Characterization and antioxidant activity of polysaccharides obtained from ginger pomace using two different...

Area of Science:

• Food Science
• Biochemistry
• Natural Product Chemistry

Background:

• Ginger pomace is a byproduct of ginger processing.
• Polysaccharides are known for their diverse biological activities, including antioxidant properties.
• Efficient extraction methods are crucial for utilizing bioactive compounds from agricultural waste.

Purpose of the Study:

• To compare hot water (HW) and ultrasonic-assisted (UA) extraction of polysaccharides from ginger pomace (GPPs).
• To characterize the structural properties of extracted GPPs.
• To evaluate the in vitro antioxidant activities of GPPs obtained by different methods.

Main Methods:

• Extraction of GPPs using optimized hot water and ultrasonic-assisted methods.
• Characterization of GPPs including molecular weight, sugar and protein content, uronic acid, monosaccharide composition, and sulfuric radical content.
• In vitro antioxidant assays (DPPH, hydroxyl, and superoxide radical scavenging).

Main Results:

• Ultrasonic-assisted extraction yielded higher amounts of GPPs compared to hot water extraction.
• GPPs extracted by UA showed significantly better scavenging abilities against DPPH, hydroxyl, and superoxide radicals than those extracted by HW.
• Structural analysis revealed differences in molecular weight distribution and certain chemical compositions between HW-GPPs and UA-GPPs, though monosaccharide compositions were similar.

Conclusions:

• Ultrasonic-assisted extraction is a more effective method for obtaining polysaccharides with higher yields and enhanced antioxidant bioactivity from ginger pomace.
• UA-GPPs demonstrate potential as natural antioxidants.
• Ginger pomace can be considered a valuable source for the development of natural antioxidants.