Application of in vitro Bionics Models for Speciation Analysis and Bioavailability Assessment of Trace Metals in Marine Algal Soup
Two new bionic technologies, i.e. in vitro bionic digestion and bionic biomembrane extraction, were developed for the pretreatment of marine algal soup. The soup of Laminaria japonica and Porphyra haitanensis was digested at 37 ℃ under the action of saliva, the acidity of the stomach or intestine with the inorganic and organic compounds(including digestive enzymes) that were found in the stomach or intestine, and then the chymes were obtained. Being similar to the biomembrane between the gastrointestinal tract and blood vessels, monolayer liposome was used as biomembrane model. Monolayer liposome-bonded(MLBMs) was used for oral bioaccessibility assessment of trace metals(Fe, Mn and Zn) in the chyme. The species distribution and bioavailability of trace metals in marine alga were obviously affected by the existence of the bioenzymes. Based on the concentration of MLBMs and whole-bionic digestion, the main absorption site of trace metals in marine algal soup was proposed as follow: iron in both Laminaria japonica and Porphyra haitanensis was absorbed mainly in stomach; manganese and zinc in Laminaria japonica were absorbed mainly in intestine and these two metals in Porphyra haitanensis were absorbed both in stomach and intestine.