Sarah Bedolfe
It’s used in making many things -from pudding to paint, shampoo to sherbet- and it comes from seaweed!

Focusing on science, technology, engineering, and math (STEM), as they pertain to the ocean.

The term algin includes several related compounds that come from seaweed. Algin has seemingly endless uses – from manufacturing and pharmaceuticals to the food industry – as a gel that helps thicken and stabilize different products.

Brown algae is one of three types of seaweed (the others are red and green algae). Alginic acid is found in the cell walls of brown algae. Each seaweed species has a different form; for example, while giant kelp (Macrocystis pyrifera) is a good source of algin, the levels in the Sargassum species are very low.

The seaweed Durvillea is a common used source of algin. Photo by B.navez via Wikimedia Commons, Public Domain.

Seaweed can be collected from the shore, cut from wild stocks, or even farmed. The vast majority of the world’s seaweed is harvested in Asia, but seaweed also comes from other places around the world. Once the seaweed is harvested, alginic acid can be extracted and converted to sodium alginate, which is a salt.

Seaweed farms in Indonesia. Photo by Hassan Abdel-Rahman via Wikimedia Commons, Public Domain.

Algins have properties that make them useful in a wide variety of applications. They are mostly used for altering a product’s texture, by thickening or stabilizing. Since they are tasteless and odorless they can be added to foods without changing the flavor; since they are mostly colorless they can be used in paints and dyes without affecting the hue. 

Algin has countless uses in the food industry. In many foods, such as ice cream, sorbet, yogurt, and other dairy products, algin is used as a thickener. As a gelling agent, algin is commonly used to give jam, pudding and pastry filling a gel-like texture.

Photo by Paul Wilkinson via Flickr, Creative Commons. 

Algin helps prevent separation of ingredients as a stabilizer in gravies, soups, and sauces. It can also similarly be used as an emulsifier, which helps blend together substances that don’t normally mix, for items such as oil and vinegar salad dressing.

And it’s not just for human food – algin is often used to give pet food its texture, as well!

Since it’s a foaming agent, algin can also be used in beer to help maintain its head

Algin has many pharmaceutical applications, as well. In medicine tablets it can be used a binding agent to hold them together, and then to help them disintegrate in the stomach. It may be included in throat lozenges as a demulcent, something that soothes and protects mucous membranes with a thin film. It may also be used in antacid medications to form a coating in the stomach to protect from acid reflux and indigestion.

A unique medical purpose for a certain type of algin – calcium alginate – has been found for wound dressings. The fibers are absorbent and take in fluid, creating a moist healing environment that can also be rinsed away with a saline solution for easy removal.

The dental field has multiple uses for algin as well. Dental molds use it as a gelling agent and it also acts as a thickener, creating the texture and binding the ingredients, in toothpaste.

Photo by Scott Ehardt via Wikimedia Commons, Public Domain.

One of algin’s most common applications is in manufacturing: it is often used as a thickener for textile dyes, which can help give a more precise application of the color onto the fabric. In fact, the textile industry accounts for about 50% of algin use worldwide. It is similarly used in paint for thickness, and to stabilize the mix of pigments. In paper manufacturing, paper may be given a coating containing algin to give it a smooth surface.

In cosmetics, algin is used to create a gel coating in face masks. It is also found in many other cosmetic products, like shampoo and lotion, as well. In lipstick, algin is used to help maintain a smooth texture that stays on the lips.

These are still just a few of the uses for algin – and there are many other seaweed products and substances on the market as well, making the harvesting and use of marine algae a global industry.




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