Physicochemical properties and antioxidant activity of polysaccharides obtained from sea cucumber gonads via ultrasound-assisted enzymatic techniques

The physicochemical properties and antioxidant activity of sea cucumber gonadal polysaccharide extracted by enzymatic, ultrasound and ultrasound-assisted enzymatic methods were investigated. The results showed that the total sugar and sulphate group content (69.1 g/100 g, 14.7 g/100 g) of SCGP-UAE were higher than those of SCGP-E (58.8 g/100 g, 10.6 g/100 g) and SCGP-U (62.9 g/100 g, 13.3 g/100 g). The zeta potential, molecular weight and particle size of SCGP-UAE were significantly lower than those of SCGP-E and SCGP-U (P < 0.05). Their molar ratios of monosaccharide composition were different. With the concentration of SCGP-E, SCGP-U and SCGP-UAE from 0.25 increased to 4.00 mg/mL, the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH center dot), hydroxyl radical (center dot OH) scavenging ability and reducing power of them were improved. In the concentration range of 0.50-4.00 mg/mL, the antioxidant ability of SCGP-UAE was higher than SCGP-E and SCGP-U. At 4.00 mg/mL, the DPPH center dot, center dot OH scavenging ability and reducing power of SCGP-UAE were 12.8%, 14.6% and 9.42% higher than those of SCGP-U and 38.1%, 29.9% and 29.3% higher than those of SCGP-E, respectively. The strongest anti-oxidant activity of SCGP-UAE was due to the UAE method degraded SCGP chains and exposed more sulphate groups by breaking glycosidic bonds within SCGP.

Automated summary

This study investigated the physicochemical properties and antioxidant activity of sea cucumber gonadal polysaccharide extracted using enzymatic, ultrasound, and ultrasound-assisted enzymatic methods. The results showed that the polysaccharide extracted by the ultrasound-assisted enzymatic method had higher total sugar and sulfate group content compared to other extraction methods. The antioxidant activity of the ultrasound-assisted enzymatic extracted polysaccharide was also higher in the tested concentration range.