Extraction optimization, physicochemical characterization, and antioxidant activity of polysaccharides from Rhodosorus sp. SCSIO-45730

Na Wang; Lumei Dai; Zishuo Chen; Tao Li; Jiayi Wu; Houbo Wu; Hualian Wu; Wenzhou Xiang

doi:10.1007/s10811-021-02646-2

Extraction optimization, physicochemical characterization, and antioxidant activity of polysaccharides from Rhodosorus sp. SCSIO-45730

J Appl Phycol. 2022;34(1):285-299. doi: 10.1007/s10811-021-02646-2. Epub 2021 Nov 30.

Authors

Na Wang^{1

2}, Lumei Dai^{1

2}, Zishuo Chen^{1

2}, Tao Li^{1

3}, Jiayi Wu¹, Houbo Wu^{1

3}, Hualian Wu^{1

3}, Wenzhou Xiang^{1

3}

Affiliations

¹ CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301 People's Republic of China.
² University of Chinese Academy of Sciences, Beijing, 100049 People's Republic of China.
³ Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou, 511458 China.

Abstract

Microalgal polysaccharides have been reported in many studies due to their uniqueness, biocompatibility, and high value, and Rhodosorus sp. SCSIO-45730 was an excellent source of polysaccharides and β-glucans. However, the polysaccharides from the red unicellular alga Rhodosorus sp. SCSIO-45730 have barely been studied. In this work, hot water extraction of Rhodosorus sp. SCSIO-45730 polysaccharides (RSP) was optimized using response surface methodology (RSM) based on Box-Behnken design (BBD). The maximum RSP yield (9.29%) was achieved under the optimum extraction conditions: liquid-solid ratio of 50.00 mL g^-1; extraction temperature of 84 °C; extraction time of 2 h; and extraction times of 5 times. The results of physicochemical characterization showed that RSP had high sulfate and uronic acid with content of 19.58% and 11.57%, respectively, rough layered structure, and mainly contained glucose, galactose, xylose, and galacturonic acid with mass percentages of 34.08%, 28.70%, 12.46%, and 12.10%. Furthermore, four kinds of antioxidant assays were carried out, and the results indicated that RSP had strong scavenging activities on ABTS and hydroxyl radical and moderate scavenging activities on DPPH and ferrous chelating ability. These results indicated that RSP showed potential as a promising source of antioxidants applied in food, pharmaceutical, and cosmetics industry.

Supplementary information: The online version contains supplementary material available at 10.1007/s10811-021-02646-2.

Keywords: Antioxidant activity; Extraction; Optimization; Polysaccharides; Rhodophyta; Rhodosorus.