Optimization conditions for the extraction of anthocyanins from the hibiscus flower calyxes (Hibiscus sabdariffa L.)

Abstract

Due to their high content of anthocyanins, the extracts of Jamaican calyxes represent a potential alternative for the replacement of synthetic dyes in the food industry. The objective of the study was to determine the optimal conditions for the extraction of anthocyanins from the hibiscus flower calyxes through a factorial design of the Box-Behnken type with two factors and three levels, considering as independent variables the mass-solvent ratio (1/10 at 1/20 m/v) and alcohol concentration (30 to 60% v/v) and as a response variable the total mass of anthocyanin extracted. It was determined that the optimal numerical solution for the extraction conditions was 42% ethanol and the mass-solvent ratio equal to 1/20 m/v, which corresponds to a predicted value of 48 mg of extracted anthocyanins. The validity of the optimization was confirmed by performing three extractions under the aforementioned conditions and it was determined that the alcohol concentration significantly influenced the extraction process.