H. Arif Ustaoglu
Used extensively in the food industry, and serve as the raw material for plant fertilizers and many drugs used to fight diseases, seaweeds (or algae) are multicellular organisms that grow and develop in seas, rivers, and lakes. They can thrive in both saltwater and freshwater environments. They are classified as plants since they can produce carbohydrates by utilizing solar energy, carbon dioxide, and water. They can be green, brown, or red. While red and brown seaweed can be solely found in oceans, green seaweed lives in freshwater bodies (rivers and lakes), and even on land (on rocks, walls, and trees). Most marine seaweeds have to attach themselves to something to survive; only a few species can develop while drifting freely at sea. The sizes of different seaweeds vary according to the composition of the water, and the climate. Among all known plants, the leaves of fastest growing giant Pacific Ocean seaweed, Macrocystis pyrifera, can grow from 3–4.5 meters in a week. A single branch of these plants can be 60–100 meters long and 100 kilograms in weight. Seaweeds have parts resembling leaves and stems, but they lack a network of veins.
Algae plays a huge part in two natural cycles. They convert solar energy into chemical energy in aquatic environments and thus make the first ring of the food chain. Marine algae also produces two thirds of the world’s demand for photosynthetic carbon: the oxygen necessary for life is provided by the photosynthesis algae carries out. After fulfilling this role, they are then consumed by zooplanktons, which along with phytoplankton are eaten by small fish; bigger fish then eat the small fish; and these are eventually consumed by humans and larger carnivores. When these larger predators die, they become food for insects and bacteria, while also leaving their remains as nourishment for plants.
At first sight, we may see organisms in a struggle with each other; however, when we observe the entirety of life, we notice that all creatures are made to assist one another without being aware of it.
Algal foods and health care
Algae are also used directly in food for humans. Especially in Ireland, Wales, and Asian countries, algae is an important food source. It is rich in A, B1, B2, B6, and C vitamins, in addition to niacin, iodine, potassium, iron, magnesium, and calcium. Approximately 70 types of seaweed are consumed in China; in Japan, around 20 different kinds are used in cooking.
Seaweed can be eaten raw, cooked, or in other forms. In China and Japan, brown seaweed (Laminaria, Undaria or Ecklonia species) is consumed in dehydrated form. These help as expectorants and as a source of iodine. Algae is also recommended for cancer treatments in Chinese and Indian literature. In Korea, mothers follow a seaweed rich diet for three months after giving birth.
Various vitamins are also produced from these organisms. Certain algal species are cultivated as “supplementary foods” and sold in packaged forms. Much of the worldwide demand is fulfilled by Ireland, Scotland, and Norway.
Products prepared from brown seaweed can also be used as antidotes. Iodine and other elements contained in the seaweed prevent the absorption of some radioactive materials in the body. In recent studies, the active ingredients obtained from Undaria brown seaweed were found to eliminate harmful aromatic substances in mice. They were also shown to play a role in the prevention of infections related to the EBV, HSV, and HIV viruses, which can be associated with cancer and cause cold sores, chicken pox, and shingles. Furthermore, an algae rich diet was discovered to improve health and increase disease resistance in sheep and cattle.
The brown seaweeds Laminaria and Fucalesgrow naturally, especially on the American oceanic coasts. There are nearly 30 different types of these seaweeds, and they are the natural sources of iodine, which aids the thyroid and is important for human metabolism and development. Due to well-known benefits, there are many commercial brands of shampoos, soaps, creams, vitamin supplements, and diet products that include brown seaweed.
Algae in the pharmaceutical industry
In recent times, algal products have gained significance due to their cholesterol lowering, anti-cancer, and immune-system enhancing effects. As a sulfate containing polysaccharide that is exclusively found in brown seaweed, the antioxidant and anti-tumor effects of fucoidan have been demonstrated. Fucoidan helps the heparin sulfate receptors in charge of preventing in-vivo clotting of blood. It has also been shown in experiments performed on animals that fucoidan is a very powerful antiviral: it is in charge of the leukocyte transport to tissues and helps prevent metastasis.
It’s possible that seaweed heavy diets have contributed to the frequency of breast cancer in Japan and Korea being nine times lower than in the West. During experiments on animals, it was shown that brown seaweed and products derived from them help fight breast cancer, lung metastasis, and leukemia. The presence of iodine, tryptophan, fucoidan, or vitamins in the bodies of animals supports this conclusion.
The long life span and health of the Japanese people residing in Okinawa is associated with their seaweed-enriched nourishment.
Algae as a fertilizer
Algae have a positive impact on soil productivity and plant growth. It’s widely used in agriculture. Studies have shown that algae regulates the soil structure and improve its moisture capacity. The alginic acids contained in seaweed react with the metals in soil and become inflamed in humid climates. As result of this, the soil is rich with particles and nutrients. It becomes enriched with plenty of macro and micro elements (N, Ca, Mg, Mn, B, Br, I, Zn, Cu, Co) in addition to plant growth hormones (Auxin, Cytokinin, Gibberellins) and compounds like betaine. These are broken down to support the growth of beneficial soil bacteria (Rhizobium etc.). As such, root systems develop better, and the plants grown from the soil are healthier.
Oceans and seas host one vital ring of the worldwide food chain because of the algae they shelter. Algae serves mankind not only as a food item, but also because of its rich compounds that aid both natural and pharmaceutical growth. Though often overlooked, algae is one of our great blessings.
Some additives obtained from algae
Thickening and emulsifying agents are used to process meats like sausage or bologna, as well as in other foods. Some of these substances are derived from algae. These are primarily substances like “alginate,” “agar,” “carrageenan,” and “gel.” Large amounts of algae are collected for this purpose.
Carrageenan: It is first obtained from the red Irish seaweed. One of the important features of carrageenan is that it can form gels of different textures when used in low concentrations in water and milk based foods. Therefore it is used in the food industry as a gelling, binding, thickening, and stabilizing agent. Carrageenan is utilized in dairy products, dairy gels, in pie fillings, frozen foods, frozen desserts, and in pasteurized and sterilized milks.
Alginate exists as the insoluble salts of calcium, magnesium, potassium, and sodium in the cell walls of brown seaweeds. This substance is used for improving fruit structure, in frozen gel preparation, for extending storage time of potatoes, to obtain a softer texture, and to delay the formation of ice crystals in ice creams.
Agar has different features depending on the seaweed of origin and production method. It can have a very elastic jelly structure or be very fragile. It is used as an agent to enhance the lifespans of fruit pie fillings, cake creams, filo dough, and similar bakery products.
- Helen Fitton, J., Brown Marine Algae: A Survey of Therapeutic Potentials, Alternative and Complementary Therapies, February 2003.