As we become more mindful of our planet’s and our own health, microalgae seems to get the attention it deserves. Could it be the food of the future?
Microalgae, also known as phytoplankton, is the first natural food. With an estimated number of species ranging from 200,000 to 800,000, these uni-cellular organisms –with size as small as 0.2μm– accumulate exceptional nutrients for both humans and animals. Although their nutritional value can vary depending on their cell size, digestibility, production of toxic compounds and biochemical composition, their major organic constituents are protein, lipids (omega-3 fatty acids) and carbohydrates.
Algal protein: a winner by all means
In most European countries, the main source for the dietary protein intake in adults is meat and meat-based products, followed by grains and grain-based products, milk and dairy products. However, current sources of proteins are not enough to cover the world needs. By 2050, the world needs to produce 50% more food and 70% more protein to feed 9 billion people (UN/FAO).
The protein content of many microalgal species can compete, quantitatively and qualitatively, with conventional protein sources. In terms of quantity, several species of microalgae are reported to possess very high concentrations of protein, ranging from 42% to over 70%. In terms of quality, microalgae contain all of the essential amino acids that mammals are unable to synthesize.
In addition, protein production from microalgae is much more efficient and sustainable compared to other sources. Animal protein sources consume 100 times more water compared to plant sources for equivalent protein extraction, while protein yield from microalgae is reported at 4–15 tons/Ha/year compared to terrestrial crops production of 1.1 tons, 1–2 tons and 0.6–1.2 tons/Ha/year for wheat, pulse legumes and soybean respectively.
Algal omega-3 oil competes with fish sources
Although fish has been the major source of omega-3, global interest has been shifting towards microalgae. The depleting fish population and drawbacks intrinsic to fish, such as limited expiry date, existence of impurities (e.g. heavy metals), microplastic pollution and other ocean stressors are growing the burden of the fish market. According to estimates, in 2030 there will be a shortage of 50.6 million tons of fish for human consumption (UN/FAO).
Microalgae are exceptional sources of fatty acids, especially the long-chain polyunsaturated fatty acids (PUFAs) such as γ-linolenic acid (ω-6), arachidonic acid (ω-6), eicosapentaenoic acid (EPA) (ω-3) and docosahexaenoic acid (DHA) (ω-3). Due to their rapid growth rate, microalgae can produce 10–100 times more oil than terrestrial oilseed plants.
100% sustainable
Besides its exceptional nutritional value, microalgae is 100% sustainable, meaning it is abundant, autotrophic and renewable. As it grows by photosynthesis, it uses solar energy, consumes carbon dioxide (CO2) and releases oxygen –in fact, every ton of algae consumes up to 1.8 tons of CO2 (UN/FAO).
In addition, microalgae grows 10 times more rapidly than terrestrial plants, while less than a tenth of the land is needed to produce an equivalent amount of biomass. It can be cultivated in non-productive and non-arable land and it can use fresh, brackish, saline or wastewater, and does not need any fertilizers.
