Ultrasound-Assisted Extraction, Preliminary Characterization, and Antioxidant Activity of a Novel Water-Soluble Polysaccharide from Lotus (Nelumbo nucifera Gaertn.) Seeds

Abstract

Ultrasound-assisted extraction was employed to extract polysaccharides from lotus (Nelumbo nucifera Gaertn.) seeds. Response Surface Methodology was used to determine the optimal extraction conditions of ultrasound power, extraction time, and extraction temperature at 406 W, 7.7 min, and 94°C, respectively. The crude extract was successively purified by chromatography, yielding a major polysaccharide fraction termed LSPS-1. It is a heteropolysaccharide, containing rhamnose, arabinose, glucose, and galactose with a molecular weight of 4484 Da and an α-dominating configuration in pyranose form sugar. Preliminary antioxidant activity test in vitro showed LSPS-1 could potentialize the scavenging effect on hydroxyl radicals in a dose dependent manner.

Keywords:

• antioxidant activities
• characterization
• extraction
• lotus seeds
• polysaccharide

ACKNOWLEDGEMENTS

The research was financially supported by the China State “11th Five-Year Plan” scientific and technological support scheme (2007BAD07B05), the Special Major Science and Technology Project in Fujian Province (2008N0007), the Natural Science Fund in Fujian Province (2006J0190, 2011J05123), Program for Scientific and Technological Innovation Team of FAFU (CXTD12009), and the Spark Program of Fujian Province (2012S0044).

Notes

^a SS, Sum of squares.

^b DF, Degree of freedom.

^c MS, Mean square.

^a Not detected.