Extraction and analysis of the major carotenoids of agro-industrial waste materials using sequential extraction techniques and high performance liquid chromatography

Abstract

The objective of the present study was to develop sequential extraction procedures for the major carotenoids - beta-carotene and lycopene from agro-industrial waste materials - tomato skin, tangerine and orange peels using the ultrasound-assisted extraction and the supercritical fluid extraction techniques. A rapid, effective and selective high performance liquid chromatographic method for quantitative determination of beta-carotene and lycopene in organic extracts solutions was developed and validated with respect to robustness, specificity, linearity-range, accuracy, precision, limit of detection (LOD) and quantitation (LOQ) as well. The effect of the operating pressure, the temperature, the extraction time, the flow rate of supercritical fluid, the sample size, the ultrasound power and the solvent nature used was investigated. The optimal conditions for extraction were found. The LOD and the LOQ are 0.0081μg/mL and 0.00405 μg/mL for beta-carotene, 0.034 μg/mL and 0.0085 μg/mL for lycopene, respectively. No interference was observed. The content of beta-carotene per 1 g of dried agro-industrial waste material varies 8.39-12.75 μg (tomato skin), 25.65-32.18 μg (tangerine peel), 41.66-59.16 μg (orange peel) and the content of lycopene - 165.11-179.56 μg (tomato skin), 11.12-17.91 μg (tangerine peel), 8.37-10.65 μg (orange peel).