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PL
Celem przeprowadzonych badań była ocena możliwości wykorzystania kory brzozy brodawkowatej (Betula pendula Roth) w biomonitoringu terenów leśnych. Do badań wykorzystano korę drzew rosnących na obszarze Beskidów i Puszczy Boreckiej. W korze, metodą absorpcyjnej spektrometrii atomowej ze wzbudzeniem w płomieniu (F-AAS), oznaczono stężenia metali ciężkich: Mn, Fe, Ni, Cu, Zn, Cd oraz Pb. Na podstawie przeprowadzonych badań stwierdzono sezonowe zmiany stężenia analitów. Wykazano również, że kora brzozy brodawkowatej może być wykorzystywana jako bioindykator do oceny zanieczyszczenia aerozolu atmosferycznego na tych obszarach np. metalami ciężkimi. Ważne jest jednak, aby dokonać walidacji poszczególnych etapów procedury analitycznej z wykorzystaniem kory drzewa oraz uwzględnić czas pobierania materiału do badań.
EN
The aim of the study was to assess the possibility of using silver birch bark (Betula pendula Roth) in biomonitoring of forest areas. The research involved the use of tree bark growing in two areas - the Beskidy and the Borecka Forest. In the bark, by the method of atomic absorption spectrometry with flame excitation (F-AAS), concentrations of heavy metals: Mn, Fe, Ni, Cu, Zn, Cd and Pb were determined. On the basis of the conducted study, there were determined seasonal changes in the concentration of analytes. It was shown that the bark of a silver birch can be used as a bioindicator to assess atmospheric aerosol contamination in these areas, e.g. with heavy metals. It is important to validate the individual stages of the analytical procedure using the tree bark and take into account the time of collecting the material for testing.
2
Content available Antioxidative capacity of birch saps
EN
In our subsequent studies of birch tree saps we focused on assessing their antioxidant capacity. For research we chose four groups of silver birch trees (Betula pendula Roth.), consisting of five individuals. Antioxidant capacity was examined using spectrophotometric technique. The highest antioxidant capacity, tested by the Folin-Ciocalteau method and expressed as a total phenolics content was 6.59 mg GAE/100 ml of tree sap, and in turn the lowest one 0.88 mg GAE/100 ml. The highest antioxidant capacity determined ABTS method and expressed as radical scavenging activity (RSA) was 30.9% and lowest 5.38% The average values of antioxidant capacity both expressed as a phenolic compounds content and as radical scavenging activity for tree saps collected from four particular locations did not differ significantly. Based on the obtained results of tree sap analyses, it can be claimed that compared to other food products, e.g. fruit and vegetable juices, birch saps are not a rich source of phenolic compounds and when compared e.g. to tee infusions, they have low antioxidant capacity. Although it can be increased by the introduction of functional additives, such as herbal extracts or concentrated fruit juices.
3
Content available remote Badania trwałości soków drzewnych brzozowych
PL
Popularność soków brzozowych wzrasta, a szereg źródeł wskazuje na liczne korzyści zdrowotne wynikające z ich spożywania. Rzadko jednak zwraca się uwagę na niską trwałość soków brzozowych, a badania naukowe dotyczące tego zagadnienia są nieliczne. W niniejszej pracy podjęto próbę oceny trwałość pięciu partii soku brzozowego, które były przechowywane w temperaturze pokojowej oraz w warunkach chłodniczych. Parametrem najkorzystniejszym do oceny zmian zachodzących w soku brzozowym okazała się mętność, w mniejszym zaś stopniu – tzw. „gęstość optyczna” i odczyn. Na podstawie pomiarów tych wartości stwierdzono, że sok brzozowy w temperaturze pokojowej może być przechowywane nie dłużej jak 1 dzień, natomiast w warunkach chłodniczych około 6 dni.
EN
Birch tree sap popularity is increasing and a number of sources point to the numerous health benefits of their consumption. Rarely, however, attention is drawn to the short shelf life of birch tree sap and there are few researches on this subject. In this paper, shelf life of five batches of birch tree sap was evaluated. They were stored at room temperature and in refrigeration. Most favorable parameter for the assessment of changes in birch sap was its turbidity, and to a lesser degree the so-called “optical density” and pH. On the basis of the obtained results, it was found that birch sap at room temperature can be stored for no longer than one day, while in refrigeration of about six days.
4
Content available remote Turbidity changes of birch tree sap after addition of commonly available chemicals
EN
The problem signalled both by the popularizers of birch tree sap consumption, as well as in many scientific articles and sap collection manuals is short shelf life, hindering the wider use. The loss of shelf life is manifested by the appearance of a characteristic turbidity and simultaneously intensifying unpleasant odor. Most of birch sap shelf life extension methods, that inhibit turbidity, are non-thermal methods, based on the physical techniques, ex. ultraviolet radiation, ultrafiltration, and also combination of this two methods. The aim of this study was to assess the stability of the birch tree sap, depending on the concentration of commonly available chemicals used to extend shelf life of plant origin food products. At room temperature, the sample with addition of ethanol at the concentrations of 10% and 15%, as well as with the addition of citric acid in combination with potassium sorbate were stable during the all turbidity testing period. Additionally, in the refrigerated condition, 27-day stability has been obtained for the sap with the addition of ethanol at the concentration of 5% and 15-day with the addition of citric acid in concentration of 0,5%. This stable solutions obtained, however, are not suitable for direct consumption. They can only be used as a stable base for the preparation of beverages, after the addition ex. herbal extracts, fruit juices and syrups, honey.
