Seaweed Flavors

Appears in
On Food and Cooking

By Harold McGee

Published 2004

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When it comes to flavor, the three seaweed families share a basic salty-savory taste from concentrated minerals and amino acids, especially glutamic acid, which is one of the molecules used to transport energy from one part of the seaweed to another. Seaweeds also share the aroma of dimethyl sulfide, which is found in cooked milk, corn, and shellfish as well as in seacoast air. There are also fragments of highly unsaturated fatty acids (mainly aldehydes) that contribute green-tea-like and fishy overtones. Against this common background, the three families do have distinctive characters. Dried, the red seaweeds tend to develop a deeper sulfury aroma from hydrogen sulfide and methanethiol, as well as flowery, black-tea-like notes from breakdown of their carotene pigments. When fried, dulse develops a distinct aroma of bacon. Some red algae, including the limu kohu of Hawaii (Asparagopsis), accumulate compounds of bromine and iodine, and can have a strong iodine flavor. The generally mild brown seaweeds have a characteristic iodine note (iodooctane) as well as a hay-like one (from the terpene cubenol). A few, notably species of Dictyopteris used as flavorings in Hawaii, have spicy aroma compounds that are apparently reproductive signals. Some browns are noticeably astringent thanks to the presence of tannin-like phenolic compounds, which in the dried seaweed form brown-black complexes (phycophaeins).