowska) was analyzed. Antioxidant activity in plant material was determined by free radical DPPH. Highest antioxidant activity was assessed in leaves, whereas stems had the lowest antioxidant activity. Total polyphenol content was assessed spectrophotometrically by the Folin-Ciocalteu assay. The highest concentrations were detected in leaves, with values ranging from 68.74 to 90.27 g gallic acid equivalents kg−1, while the lowest concentrations were measured in stems (2.88–3.12 g.kg−1). Significant differences between the anatomical parts were confirmed also for rutin content with the exception of cultivars Kasho and Jana C1, where the rutin content in stem and seeds was not statistically different. The highest concentration of rutin (37.90 g.kg−1) was determined in leaves of cultivar Pyra.

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).

ABSTRACT 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.

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.

MINERALS, TRACE ELEMENTS AND FLAVONOIDS CONTENT IN WHITE AND COLOURED KIDNEY BEAN

The aim of the study was to determine the contents of mineral elements (Ca, K, Mg, N, P), trace elements (Cu, Fe, Mn, Cd, Pb, Ni, Co, Cr, and Zn), and certain phenolic compounds (flavonoids, isoflavones) in the fourteen varieties of cultivated raw kidney beans (Phaseolus vulgaris L.). Heavy metals and mineral elements were analyzed by AAS methods, phenolics were detected by HPLC. Compared with vegetables, legumes proved to be a good source of many minerals and elements, e.g., the contents of K, Mg, P, Fe, and Zn varied in the ranges 13.02 - 23.08 g.kg -1 , 1.41 - 2.52 g.kg -1 , 3.81 - 5.26 g.kg -1 , 0.064 - 0.121 g.kg -1 , and 0.026 - 0.037 g.kg -1 dw, respectively. Kidney beans, both species, contained no or few amounts of phenolics (only four cultivars) and the levels of kaempferol and apigenin were comparable to isoflavone genistein and quite higher than isoflavon daidzein content.

Contamination of potato tubers by heavy metals and their influence on the formation of phenolic substances

increased content of cadmium and lead in soil was manifested by their increased concentration in potato tubers in such range that contents were several times higher (cd 0.106-0.357, Pb 0.318-0.483 mg.kg -1 FM) then the limit value. increased content of zinc was not manifested by increased content in tubers of potatoes (Zn 4.9396.868 mg.kg -1 FM). content of total phenolics (TP) in potato samples of hontiansky and Banskostiavnický region was in the range of 263.59-920.38 mg.kg -1 of dry material. exceeded content of cadmium and lead in potato tubers had statistically significant effect on total phenol producing, but on the other hand relation between contents of Zn and TP in potato tubers was not statistically confirmed. Also positive correlation between TP and antioxidant activity contents was statistically confirmed.

Rheological parameters of dough with inulin addition and its effect on bread quality

The rheological properties of enriched flour prepared with an addition of inulin were studied. The addition of inulin caused changes of the rheological parameters of the recorder curve. 10% and more addition significantly extended development time and on the farinogram were two peaks of consistency, what is a non-standard shape. With increasing addition of inulin resistance to deformation grows and dough is difficult to process, over 15% addition make dough short and unsuitable for making bread. Bread volume, the most important parameter, significantly decreased with inulin addition. Our results suggest a level of 5% inulin to produce a functional bread of high sensory acceptance and a level of 10% inulin produce a bread of satisfactory sensory acceptance. Bread with a level over 10% of inulin was unsatisfactory.

Safety of Potato Consumption in Slovak Region Contaminated by Heavy Metals due to Previous Mining Activity

Heavy metals are among the most serious environmental contaminants in mining districts. Soil, as one of the main components of the environment, is the place of heavy metal entry into plants and consequently into the food chain, too. Potatoes grown in the region of Middle Spis (Slovakia) may be a source of increased content of heavy metals and pose a health risk to the consumer. The contents of heavy metals (Cd, Pb, and Ni) in potato and soil samples were determined using the AAS method and compared with limit values set by the Slovak Republic and the European Union. The content of heavy metals was determined in 12 potato cultivars with different length of vegetation period (mid-early, very early, and early, resp.), which were grown in three localities with a highly disturbed environment. Total contents and mobile forms of heavy metals as well as physical and chemical properties were determined in soil samples which were collected from the same sampling sites. Only Pb content in potato tubers was higher than the hygienic limit value (0.1 mg kg−1 FM) in 15 sampling sites (interval was n.d. –0.2298 mg kg−1 FM). The contents of exchangeable forms (total content) of heavy metals in soil were ranged between the intervals: Cd 0.004–0.055 (0.94–1 56), Pb 0.023–0.295 (17.00–26.80), and Ni 0.019–0.475 (30.80–71.00) mg kg−1. At current average consumption levels of potatoes, tolerable weekly intake (TWI) or tolerable daily intake (TDI) for observed heavy metals was not exceeded.

Effect of the addition of hydrocolloids on the rheological and baking properties of the products with added spelt flour (Triticum spelta L.).

The paper presents the results of the evaluation of the effect of additives on the rheological properties of composite flour made of wheat flour in the amount of 70% and spelt flour at 30%. As additives guar gum (0.5% by weight of flour) and xanthan gum (0.16% by weight of flour) were used. Properties of produced control dough and doughs with hydrocolloids were evaluated by means of rheological appliances by Farinograph, Extenzograph, Amylograph and Rheofermentometer. Based on the observed results it can be concluded that the addition of xanthan gum has a positive effect on increasing of farinographic water absorption capacity, extension of dough development time and dough stability and generally positively affected farinographic properties. The addition of guar gum has improved especially extensographic properties as extensographic energy and extensographic resistance. Based on amylographic evaluation of control doughs and doughs with additives it can be stated that in the dough with guar gum the amylographic maximum has slightly increased. Hydrocolloid guar gum contributed to an increased retention capacity of dough observed. Based on our measurements we can indicate that addition of guar and xanthan gum contributed to an increased rheological quality of doughs prepared with addition of flour from spelt wheat. With reference to the baking experiment it was found that the use of hydrocolloids has a positive effect on the improvement of the baking properties, in particular larger volume, specific volume, and the volume yield of the dough with the addition of guar and xanthan gum compared to the control. Our results showed that aditives significantly influenced rheological qualities of dough and a baking quality of products. These findings thus allow optimizing the recipe in order to increase the technological quality of leavened bakery products.