Abstract:

The influence of different extraction methods, including conventional water extraction, ultrasound-assisted
water extraction, and microwave-assisted water extraction, on chemical composition and antioxidant activity of crude
polysaccharides extracted from pumpkin peel (CPPPs) was investigated. The results showed that the extraction yield of
CPPPs was significantly affected by extraction method and the highest extraction yield (4.52%) of CPPPs was obtaiend with
microwave-assisted water extraction. It was found that the monosaccharide composition and molecular size distribution
of CPPPs were also significantly affected by extraction method. The DPPH radical scavenging activity of CPPPs from
conventional water extraction, ultrasound-assisted water extraction, and microwave-assisted water extraction presented IC50
values of 0.18, 0.27 mg/mL, and 0.24 mg/mL, respectively. Therefore, CPPPs obtained by conventional water extraction
possessed much higher DPPH radical scavenging activity than those obtained by the two other methods.

Key words: pumpkin peel, crude polysaccharides, extraction methods, composition, antioxidant activity