Extraction and characterization of pectic polysaccharides from Choerospondias axillaris peels: Comparison of hot water and ultrasound-assisted extraction methods

Influences of conventional thermal and innovative non-thermal extraction methods on the physicochemical characteristics and properties of pectic polysaccharides from Choerospondias axillaris peels were investigated. Results showed that ultrasound-assisted extracted polysaccharides (UP) had a heterogeneous nature with lower molecular weight (127.7 kDa) and lower neutral sugar content (35.1%) but higher contents of protein (4.8%) and phenolic compounds (5.1%) than those of polysaccharides extracted by hot water (HP). Additionally, the monosaccharide composition results showed that glucose (77.8%) was the most abundant monosaccharide in HP, while arabinose (67.1%) was the most abundant monosaccharide in UP. The ultrasound significantly induced the degradation of polysaccharide chains but reduced the thermal degradation of phenolics. Finally, we found that UP had higher apparent viscosity, interfacial, emulsifying and antioxidant activity but lower α-glucosidase inhibition activity than those of HP. The results indicated that we could obtain polysaccharides with different functional and biological properties by using different extraction methods.