ANTIOXIDANT PROPERTIES OF SELECTED LESS COMMON FRUIT SPECIES

The aim of this study was to determine the anthocyanins, ascorbic acid content and the antiradical activity in less common fruit species native in the territory of Slovakia (black mulberries, cornelian cherries, blackberries, blackthorn, rowanberries) and honeyberries (Lonicera kamtschatica) originated from Kamtschatka. Anthocyanins were evaluated after extraction from solid materials with acidified ethanol or after direct solution of liquid samples with HCl in ethanol solution by spectrophotometer measurement. To evaluate the antiradical activity, a spectrophotometer method based on the reaction of antioxidants with a stable radical 2,2- diphenyl- 1- picrylhydrazyle (DPPH•) in methanol solution was used. The reduction properties of ascorbic acid are used in the measurement. The highest value of anthocyanin pigments was found out in honeyberries (Lonicera kamtschatica) of all analyzed clones. Black mulberries of the genotype M104 and cornelian cherries of the genotypes 55 a 44 are the most significant sources of ascorbic acid among analysed less common fruit species. It is an interesting fact that blackthorns (Prunus spinosa) contenting the lowest value of ascorbic acid (10.31±1.016 mg.100 g-1) and medium value of anthocyanins (1.71±0.08 g.kg-1) shows the highest level of antiradical activity (461.25±3.69 % ≈ EC50= 0.1084 ± 0.0101). A similar phenomenon was observed in honeysuckles, too. According to these results we can suppose that another flavonoids (flavonols, flavons and flavanols) can also significantly contributed to antiradical activity of the blackthorns and edible honeysuckles. In summary, analysed less known fruit species are important sources of nutritive compounds, particularly anthocyanins, ascorbic acid and show significant free radical scavenging ability.