Extraction solvents influence physicochemical, structural, and functional properties of polysaccharides isolated from okra seeds: A comparative study

The present work investigated the physicochemical and functional properties of okra seed polysaccharides extracted by three different solvents, including molecular structure, antioxidant activities, pancreatic lipase, and α-amylase inhibitory activities. Extraction solvents showed remarkable influence on the extraction yield, structural composition, and functional properties of okra seed polysaccharides. Okra seed polysaccharides extracted by hot water, citric acid, and alkali were named as WOSP, COSP and AOSP, respectively. Results showed that arabinose (23.08 - 33.91%) was the main monosaccharide among three kinds of okra seed polysaccharides. The molecular weight of COSP (706.7 kDa) was much higher than that of AOSP (397.6 kDa). COSP had stronger pancreatic lipase and α-amylase inhibitory activities, but weaker antioxidant activities than AOSP. WOSP exhibited higher emulsifying activity (58.77%) and emulsion stability (57.77%) than COSP and AOSP. Thermal treatment significantly improved the emulsifying capacity among three kinds of okra seed polysaccharides, especially the creaming index which increased 190% in the case of COSP stored for 30 d. These results suggested that appropriate solvent could play crucial role in the structure of okra seed polysaccharides and their food potential application.