دراسة تأثير الماء و الإيتانول المحمضين بحمض الليمون في استخلاص ملونات و المركبات الفعالة حيوي من نبات الكركدية

Abstract EN

The content of polyphenols, flavonoids, anthocyanins and proanthocyanides were determined.

Along with that ability to inhibit DPPH radical and the ability to reduce iron ions (FRAP) for colored extracts of Hibiscus by axial shaking method and four solvents for extraction were used (distilled water - distilled water acidified with citric acid 2% (w/v)- ethanol 70% acidified with citric acid 1% (w/v) - ethanol 70% acidified with citric acid 2% (w/v)).

The percentages of extracted colourants was calculated.

The highest colorant yield measured for distilled water acidified with citric acid 2%,reaching 66%.

The extract of ethanol 70% acidified with citric acid 2% distinguished having the largest concentration of polyphenols (2021±22.84) mg equivalent gallic acid /100 g dry plant.

The highest concentration of total flavonoids was observed ethanol 70% acidified with citric acid 1% (3178 ±70.80) mg equivalent quercetin /100 g dry plant, No significant differences were observed between anthocyanins concentrations extracted with ethanol 70% acidified with 1% and 2% citric acid, whic were (763.3 ±7.16 , 772.9± 1.239) mg equivalent cyanidin-3-glucoside, 100g of dry plant, respectively.

No significant differences were observed between proanthocyanides concentrations extracted with ethanol 70% acidified with 1% and 2% citric acid, which were (48.71 ± 1.28, 50.45 ± 1.64) mg chlorine cyanidin equivalent / 100 g dry plant, respectively.

Both extracts of ethanol 70% acidified with citric acid 1% and distilled water acidified with citric acid 2% were similar in radical- scavenging activity measured by DPPH test, compared to the FRAP test, which did not show any significant differences when extracting four solvent used.