The study of some quality parameters and the antioxidant activity of dietary supplements with the pomegranate extract (Punica granatum L.)

Abstract

Aim. To conduct a qualitative, quantitative analysis and determine the antioxidant activity of dietary supplements with the pomegranate extract. Materials and methods. Three dietary supplements from different manufacturers – “Extract of pomegranate” (manufactured by Source Naturals), “Extract of pomegranate” (manufactured by Puritan Pride), and “Extract of pomegranate” (manufactured by Vitacost) – were chosen for the study. The thin layer chromatography (TLC) was used to perform the qualitative analysis, the quantity of biologically active substances (BAS) in dietary supplements was determined by the spectrophotometric method, the antioxidant activity – by potentiometric method. The qualitative analysis was performed by thin-layer chromatography (TLC); spectrophotometry was used for the quantitative determination, and the potentiometric method was applied to determine the antioxidant activity. Results and discussions. The presence of anthocyanins, flavonoids, catechins and phenolic acids were detected in the dietary supplements analyzed. The total content of phenolic compounds was 201.00 ± 6.03, 159.00 ± 4.77, 110.30 ± 3.30 mg, catechins was 16.10 ± 0.50, 11.60 ± 0.50, 7.33 ± 0.50 mg, anthocyanins was 43 ± 1.29, 32.00 ± 0.96, 22.00 ± 0.66 mg, and flavonoids was 30.15 ± 0.90, 29.44 ± 1.00, 18.21 ± 0.55 mg. The antioxidant activity was 266.11 ± 5.32, 212.12 ± 4.24, 150.81 ± 3.02 mmol-eqv./mextr for dietary supplements “Extract of pomegranate” (manufactured by Source Naturals), “Extract of pomegranate” (manufactured by Puritan Pride), “Extract of pomegranate” (manufactured by Vitacost) in 1 dosage form, respectively. Conclusions. The analysis of the qualitative composition, the quantitative content of BAS and the antioxidant activity of dietary supplements with the pomegranate extract allows us to find out that dietary supplements manufactured by Source Naturals and Puritans Pride meet the requirements of the State Pharmacopoeia of Ukraine (SPhU), while a dietary supplement manufactured by Vitacost does not correspond the requirements. The results of the study allow us to state that the problem of compliance of dietary supplements is relevant; therefore, it is necessary to introduce normative documentation for the identification and determination of BAS in dietary supplements.