Uses of Marine Algae

Different types of marine algae have been used as food by coastal peoples all over the world for centuries.

“That’s nice,” you say, “but I’m not eating pond scum and sea lettuce!”

Don’t place any bets on that statement. Depending on the time of day that you are reading this article, you have likely already ingested products extracted from marine algae. From the creamer in your morning coffee, to the mayonnaise and bread (unless you made them yourself) for your lunch sandwich, to the dressing on your evening salad, and the ice cream you ate for dessert, you ate marine algae. If you wore make up, you used marine algae. If you used toothpaste when you brushed your teeth, you used marine algae. If you were fed baby formula as an infant, you have ingested marine algae all your life.

Having some doubts about those statements? Head to your pantry and look at some labels. Look first for carrageenan. Carrageenan, sometimes spelled carrageenin or carragheen, is an additive derived from several species of red algae. It is principally used as a thickening and stabilizing agent without adding flavor. It is harmless and is used in frozen foods, pastry fillings, syrups, jams & jellies, cake icings, sauces and gravies, puddings, salad dressings, whipped toppings, skim milk, evaporated milk, chocolate milk, processed cheeses, cottage cheese, infant formulas, custards, yogurt, creamy canned soups, and commercial ice cream. Those little containers of non-dairy creamer that you get at some restaurants contain carrageenan. Read the label while waiting for your order to arrive. Carrageenan is used in lotions and creams, capsules and tablets, shampoos, and toothpastes.

Agar is another common addition to commercial food products. It is familiar to many people as the medium on which bacterial cultures are grown in the laboratory, but that gel is also used for thickening, suspending, and stabilizing foods. Agar is used as an anti-drying agent in breads and pastries (longer shelf life), in the manufacture of processed cheese, mayonnaise, puddings, creams, jellies, and in frozen dairy products. It is also used in photographic film, shoe polish, dental impression molds, shaving soaps, and hand lotions. Agar is made from the red algaes of the genus’ Gelidium, Gracilaria, and Pterocladia. Gracilaria is easily collected in St. Joseph Bay.

Various alginates may show up on labels. Alginates are cell-wall constituents of brown algae (Phaeophyceae), like the giant kelps off California. Kelp harvesting ships move through kelp beds gathering the kelp fronds using a conveyor-like device on the prow of the ship. Kelps are some of the fastest growing plants in the world.

But marine algae are not always invisible in food. There are plenty of traditional dishes that incorporate seaweed. Perhaps the best known species of algae that are used as food are species of Phorphyra, or nori as it is known in Japan. This is a membranous red algae that is dried and used as the outer covering of a rice sandwich (sushimi), and in soups and in other dishes as well. It is readily available in this country in certain natural foods supermarkets and Asian markets.  While most traditional uses of seaweed are from the Orient and Polynesia, seaweed is a component of many traditional dishes in Northern Europe and New England as well.

Two species used in food preparation are Rhodymenia palmata, known in Scotland and New England as dulse, and Chondrus crispus or Irish Moss.  Segments of R. palmata were sweetened, flavored, and used as candy.  Chondrus crispus was cooked with milk and flavoring and made into a pudding known as blanc-manges. Marine algaes are high in vitamins and various necessary trace elements and have become popular with health conscious consumers. Supplements made from marine algaes have become trendy.

The marine algaes are simple in structure and more primitive than the plants we encounter on land.  Algae grow in shallow water where light can penetrate.  They attach by “holdfast organs,” or anchoring devices, not true roots.  Roots absorb water and minerals from the soil, but algae can absorb them from the water surrounding them. Algae have no flowers, fruits or edible tubers.  If conditions are right, marine algae demonstrate phenomenal growth rates, and are ideal for cultivation.

There has long been a cottage industry in harvesting red algae from the shore, but commercial cultivation has increased in order to meet the demand for algae products.  Many western companies grow the target species in tanks on shore.  These are found around Maine, New Brunswick, and Nova Scotia.  There was once an industry growing red algae in seawater-filled pits in the Florida Keys, with its customers primarily being the cosmetics industry.  Markets for marine algae are growing.  Ireland and Northern Ireland are showing renewed interest in seaweed as a part of the traditional diet, and seaweed has been cultivated on a huge scale in China, Korea and Japan for centuries.  The total annual production of nori in Japan alone is estimated to be more than $2 billion.

Marine algae species may also hold promise for feeding large numbers of people. With the current movement toward consumers embracing organically grown foods and healthier food sources, marine algae may become more available – and accepted – in dishes.   After all, you’ve already been eating seaweed and didn’t know it.
Tom Baird has been a fisheries biologist, high school and community college teacher (oceanography and microbiology), director of a science and environmental center, teacher of science and principal in Pinellas County as well as an educational consultant. He retired from the Florida Department of Education and he and his wife divide their time between Tallahassee and Cape San Blas.

Photo: Carrageenan, a food additive used as a thickening or stabilizing agent in many common products, is derived from species of red algae.

View original article at: Uses of Marine Algae

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