Certain phenolics and cyanogenic glycosides in various fruit species and plant parts were analyzed and measured using HPLC-MS-technique in six different experiments. The main part focused on the seeds of some pits and kernels of the Rosaceae family that can be used in daily nutrition. The contents varied greatly between the different fruit species studied and their cultivars. The seeds of the fruits contained 2- to 46-times higher contents of cyanogenic glycosides than phenolics. Beside the seeds, we were also interested in analyses of differences in their contents among leaves, flowers and berries of different Sambucus species growing in Europe. Compared to black and red elderberry, dwarf elder contains the highest contents of phenolics and and low contents of cyanogenic glycosides. Furthermore, we were interested in how some environmental factors, such as location, altitude and climate influence the contents of the studied compounds. We found that both, the content of cyanogenic glycosides and phenolics reacted strongly to external environmental factors and their content increased with increasing exposure of the plant to stress factors. Thus, fruits collected at higher altitudes with more negative environmental conditions (lower temperature, higher solar irradiation) contained the highest contents of the studied compounds, specifically cyanogenic glycosides, as well as phenolics, especially anthocyanins. Different methods of fruit processing into various fruit products are of dominant importance. Additionally, we investigated the influence of storage and fruit processing on the content of potentially beneficial phenolics and potentially harmful cyanogenic glycosides. The analyzed substances changed in the fruit after harvest and were transferred from the fruit to the final products after the different processing techniques, where they were preserved. Most of the analyzed phenolics, with the exception of hydroxycinnamic acids, were more soluble in organic solvents than in water. The phenolic contents increased with the duration of extraction process, while the cyanogenic glycosides decreased. By heating and mechanical treatment of the plant material, the content of phenolics, especially anthocyanins, and cyanogenic glycosides was considerably reduced.
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