Efficiency of ultrasound assisted extract of Delonix regia petals as natural antioxidant on the oxidative stability of sunflower oil

Abstract

The possibility of improving the oxidative stability of sunflower oil by enriching it with carotenoids from Delonix regia petals was studied. A combination of ultrasound-assisted extraction and stirring techniques was used. The optimal conditions were material/solvent ratio of 1:20 (w/v), ultrasonic power of 30 W and extraction time of 50 min. Under these conditions, the yield of total carotenoids was 503.0 μg/g dry weight. Increasing the acoustic power density degraded carotenoids. A HPLC analysis was used for the quantification of β-carotene in the extract. The DPPH radical scavenging activity and ferric reducing antioxidant power of the carotenoid-rich extract were found to be superior to the standard Butylated hydroxyl toluene (BHT). The enrichment of sunflower oil with carotenoid-rich extract at 67.46 mg carotenoids/kg oil improved its oxidative stability by more than 50% as measured by the Rancimat method. These results suggest that the investigated extract has the potential to be used as a bio-preservative in food products.