Polysaccharides from brown marine algae could provide the ingredients for a new wave of beverages with health benefits, according to researchers in Ireland.
Franck Hennequart, a scientist with the biochemistry department at the National University of Ireland in Galway, said he and his colleagues have developed a process to extract alginates, laminaran and fucoidans from brown algae. While alginates from brown algae are currently used as stabilisers in beverages, no major industrial application has emerged in the functional segment for laminarans and fucoidans, he said. Alginates are currently used as low-cost thickening and viscosity stabilisers for such products as salad dressings, and for microencapsulated ingredients. Laminarans are used in horticulture, but otherwise have no other industrial applications. Fucoidans are used as bioactive agents in Asia. The scientists began developing a way to commercially extract the laminarans and fucoidans from the algae after studies indicated both had potential uses as immuno-stimulant, anti-viral and anti-cancer agents. The natural extraction process is non-destructive, allowing the scientists to show that some of the polysaccharides have distinct anti-viral and anti-bacterial effects. Some of the extracts were tested against nine pathogens, including E. coli, listeria, staphycococcus, and salmonella. In the case of sodium alginate, the compound bound itself to E. coli, making it a potential food safety tool. The ingredient also stopped staphycococcus from growing. "Sodium alginate seems to demonstrate a strong anti-bacterial element," he said. "It not only binds but kills." Most commercially produced sodium alginate ingredients do not demonstrate any biocidal effect, he noted. Meanwhile crude fucodians seem to demonstrate a "good" prebiotic effect, he reported. The scientists have now produced and identified four different extracts from the seaweeds, standardised their composition and are now testing them on a range of drinks, including mineral water, orange juice and cold tea. "The raw extract failed in most sensory tests," Hennequart said. The scientists then tested the resulting beverages for their effects on the same bacteria. Potential toxilogical effects of the extracts and the test beverages are being studied through tests on rats. So far no toxicity has been discovered, he said. Some of the extracts seem to have an anti-inflammatory effect, he said. Some of the problems to be overcome include methods to ensure quality control. The studies and their conclusions will help guide the selection of candidate functional beverages for commercialisation, Hennequart said. The scientists are working on developing an extraction method that can produce the extracts in the amounts necessary for commercialisation. They are currently looking at developing products for the market in Japan. The team has made contacts with Ireland-based beverage companies to develop the products. The market for functional foods and drinks is forecast to grow by 14 per cent a year until 2010. In 2005 the market had a value of $73.5bn, he said.
Hennequart made the presentation on the work at the two-day Health Sea International Symposium in Granville, Normandy. The conference ended 5 October.