Optimization of Water Based-extraction Methods for the Preparation of Bioactive-rich Ginger Extract Using Response Surface Methodology

Aims: Evaluation of three extraction methods to prepare bioactive-rich ginger extract for incorporation into a functional beverage.

Study Design: Response surface methodology.

Methodology: For the preparation of bioactive-rich ginger extract with water, conventional hot water extraction, ultrasonic-assisted extraction and high pressure homogenization-assisted extraction were evaluated. Response surface methodology was employed to optimize the extraction conditions of each method with respect to the highest polyphenols, antioxidant capacity (ferric reducing antioxidant power; FRAP) and percent inhibition of low density lipoprotein (LDL) cholesterol oxidation.

Results: Multiple response optimizations revealed that the optimum extraction conditions for each extraction method were 60min extraction time under 55°C for hot water extraction, 15min ultrasonication under 52°C for ultrasonic-assisted extraction and 62°C under 140MPa homogenization pressure for high pressure homogenization-assisted extraction.

Conclusion: The extract prepared from the ultrasonic-assisted extraction method exhibited the highest polyphenol recovery and antioxidant activity, compared to the extracts prepared from other two methods.