Cinética de la extracción sólido-líquido de antocianinas obtenidas a partir de Hibiscus rosa-sinensis

Abstract

In this study the effect of temperature (25, 40 and 60 °C), solvent polarity using water (H2O)-ethanol (EtaOH) solvent with 100, 90:10 and 80:20 (H2O:EtaOH % v/v), and solvent-to-solid ratio (40/1, 60/1 and 80/1 mL/g) on the extraction yield of anthocyanins from Hibiscus rosa-sinensis was analyzed. The experimental data were fitted to Spiro and Siddique model with a good accuracy () and the specific extraction rate constant was perfectly related to the apparent diffusivity using the lumped parameter model. The major percentage of the anthocyanin extraction yield was 63.81±1.33, 68.95 ±1.53, and 83.09±3.14 when the used solvent was H2O, H2O-EtaOH (90:10), and H2O-EtaOH (80:20), respectively.  The diffusivity was affected mainly by temperature, tending to be more temperature sensitive as the solvent polarity decreased. Activation energy values (), in range from 19.64 to 29.28 kJ mol-1, allow to infer that the extraction of anthocyanins is favored when using an ethanolic aqueous solution as a solvent. Response surface methodology was successfully applied to the anthocyanin extraction yield, confirming that the process parameters (solvent polarity, solid-to-solvent ratio and temperature) affected the extraction yields.