Polski
Feedback, In this issue, Issue 14/2025
Algae, the green food of the future
Sep
One of the greatest challenges of civilization today is ensuring the food security of the ever-growing human population. Current ways of obtaining food, which primarily include expansive agriculture and commercial animal husbandry, contribute greatly to the degradation of natural environmental resources. It is therefore necessary to seek alternative sources of valuable food, the production of which will not have a destructive impact on the environment.
In recent years, algae have become increasingly popular in culinary applications – both macroalgae (macroalgae), visible to the naked eye, and microalgae (microalgae), which can only be seen under a microscope. Although their use for nutritional purposes has a centuries-old tradition, it is really only in recent decades that these organisms have gained widespread recognition, and the value of the global market involving algal products is steadily increasing. This is related to the increasing popularity of dishes from Asian cuisine (such as sushi), in which algae are an indispensable element, as well as the growing awareness of the need for healthy eating and the use of natural and minimally processed products in cooking.
Low requirements mean easy cultivation
Algae need much less demanding conditions than classical cultivated plants for proper development. In fact, most species are sufficient with adequate light intensity and a balanced concentration of macro and micro nutrients in the nutrient solution. Cultivation of algae does not require specialized treatments, which are normally carried out in agricultural fields, thus reducing the need for specialized agricultural equipment. Bioreactors, which are the basic cultivation equipment in commercial algae cultivation, can be laid out in places where classic agricultural fields could not be.
In recent years, for example, the popularity of locating bioreactors or vats of algae on the roofs of buildings has been growing. Algae cultivation, compared to crops, also uses much less water, and during its growth no chemical protection measures are required, as is the case with classical earth crops.
Algae – what exactly are they?
Algae is an artificial term that encompasses many organisms that belong to different taxonomic ranks. All organisms classically classified as algae belong to the kingdom of eukaryotes, and therefore have a nucleus in their cells. Most of them perform photosynthesis, but there are also species that are myxotrophs – able to feed autotrophically in the absence of light. Some species are completely devoid of photosynthetic pigments and autotrophy is the only way they obtain organic compounds.
Algae, although originally aquatic organisms, today should be classified as cosmopolitan organisms that inhabit a variety of environments. They can be found in both fresh and salt water – oceans, seas, large lakes and small puddles. They inhabit rushing rivers and small streams. They are also found in other habitats – on the bark of trees, the walls of buildings, and they also form bioshells on soils or rocks. Some species have adapted to live in extreme environments, such as hot springs, extremely saline bodies of water, Arctic regions and desert areas.
In popular opinion, algae are associated with green seaweed thrown ashore by sea waves. This association is most correct, as seaweed is the popular term for macroalgae. However, it should be remembered that algae also include many microscopic species, whose shapes, colors and adaptations to their lifestyle can really amaze. Some researchers also include cyanobacteria (cyanobacteria) among microalgae, although these organisms differ significantly from standard eukaryotic representatives. Cyanobacteria do not have a cell nucleus – they belong to the kingdom of prokaryotes. They are primarily united with algae by their aquatic habitat, as well as their ability to perform photosynthesis. In terms of cell biology and physiology, however, there are a number of significant differences between cyanobacteria and eukaryotic microalgae.
The use of macroalgae for nutritional purposes
Macroalgae for nutritional purposes have been used since ancient times. In fact, it can be assumed that the population, along with the settlement of coastal areas, both out of necessity due to problems with classical crops on the coasts and because of the flavorful qualities of seaweed, used these organisms for cooking from the very beginning.
The first archaeological evidence of the use of seaweed in cooking and as ingredients in medicines comes from Chile and dates back 14,000 years. In China in 500 BC, meals were prepared using macroalgae, and in Greece at the time of Hippocrates, ashed seaweed was used to create medicinal concoctions. Macroalgae were also consumed in Europe: in the British Isles and by the island peoples of Scandinavia, Spain, Portugal and France. Seaweed was consumed as a side dish, as a salad, when dried, or in baked chip-like forms. In some countries, such as Ireland, seaweed made it possible to survive periods of famine.
Today, macroalgae are consumed all over the world, but are most popular in Asia. Seaweed is a staple of Japanese and Korean cuisine, and is also an important culinary element in China, Malaysia and Vietnam, among others. Dishes containing macroalgae in Asian cuisine are mainly sushi rolls, but also soups or salads, dishes with rice or noodles. When powdered, some species are used as condiments.
Macroalgae cells have been shown to contain complete protein, desirable carbohydrates and lipids (such as omega-3 fatty acids). In Europe, the tradition of eating algae is maintained – most often in coastal countries, although in recent years dishes with algae have also become increasingly popular in places where this is not the custom, including Poland. The largest commercial cultivation of algae is carried out in China, India and Malaysia. Special ropes are stretched in designated areas of a body of water, on which seaweed growth and propagation is possible. This method is safer for the environment than direct extraction of organisms from their natural habitats. It is estimated that the global use of seaweed in the food industry will increase continuously.
The use of microalgae for nutritional purposes
Sources documenting the historical use of microalgae for nutritional purposes are far fewer than those mentioning macroalgae. The first references to the culinary use of microalgae concern cyanobacteria of the genus Nostoc sp. and Arthrospira sp. and date back to the first century in China.
Foods prepared with cyanobacteria were also known to the Aztecs, Mongolian peoples and Africans. Even today, dishes with cyanobacteria are eaten – mainly in China and Africa. The husks of Nostoc sp. are consumed when dried, at which time they resemble hair – hence, in free translation from Chinese, the genus can be described as a hair vegetable.
People living around Africa’s Lake Kossorom (Chad) collect the cyanobacteria that live in it, and then dry them in the sun in previously prepared earthen pits. They are then formed into eatable pancake-like structures. Cyanobacteria belonging to the Arthrospira genus are most commonly used there. These species are used to create dietary supplements, known by the trade name spirulina.
In recent years, there has been growing interest in eukaryotic microalgae, which are a potential source of valuable compounds that could find applications in the food industry, among other things. This practice can be traced back to the past – green algae of the genus Chlorella were even sent into space, where their usefulness in the diet of astronauts was tested. It is estimated that in the near future microalgae, like macroalgae, will be more strongly exploited, among other things, as a potential source of human food.
Michal Adamski – PhD in biological sciences, assistant professor at the W. Szafer Institute of Botany of the Polish Academy of Sciences. Leader of a team working on compounds synthesized by cyanobacteria and algae. Co-author of dozens of scientific publications. He is currently pursuing a research grant under the Science for Society II program entitled: Can algae be a valuable component of the human diet? (NdS-II/SP/0234/2024/01).
In the article I used, among others:
Adamski M., Flakus A., Kaminski A., Piątek J., Solarska M., Zmudzki P. (2024). The first report of the production of anatoxin-a by Bolivian terrestrial cyanobacteria. Acta Societatis Botanicorum Poloniae, 93, 177923. https://doi.org/10.5586/asbp/177923
Araújo, R., Peteiro, C. (2021). Algae as food and food supplements in Europe. Technical report by the Joint Research Centre (JRC), the European Commission’s science and knowledge service. https://doi.org/10.2760/049515
Ferreira de Oliveira, A.P. & Bragotto, A. (2022). Microalgae-based products: Food and public health. Future Foods, 100157.https://doi.org/10.1016/j.fufo.2022.100157
Kim, J. K., Yarish, C., Hwang, E. K., Park, M., Kim, Y. (2017). Seaweed aquaculture : cultivation technologies, challenges and its ecosystem services. Algae, 32(1), 1-13. https://doi.org/10.4490/algae.2017.32.3.3
