Quantitative analysis of quercetin in malpighia emarginata dried extract by hplc-dad

Acerola (Malpighia emarginata) is widely distributed in Brazil and has a large amount of flavonoids. Quercetin is a flavonoid present in this fruit and its protection is necessary due to its high antioxidant activity. Thus, encapsulation by spray drying is the most used technique for the protection of this compound. Furthermore, it is necessary to determine the biomarkers contained in the dry extract of acerola. In a sample of dry extract of acerola, a selective extraction was carried out for quercetin determination by chromatographic analysis. In HPLC-DAD the mobile phase was a 0.2% methanol and phosphoric acid solution (65:35). The flow rate was 1.0 ml min-1 at 30°C. and detection at 360 nm. The linear range of quercetin was 0.025–0.150 mg.ml-1 (r2 = 0.9980) with a recovery rate of 97.50 - 103.30% (average 100.40%; RSD 2.28%). Separation of the baseline target component occurred within 4 min. An RSD repeatability of 1% was performed and the highest quercetin content in the dry extract was (average 0.025 mg g-1). It was concluded that HPLC-DAD was sufficient for the determination of quercetin in the microencapsulated dry extract of Acerola and that the selective extraction was determinant for the quantification of this biomarker.