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Antioxidative capacity of birch saps

Bilek M., Siembida A., Gostkowski M., Stawarczyk K., Cieślik E.

Biotechnology and Food Science

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2017

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Vol. 81, nr 1

3--10

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.

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Turbidity changes of birch tree sap after addition of commonly available chemicals

Bilek M., Sądej M., Rączy M., Rębisz A., Sosnowski S.

Biotechnology and Food Science

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2016

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Vol. 80, nr 2

83--90

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.

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The usefulness of birch saps from the area of Podkarpacie to produce birch syrup

Bilek M., Olszewski M., Gostkowski M., Cieślik E.

Biotechnology and Food Science

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2016

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Vol. 80, nr 1

11--18

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.