5
Content available remote The usefulness of birch saps from the area of Podkarpacie to produce birch syrup
EN
In northern European countries, as well as in North America tree saps of maples and birches are used for the production of syrups. Birch syrups are characterized by a specific aromatic taste and can be used as an addition to sweets, desserts, salads and meats. Attention is paid to the health benefits of birch syrups, mainly for high mineral content. The aim of this study was to evaluate the usefulness of birch saps obtained from the area of Podkarpacie for birch syrup production. HPLC-ELSD system was used for analysing the sugar content in the birch tree saps from four localization. All the examined saps contained the monosaccharides as fructose and glucose. The presence of sucrose was found in eight per twenty tested saps. There weren’t statistical differences between the studied sites for the averages of total sugar concentration in the tree saps samples. The highest average amount of total sugar was found in the D sites (11.74 g/dm3), whereas the lowest in the C sites (7.66 g/dm3). Silver birch tree saps from the area of Podkarpacie offer perspectives to used for syrup production according to the US and Finnish criteria of profitability.
EN
The variability of selected ratios characterising the dimensions and shape of silver birch wood fibres was determined based on the site where the trees grow. Two sampling areas were selected, located in the Biała Podlaska Forest District in eastern Poland. Samples for testing were taken from trees approx. 45–50 years old, growing on a fresh broadleaved forest site and on a fresh mixed broadleaved forest site. On these two sites, silver birch occurs most widely as a dominant species, both in terms of stand area and volume, in Poland. A statistical analysis was performed of selected parameters of the wood fibre structure such as length, width, lumen and cell wall thickness, as well as of the wood fibre structure ratios belonging to the basic properties of fibrous pulp: the felting power, flexibility ratio, coefficient of rigidity, Runkel and Mühlsteph ratios, as well as the compactness index. It was demonstrated that the site from which birch material originates has a significant impact on the average values of: fibre length, lumen, flexibility ratio, and the coefficient of rigidity, as well as the Runkel and Mühlsteph ratios. However, analyses did not prove any major impact of the site on the average values of: fibre width and wall thickness, the felting power or the compactness index of silver birch wood.
EN
The paper analyses the production and allocation of biomass in young, spontaneous silver birch afforestation occurring on post-agricultural lands in the Mazowsze region (central Poland). We investigated 114 sample plots of age varying from 1 to 19 years. During the first 15 years after their establishment on abandoned farmland, the naturally regenerated silver birch stands produced on average approximately 75 tons of dry biomass per hectare. The major (50–70%) part of this biomass was stored in the tree stems and this share increased with age. The fractions of biomass in the foliage and roots decreased over time, while the share of biomass in the branches remained rather constant. The significant age-dependency of the allometric relationships suggested the need to use age-sensitive biomass expansion factors to estimate the biomass from the stem volume.
EN
Research on the effect of birch regeneration on changes occurring in the environment on former farmlands included a quantitative and qualitative analysis of the biomass growing on the research plots. Five experimental plots were selected in the Mazovia region: two in Dobieszyn and the Kampinos National Park and one in Kozienice. The analysis performed on each plot was concerned with the amount and chemical composition of biomass in four patches of vegetation, characterised by the different ages of the birch trees growing there. The vegetation patches were classified according to age group, i.e. I: 1–4 years old, II: 5–8 years old, III: 9–12 years old and IV: over 12 years old. Biomass samples were collected in the field and determined in kg DM/ha using the following components: roots, stem, bark, branches, assimilation apparatus, litterfall and the total biomass of the other (except birch) plants. For all the above-mentioned groups, the content of the elements N, C, S, Ca, K, Mg, Na, P, Mn, Cu, Fe, Zn, Pb, and Cd was determined. This allowed us to obtain both the values of the concentrations of particular substances and their allocation in both the organic matter and litterfall. The aim of the research was to discover whether the allocation of elements changes with the age of birch growing on former farmland.
EN
The process of soil degradation and destabilization of forest ecosystem by industrial pollution is frequently associated with mobilization of toxic. Al^3+ ions. Both these processes exert a negative influence on tree root systems and may even result in the decline of whole forest stands. One-year-old seedlings of silver birch (Betula pendula Roth.) grown in pots were treated with a range of aluminum sulfate concentrations in order to test the effects of Al on growth, root structure, content of phenolic compounds and mineral nutrition of roots and foliage. Plants exposed to Al concentrations exceeding 50 mg Al dm^-3 had reduced growth, root structure and a substantial increase of Al concentration occurred in foliafe and roots. Concentration of several elements in the foliage and roots declined with increasing Al concentration, including Mg and Ca , and to a lesser extent, P, K, and Na. Most root traits such as root mass or root growth rate were more strongly affected by Al than the foliage. Changes in root Ca, Al and Ca:Al ratio, and root morphology were detected at the lowest Al concentration (50 mg Al dm^-3) indicating usefulness of these traits as early indicators of adverse aluminum effects on plants.
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