Seaweed extract is a concentrated product derived from various types of marine algae, containing a rich blend of compounds from the ocean. This extract harnesses the beneficial properties of seaweeds, which are known for their resilience in marine environments. It contains a complex mix of bioactive molecules, making it a versatile ingredient with wide-ranging applications in agriculture, skincare, and nutrition.
The Making of Seaweed Extract
The production of seaweed extract begins with the selection of marine algae species. Common types include brown algae like Ascophyllum nodosum (knotted wrack) and Ecklonia maxima (kelp), along with various Fucus and Laminaria species. These seaweeds are harvested sustainably, often from pristine coastal waters. After collection, the raw seaweed is rinsed to remove salt and impurities.
Several methods are employed to produce the concentrated extract, each designed to isolate different beneficial compounds. These techniques range from physical processes to chemical extractions. Common approaches include cold pressing, cold blending (micronizing seaweed in water), and hot water extraction. Other processes may involve alkaline hydrolysis, mild acid extraction, or fermentation, which transforms raw seaweed into a slurry from which the liquid extract is collected.
Applications in Agriculture and Horticulture
Seaweed extract functions as a biostimulant in agriculture and horticulture, distinct from traditional fertilizers, by stimulating natural plant processes rather than solely providing nutrients. While containing some macronutrients, its value lies in a complex array of bioactive compounds. These include natural plant growth hormones like auxins, cytokinins, and gibberellins, which promote root development and enhance overall plant vigor. It also contains polysaccharides, alginic acid, betaines, and amino acids that contribute to plant health.
The extract helps improve a plant’s resilience to various environmental stressors. For instance, it can enhance tolerance to drought, frost, salinity, and extreme temperatures. This improved resilience is partly due to the extract’s ability to trigger the plant’s stress response. Additionally, seaweed extract can improve nutrient uptake efficiency, making micronutrients like iron, manganese, zinc, copper, and boron more available to plants, leading to robust growth and increased crop yields.
Use in Skincare and Cosmetics
In skincare and cosmetics, seaweed extract is valued for its beneficial compounds that support skin health. It contains polysaccharides like alginates, laminaran, fucoidan, and carrageenan, known for their hydrating properties. These polysaccharides can form a protective film on the skin, helping to lock in moisture and improve the skin’s barrier function. The extract is also a source of proteins, peptides, amino acids, lipids, and vitamins, all contributing to skin nourishment.
Seaweed extract exhibits antioxidant properties due to the presence of vitamins C and E, polyphenols, and other phytochemicals. These antioxidants help protect skin cells from damage caused by environmental factors like free radicals, which can contribute to premature aging. Additionally, compounds within the extract, including polysaccharides and phenols, have anti-inflammatory effects that can soothe irritated skin and reduce redness. This broad spectrum of benefits makes seaweed extract a common ingredient in products like hydrating serums, nourishing moisturizers, and revitalizing masks.
Nutritional and Supplemental Role
Seaweed extract serves as a concentrated source of various minerals when consumed as a dietary supplement. It is recognized for its high iodine content, a mineral that is often less abundant in land-based foods. Iodine plays a direct role in the synthesis of thyroid hormones, which regulate metabolism and growth. Beyond iodine, the extract also provides other trace minerals like iron, zinc, manganese, calcium, and magnesium, contributing to overall nutritional intake.
The iodine concentration in seaweed extract varies significantly depending on the species of algae and the processing methods used. Brown seaweeds, such as kelp and kombu, contain higher levels of iodine compared to red or green varieties like nori or dulse. Due to this variability, consuming excessive amounts of certain brown seaweed extracts can lead to iodine intake above recommended tolerable upper limits. For instance, even a small serving of some brown seaweeds, like kombu, can exceed the adult daily upper limit of 600 micrograms, and for pregnant women, it can surpass their recommended range of 900-1100 micrograms per day. Therefore, it is suggested to limit the consumption of high-iodine brown seaweeds, especially for sensitive populations like pregnant women and children, to about once per week.