The influence of extraction method and conditions on the concentration of flavonoids in the extracts of rowanberries

For the extraction, rowanberries (collected in 2017 and 2018) and aqueous solutions of various concentrations of ethanol (50%, 60%, 70%, 80% and 96%) in a ratio of 1:10 were used. Different types of extraction methods (extraction under static conditions, Soxhlet extraction and ultrasound assisted extraction) were tested. Using different types of extraction methods, it was found that irrespective of the method chosen when the concentration of ethanol increases, the concentration of total flavonoids also increases. Using collected rowanberries in 2017, the highest and similar numerical value of the concentration of total flavonoids was reached when an ultrasound bath was used 20 min for extraction (0.512%) using a magnetic stirrer for 90 min (0.498%). In both cases, a 96% aqueous ethanol solution was used. The highest total concentration of flavonoids in the extracts of rowanberries collected in 2018, obtained under static extraction conditions, using a 96% aqueous ethanol solution, was 0.525%, in 2017 it was 0.418%.