The Science Behind Purple Irish Sea Moss Application and Nutrition

One of our most popular seaweeds to date, Purple Irish Sea Moss (Chondrus crispus) has had a long history of human consumption. Components of the macroalgae have application in various commercial products including, but not limited to, food ingredients. If you have ever read the ingredient list on some of your favorite food items (see: ice cream!), you may notice in the small print the word “carrageenan” listed. Carrageenan is an extract of Purple Irish Sea Moss, generally used as a thickening agent in the food industry. Carrageenan has other uses besides being a food additive; as demonstrated in the images below, it can also be used in paper marbling.

Carrageenan Powder to be used for paper marbling, sold by the London Centre for Book Arts.

These marbled paper journals can be bought from Blue Sky Papers.

Agar-agar is another product extracted from seaweeds with similar applications in food and industry. Popular in desserts in Asia, and used as a solid substrate for cell culture and microbiology work, agar-agar can be derived from another red seaweed often confused with Purple Irish Sea Moss called Gracilaria. For information on telling these two species apart, check out our handy Irish Moss Cheat Sheet.

For carrageenan, industrial extraction methods involve digesting a mixture of the seaweed and an alkaline earth metal hydroxide in water heated to 98C (208F), just slightly cooler than water’s boiling point. Some examples of alkaline earth metal hydroxides include Lithium Hydroxide (LiOH), Sodium Hydroxide (NaOH), and Potassium Hydroxide (KOH). The presence of the hydroxide ion (OH-) is what makes the compounds basic, or alkaline.  Occasionally, industrially processed seaweed will be pretreated with a dilute acid, which is shown to improve yield of carrageenan extraction. In that way, the industrial method is similar to how some of our own customers have told us they prepare their Purple Irish Sea Moss.  According to Gina Marie on her blog, Vegan with Curves, it’s important to rehydrate dried Irish Moss in water with cut limes, a dilute acid. The rehydrated seaweed should then be blended with water that has been boiled and slightly cooled.

Four out of six steps from Gina Marie’s instructional guide to making Irish Moss Gel.

Irish Moss gel blend from one of our customers, founder of the growing brand Light Body Herbals, whose Purple Irish Sea Moss gel is so thick, it can be hung upside down without moving from its container!

In industry, the addition of the base, AKA the alkaline earth metal hydroxide, is what separates the carrageenan from the Chondrus crispus plant matter. Our customers enjoy Purple Irish Sea Moss as a whole plant, blended up and added to all sorts of recipes. Inspired by some of our customers’ accounts, we have even done some experimenting with Chondrus crispus in recipes here at Gulf of Maine, Inc. headquarters! Many of the people we sell to claim that daily consumption of Purple Irish Sea Moss has terrific benefits for their health, immunity, and overall well-being.

The industrial separation of carrageenan from the whole Irish Moss plant may result in a significant loss of nutrient density. It is the many fat-soluble pigments (lutein, beta-carotene), antioxidants (small volatile compounds that terminate chain reactions caused by free radicals), and chromo-proteins (refer to our last blog post about phycobilisomes!) present in the Chondrus crispus cell structure which are thought to be the components that contribute to its nutritional value. The isolation of carrageenan from Purple Irish Sea Moss means that the majority of these high nutrient compounds would be lost as by-products.

Additionally, cooking the whole Purple Irish Sea Moss plant may provide added nutritional value, increasing bioavailability of nutrients found in the sea plant. Dr. Julia Lopez-Hernandez and her team of researchers at the University of Santiago de la Compostela in Galicia, Spain found that when Purple Irish Sea Moss is heated in culinary processes (steamed or boiled), the concentration of antioxidants and fat-soluble pigments increases, while the concentration of certain chromo-proteins decreases.

This vegan pumpkin bread was made with Purple Irish Sea Moss gel in place of eggs.

That same study showed that dried and rehydrated samples of Chondrus crispus do not demonstrate significant changes in nutrient concentration, which implies that our dried variety of Purple Irish Sea Moss is all ready to be shipped and used in whatever recipe your heart desires! According to our Lexington, Kentucky based customers at The Seafood Lady, a tablespoon of Purple Irish Sea Moss gel can be used to substitute for an egg in baking recipes.

We tested it out here in a seasonal pumpkin spelt bread to great gains – and great grains!

So, try out your own recipes with Chondrus crispus sometime and let us know what you think!

Thanks for reading the blog and we hope you learned something interesting about this very special and prolific sea plant that we are so happy to offer for purchase at Gulf of Maine, Inc. :-)

Iridescent Purple Irish Sea Moss growing in a Gulf of Maine tide pool.