Optimization of Water Based-extraction Methods for the Preparation of Bioactive-rich Ginger Extract Using Response Surface Methodology
K. D. P. P. Gunathilake
Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada and Department of Food Science and Technology, Faculty of Livestock, Fisheries and Nutrition Wayamba University of Sri Lanka, Makandura, Gonawila, 60170, Sri Lanka
H. P. Vasantha Rupasinghe *
Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada
*Author to whom correspondence should be addressed.
Abstract
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.
Keywords: Ginger, Zingiber officinale, hot water extraction, high pressure homogenization, ultrasonication, polyphenols, LDL oxidation, response surface methodology