Antioxidant Activity and Total Phenolic Content of Capsicum frutescens Extracted by Supercritical CO₂, Ultrasound and Traditional Solvent Extraction Methods

Abstract

In this study, Capsicum frutescens was extracted by supercritical CO₂, ultrasound assisted and traditional solvent (ethanol, water and ethanol: water (50:50)) extraction methods. The antioxidant activity of the extracts was assessed and comparison with TBHQ by DPPH and β-carotene bleaching methods was done. Moreover, efficacy of C. frutescens extracts in stabilizing soybean oil during accelerated storage was studied. The results show that the extract form ethanol: water (50:50) ultrasonic treatment had the highest amount of phenols (810 mg gallic acid/ gr extract, tocopherols (233.01 μg α-tocopherol/mL extract) and antocyanin content (331.59 μg/mL extract) caused to evaluate its highest antioxidant activity (65.97% radical scavenging and 49.6% β-carotene-linoleic bleaching) and thermal stability (4.68 h) at 120°C in soybean oil. However, the supercritical carbon dioxide extraction method as a safe extraction method also preserved the phenolic, tocopherol and antocyanin content of C. frutescens extract (705.9 mg gallic acid/ gr extract, 299.29 μg α-tocopherol/ mL extract and 300.66 μg/ mL extract, respectively). And can remarkably protect the oil from lipid oxidation (OSI, 4.50 h). Results of different extraction methods can strongly reveal the C. frutescens extracts has remarkable potential for stabilization of edible oils.

Key words:

• Antioxidant activity
• Capsicum frutescens
• Phenolic content
• Thermal stability