Umami taste, free amino acid composition, and volatile compounds of brown seaweeds

Umami taste is associated with deliciousness and was first suggested as a basic taste by Kikunae Ikeda in 1909 when he discovered that the brown seaweed konbu (Saccharina japonica), used to provide aqueous extracts for the Japanese soup stock dashi, contains very large amounts of free glutamate. We have performed a comparative analysis of the free amino acid contents of 20 different species of brown seaweeds used for human consumption from around the world, belonging to the 12 genera Nereocystis, Macrocystis, Laminaria, Saccharina, Undaria, Alaria, Postelsia, Himanthalia, Ecklonia (former Eisenia), Sargassum, Fucus, and Corda. We furthermore measured mineral and iodine contents as well as identified a range of volatile compounds and estimated their influence on the perception of umami taste. The results provide a basis on which chefs and food producers can control umami sensation in food items using some of the most popular species of edible brown seaweeds.