Optimization of Microwave-Assisted Extraction of Polysaccharides from <i>Ulva pertusa</i> and Evaluation of Their Antioxidant Activity

• Main Authors: Bao Le (Author), Kirill S. Golokhvast (Author), Seung Hwan Yang (Author), Sangmi Sun (Author)
• Format: Book
• Published: MDPI AG, 2019-05-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

The use of green marine seaweed <i>Ulva</i> spp. as foods, feed supplements, and functional ingredients has gained increasing interest. Microwave-assisted extraction technology was employed to improve the extraction yield and composition of <i>Ulva pertusa</i> polysaccharides. The antioxidant activity of ulvan was also evaluated. The impacts of four independent variables, i.e., extraction time (X₁, 30 to 60 min), power (X₂, 500 to 700 W), water-to-raw-material ratio (X₃, 40 to 70), and pH (X₄, 5 to 7) were evaluated. The chemical structure of different polysaccharides fractions was investigated via FT-IR and the determination of their antioxidant activities. A response surface methodology based on a Box&#8211;Behnken design (BBD) was used to optimize the extraction conditions as follows: extraction time of 43.63 min, power level of 600 W, water-to-raw-material ratio of 55.45, pH of 6.57, and maximum yield of 41.91%, with a desired value of 0.381. Ulvan exerted a strong antioxidant effect against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2&#8217;-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and showed reducing power in vitro. Ulvan protected RAW 264.7 cells against H₂O₂-induced oxidative stress by upregulating the expression and enhancing the activity of oxidative enzymes such as superoxide dismutase (SOD) and superoxide dismutase (CAT). The results suggest that the polysaccharides from <i>U. pertusa</i> might be promising bioactive compounds for commercial use.

Item Description

2076-3921
10.3390/antiox8050129