Algae in the Kitchen

By Home & Garden Last updated Tuesday, May/21/2024

Supplements

Some algae are consumed as dietary supplements. Spirulina is a common example in the United States. It's actually a type of cyanobacteria or "blue-green algae," as they are often called. Often sold as flakes and powders in health-food stores, spirulina is high in beta-carotene and various antioxidants. Chlorella is a freshwater algae popular as a supplement in some parts of Japan; it's claimed that this algae is rich in important nutrients.

Nori is the Japanese name for various species of red algae in the genus Porphyra. These algae are widely cultivated in Japan; about 133,000 tons of Porphyra are grown each year. After harvesting, the Porpyhra are chopped up and dried to form thin sheets. If you've ever eaten sushi before, you've seen these sheets already -- they are the material that becomes the black wrap around the rice in a sushi roll, and they're an important part of Japanese cuisine. With the growing popularity of sushi in America, they've become a familiar item in the United States as well.

At one time, the ice-cream industry relied heavily on gelatin as a thickener. More recently, however, they have turned to thickeners of plant or seaweed origin instead. Among these are carrageenan, an extract from red algae, and sodium alginate, a thickener produced from brown kelp, which is also a species of algae. Agar is another popular thickener in many foods; it's derived from a variety of algae, including species in the genera Gelidium, Pterocladia and Gracilaria.

Thickeners like alginate and carrageenan are used in all kinds of processed foods, so algae are more common in your kitchen than you might imagine. As illustrated by the history of nori, seaweeds have traditionally been popular in Asian cultures -- so popular they've left an interesting legacy. According to a 2010 study in the journal "Nature," gut bacteria from many Japanese people carry genes that enable them to efficiently break down molecules found in some seaweeds like Porphyra. These genes are absent in gut bacteria from North American people. Moreover, the evidence suggests these genes originally came from bacteria found on Porphyra algae. It's thought this exchange came about thanks to the abundance of seaweeds like nori in the Japanese diet.