Extraction characteristics and optimal parameters of anthocyanin from blueberry powder under microwave-assisted extraction conditions

This study investigates the extraction characteristics and optimal parameters of the microwave-assisted extraction of anthocyanin from blueberry powder. Extraction time, extraction temperature, ethanol concentration, and solid-to-liquid ratio were selected as the extraction parameters. The effect of each extraction parameter on anthocyanin extraction rate showed an initially positive and subsequently negative trend, which obeyed the Gaussian equation with convex trend curves. The kinetic constants of extraction time, extraction temperature, ethanol concentration, and solid-to-liquid ratio were 2.44, 58.99, 45.39 and 24.47, respectively. The solid-to-liquid ratio has the most important effect on the anthocyanin extraction kinetic from powdered blueberry, followed by the ethanol concentration and extraction temperature, and the least is the extraction time. The optimum extracting parameters to achieve the highest anthocyanin extraction rate of 73.73% from blueberry powder was obtained under an extraction time of 7 min, extraction temperature of 47 °C, ethanol concentration (v/v) of 55.5%, and solid-to-liquid ratio of 1:34 (g/mL). Three similarity criterions of microwave assisted extraction parameters were developed to extend the criterion magnitudes to the similar conditions.