Abstract:

The aim of the work was to develop a spectrophotometric method of flavonoids determination in bilberries shoots. Materials and Methods. The samples of bilberries shoots, collected in Transcarpathian, Ivano-Frankivsk, Ternopil and Volyn regions in 2014-2018, as well as the samples of the drug Shoots of Bilberries (PJSC Liktravy, Ukraine) were used in the study. The determination of flavonoids content was carried out by absorption spectrometry, measuring the absorption of flavonoids complex with aluminum chloride. The spectrophotometer Cary 50 UV-Vis (Agilent Technologies) was used to measure the absorption and record the electronic absorption spectra. Results and Discussion. Electronic absorption spectra, which were obtained for the test solutions and the standard rutin solution in the conditions of complexation of flavonoids with aluminum chloride, were identical in the course of light absorption curves and were characterized by absorption maximum at 410±2 nm and 412±2 nm respectively that made it possible to make rutin a standard for recalculation of flavonoids content in the investigated plant raw material. When investigating the ethanol concentration effect on flavonoids extraction, it has been established that 70% (v / v) of ethanol should be used to prepare the sample solution. The flavonoids removal for an analytical purpose should be performed by heating under a reflux condenser three times – alternately together with 60, 20 and 15 ml of ethanol for 30, 15 and 15 minutes, respectively. An important aspect of the technique is the preparation of raw materials: a fraction (355) of crushed raw material should be used for analysis, given its content in the calculation formula. It has been established that the flavonoids content in the studied wild samples is within the range of 1.14-1.86%, and in the industrial series (except of raw materials of the series 20614) – 0.7-1.0%. Conclusions. The spectrophotometric method of flavonoids quantitative determination in the bilberries (Vaccinium myrtillus L.) shoots was developed. Quantitative determination of the flavonoids content in 17 samples of raw materials of different origin was carried out as well. To evaluate the bilberry shoots quality, it was suggested to introduce an additional index ‘flavonoids content’ with a criterion – not less than 0,6% of flavonoids equivalent to rutin and dry raw material.

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