A novel extraction method for β-carotene and other carotenoids in fruit juices using air-assisted, low-density solvent-based liquid-liquid microextraction and solidified floating organic droplets

Green extraction using air-assisted, low-density solvent-based liquid-liquid microextraction and solidified floating organic droplets (AA-LDS-LLME-SFOD) prior to spectrophotometry was successfully applied for quantitation of carotenoids in fruit juices. Under optimal conditions, beta-carotene could be quantified with a linear response up to a concentration of 60 mu g mL (1). The procedure was performed in a microcentrifuge tube with 40 mu L of 1-dodecanol as the extraction solvent and a 1.0 mL juice sample containing 8% NaCl under seven extraction cycles of air pumping by syringe. This method was validated based on linearity (0.2-30 mu gmL (1), R-2 0.998), limit of detection (0.04 mu gmL (1)) and limit of quantification (0.13 mu gmL (1)). The precision, expressed as the relative standard deviation (RSD) of the calibration curve slope (n = 12), for inter-day and intra-day analysis was 4.85% and 7.92%, respectively. Recovery of beta-carotene was in the range of 93.6-101.5%. The newly proposed method is simple, rapid and environmentally friendly, particularly as a useful screening test for food analysis. (C) 2016 Elsevier Ltd. All rights reserved.