Characterization, immunomodulatory activity and digestibility in vitro of a novel floridean starch from Grateloupia filicina

Abstract

In this study, a new low molecular weight floridean starch was isolated and purified from Grateloupia filicina. The chemical structure was characterized, and the immunomodulatory activity and in vitro digestibility were determined. The molecular weight (MW) of the floridean starch was 2918 Da and the main links of the floridean starch were α-1, 4- glycosidic link or α-1, 6- glycosidic link. The floridean starch was C-type crystalline and mainly in flat disk and other irregular shapes. The immunomodulatory determination results showed that it can significantly activated macrophages release of NO and rapidly increased the secretion amount of IL-6. In addition, it was more easily digested compared with other traditional starches such as rice starch, wheat starch, and corn starch, because the glucose amount was highest during the entire determination process, which agreed with the quantity of starch that was digested in the first 20 min of pancreatic digestion phase (RDS, 40.43 %). Therefore, it is a good choice for hypoglycemic patients.