Structure characterization and in vitro hypoglycemic effect of partially degraded alginate

Jiawei Chen; Qing Meng; Bo Jiang; Jingjing Chen; Tao Zhang; Licheng Zhou

doi:10.1016/j.foodchem.2021.129728

Structure characterization and in vitro hypoglycemic effect of partially degraded alginate

Food Chem. 2021 Sep 15:356:129728. doi: 10.1016/j.foodchem.2021.129728. Epub 2021 Mar 30.

Authors

Jiawei Chen¹, Qing Meng¹, Bo Jiang², Jingjing Chen³, Tao Zhang³, Licheng Zhou¹

Affiliations

¹ State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
² State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address: bjiang@jiangnan.edu.cn.
³ State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China.

PMID: 33836362
DOI: 10.1016/j.foodchem.2021.129728

Abstract

Alginate is a low-cost polysaccharide found abundantly in seaweeds which consists of mannuronate and guluronate, and it is considered a sustainable gum source for dietary fiber. To solve the high viscosity-related problems while retaining its physiological properties, four partially degraded alginate products (PDA1-4) with molecular weight of 1.05-0.40 × 10⁵ g mol^-1 and intrinsic viscosity of 170.9-38.9 mL g^-1 were enzymatically prepared and characterized. ¹H Nuclear magnetic resonance analysis showed the used alginate lyase had a preference to degrade guluronate-blocks. PDA1 and PDA2 presented random coil conformation, whereas PDA3 and PDA4 displayed compact spherical-coil conformation over random coil conformation in solution. In vitro assays suggested a glucose-adsorption capacity order of PDA1 < PDA2 < alginate < PDA3 < PDA4 and a glucose-diffusion retardation capacity order of PDA3 < PDA1 ≤ alginate < PDA2 < PDA4, indicating that partially degraded alginate reinforced the hypoglycemic effect, especially mannuronate-rich PDA4. Overall, the study may have important implications for development of PDA as dietary fiber with potential hypoglycemic activity.

Keywords: Alginate; Glucose adsorption; Glucose diffusion; Hypoglycemic effect; Partially-degraded alginate.

MeSH terms

Alginates / chemistry*
Alginates / pharmacology*
Glucuronic Acid / chemistry
Hexuronic Acids / chemistry
Hypoglycemic Agents / chemistry*
Hypoglycemic Agents / pharmacology*
Molecular Weight
Structure-Activity Relationship

Substances

Alginates
Hexuronic Acids
Hypoglycemic Agents
Glucuronic Acid