Optimization of microwave-assisted extraction of Sargassum thunbergii polysaccharides and its antioxidant and hypoglycemic activities

Beibei Ren; Chun Chen; Chao Li; Xiong Fu; Lijun You; Rui Hai Liu

doi:10.1016/j.carbpol.2017.05.094

Optimization of microwave-assisted extraction of Sargassum thunbergii polysaccharides and its antioxidant and hypoglycemic activities

Carbohydr Polym. 2017 Oct 1:173:192-201. doi: 10.1016/j.carbpol.2017.05.094. Epub 2017 Jun 3.

Authors

Beibei Ren¹, Chun Chen¹, Chao Li², Xiong Fu³, Lijun You¹, Rui Hai Liu⁴

Affiliations

¹ School of Food Science and Engineering, South China University of Technology, 381Wushan Road, Guangzhou, 510640, PR China.
² School of Food Science and Engineering, South China University of Technology, 381Wushan Road, Guangzhou, 510640, PR China. Electronic address: felichao@scut.edu.cn.
³ School of Food Science and Engineering, South China University of Technology, 381Wushan Road, Guangzhou, 510640, PR China. Electronic address: lfxfu@scut.edu.cn.
⁴ School of Food Science and Engineering, South China University of Technology, 381Wushan Road, Guangzhou, 510640, PR China; Department of Food Science, Stocking Hall, Cornell University, Ithaca, NY, 14853, USA.

PMID: 28732858
DOI: 10.1016/j.carbpol.2017.05.094

Abstract

In the present work, optimization of microwave-assisted extraction of polysaccharides from Sargassum thunbergii was investigated. The physicochemical properties, structural characteristics, and in vitro antioxidant and hypoglycemic activities were determined. The optimal extraction conditions with a yield of 2.84±0.09% for extraction of polysaccharides (STP-1) were extraction time 23min, microwave power 547W, extraction temperature 80°C, and the ratio of raw material to water 1:27g/mL. STP-1 contained 32.7% of total carbohydrate, 1.86% of protein, and 15.2% of sulfates. STP-1 had a major molecular weight of 190.4kDa, and comprised of arabinose, galactose, glucose, xylose, mannose, galacturonic acid, and glucuronic acid with molar percentages of 1.94, 30.7, 4.54, 23.2, 17.6, 8.11, and 13.9%, respectively. In addition, STP-1 showed strong antioxidant and α-glucosidase inhibitory activities, and could improve the glucose uptake in insulin-resistant HepG2 cells, suggesting that STP-1 can be exploited as a promising natural antioxidant and hypoglycemic agent.

Keywords: Antioxidant; Hypoglycemic; Microwave extraction; Polysaccharides; Sargassum thunbergii.