Study of Fucoidan Digestibility via an in Vitro Digestion System
Fucoidan is a known health product mainly consumed orally. It is important to investigate the digestibility of fucoidan in order to understand how fucoidan exerts its health benefits.
Our objective for this project is discussed under the following sub-headings: To study the digestion pattern of fucoidan using in vitro models. And to compare different in vitro models for a digestibility study of fucoidan.
Sample digested through the two different digestion models showed an increase of the reduced sugar which infer to the breakdown of the polymer to smaller units, such as glucose and galactose. Sulfate levels which contribute to the biological activities of fucoidan decreases significantly during the digestion process. It has also been observed that the level of uronic acid, which is linked to anticoagulant and antitumor property of fucoidan, increases during the digestion process. Also, the level of monosaccharides in fucoidan is increased during digestion process. This may be due to the anti-peptic activity of fucoidan, which breaks down the sulfate-fucose bonds and bind the sulfate compounds with protein.
In order to determine the reaction through different stages of digestion, GC-FID assay was used to test the individual monosaccharides from different reactors during the digestion process. Results showed that the oral digestion process and gastric environment without enzyme almost had no influence on the digestibility of fucoidan. But the pepsin worked in the stomach reactor, significantly increased the level of monosaccharides (mainly fucose) in fucoidan digesta. These changes may relate to the protein contained within the fucoidan structure, enzymolysis by pepsin and contribute to the broken down of polymer.
Overall, the results showed that fucoidan is digestible. The digestibility of the polymer is probably related to the anti-peptic activity of fucoidan and enzymolysis of protein within fucoidan.
In the future, it should be investigated as to, how we can increase or maintain the high sulfate level in digested fucoidan as biological activities of fucoidan is related to a high sulfate content of fucoidan.