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Effect of microwave-assisted extraction on the release of polyphenols from ginger (Zingiber officinale)

Authors

  • Ismail Rahath Kubra,

    1. Plantation Products Spices and Flavour Technology Department, Central Food Technological Research Institute, Mysore, India
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  • Devender Kumar,

    1. Plantation Products Spices and Flavour Technology Department, Central Food Technological Research Institute, Mysore, India
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  • Lingamallu Jagan Mohan Rao

    Corresponding author
    • Plantation Products Spices and Flavour Technology Department, Central Food Technological Research Institute, Mysore, India
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Summary

The significance of different variables viz. temperature, time and solvent at constant power in microwave-assisted extraction (MAE) process of ginger was studied and compared with conventional method. Aqueous ethanol (50%) provided higher yields of extract as well as the highest release of total polyphenols (TPP) than alcoholic solvents. The reason could be the high dielectric constant of aqueous ethanol as compared to alcohols. Microwave heating being a volumetric process, an exposure time of 1 min was found to be sufficient. The better penetration of microwaves and greater solubility at higher temperature resulted in higher yield of TPP and [6]-gingerol. The resultant extract showed higher radical scavenging activity (RSA) values. Thus, MAE allowed higher recoveries compared to conventional extraction process, with improvement in the quantity and quality of extract in very short period of time.

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