OPTIMIZATION OF ULTRASOUND-ASSISTED EXTRACTION OF NATURAL COLORANT FROM HUYET DU LEAVES USING ETHANOL SOLVENT

Abstract

In this paper, the natural colorant from Vietnam Huyet du leaves were extracted by ultrasound-assisted extraction (UAE) technology using ethanol solutions. Three independent variables including extraction temperature (30-70 °C), ethanol concentration (5-95%) and sonication time (5-45 min) were investigated. The Box-Behnken design (BBD) with the help of Design Expert 10 was used to investigate the effect of process variables on the Huyet du colorant
extraction process. Second-order mathematical regression model was developed and matched well with observed data. Response surface methodology (RSM) was performed to find out the optimal condition for total anthocyanin content as follow: extraction temperature of 69.85°C,
ethanol concentration of 94.15% and sonication time of 30.49 min. In this optimal condition, the total anthocyanin content was determined as 46.43 mg/l extract. The experimental value under optimal condition was in good consistent with the predicted value. In addition, the UV/Vis and FTIR analyses were confirmed that anthocyanin compounds are the major colouring components
of Huyet du extract. A rotary evaporator was employed for concentrating Huyet du anthocyanin solution and recovering ethanol solvent.