Tree saps were once commonly used in the countries of Northern, Central and Eastern Europe. Although once almost forgotten, their popularity has been growing recently as part of an interest in organic food and traditional medicine. Tree saps, tapped mainly from birch and maple trees, are drunk both fresh and fermented or are used as raw material for the production of food products, e.g. syrups. The aim of this study was to determine the content of inorganic anions in tree saps, as this parameter is often associated with toxicity of plant products. We measured the content of chlorides, nitrates and sulphates in the saps of six tree species with high pressure ion chromatography with the conductometric detection method. We detected the presence of chlorides, nitrates and sulphates in the studied tree saps. The highest concentration of nitrates was in the saps tapped from Norway maple (65.578 mg dm-3) and boxelder (108.313 mg dm-3). On the other hand, the highest concentration of sulphates was detected in the white willow tree saps (112.512 and 35.389 mg dm-3), while the one of chlorides, in the hornbeam tree sap (47.257 mg dm-3) and the Norway maple tree sap (41.143 mg dm-3). The detected content of chlorides, sulphates and nitrates in the tree saps under study does not reach toxic levels. Therefore we conclude that tree saps do not pose any health threat to consumers regarding their content of inorganic ions. Additionally, we observed a high intra- and interspecies variability in the concentration of inorganic anions in saps. This observation should be taken into account while designing any quality monitoring protocol regarding tree saps.

22.4.2016