Antioxidant activity of polysaccharide extracted from Ganoderma lucidum using response surface methodology

Area of Science:

• Food Science
• Biochemistry
• Natural Product Chemistry

Background:

• Ganoderma lucidum (reishi mushroom) is recognized for its medicinal properties.
• Polysaccharides from G. lucidum have demonstrated various bioactivities.
• Efficient extraction methods are crucial for isolating bioactive compounds.

Purpose of the Study:

• To optimize the extraction of Ganoderma lucidum polysaccharides (GLP) using superfine grinding and response surface methodology (RSM).
• To characterize the extracted polysaccharides and evaluate their antioxidant activities.
• To explore the potential of G. lucidum as a source of natural antioxidants for the food industry.

Main Methods:

• Superfine grinding technology for enhanced polysaccharide extraction.
• Response surface methodology (RSM) to optimize extraction parameters (time, temperature, water-to-material ratio).
• High-performance liquid chromatography (HPLC) and Fourier-transform infrared spectroscopy (FT-IR) for polysaccharide characterization.
• Assays for reducing power, DPPH radical scavenging, and oxygen radical scavenging ability to evaluate antioxidant activity.

Main Results:

• Optimal extraction conditions determined: 137 min, 66°C, 35 mL/g water-to-material ratio, yielding 2.44% GLP.
• GLP were fractionated into GLP40, GLP60, and GLP80.
• HPLC analysis revealed distinct monosaccharide compositions for GLP and its fractions.
• FT-IR confirmed a β-pyranoid ring structure for all analyzed polysaccharides.
• GLP80 exhibited the highest antioxidant activity, followed by GLP, GLP60, and GLP40.

Conclusions:

• RSM is an effective technique for optimizing GLP extraction efficiency.
• Ganoderma lucidum is a valuable source of natural antioxidants.
• Extracted polysaccharides, particularly GLP80, show significant potential as food antioxidants and preservatives.