Carrageenan
What it does
Thickener/stabiliser.
How it's made
Extracted from red seaweed.
Carrageenan is a natural thickener, gelling agent and stabiliser extracted from red seaweeds, used very widely in dairy products, plant milks, desserts, processed meats and sauces. Different types produce anything from a soft, pourable thickening to a firm gel, and it is especially good at working with milk proteins.
It is obtained from red seaweeds (such as Chondrus crispus — Irish moss — and Kappaphycus). The seaweed is treated with a hot alkaline solution, which dissolves out the carrageenan; the extract is filtered and then the carrageenan is recovered, either by precipitating it with alcohol or by gelling it with potassium and pressing out water, before drying.
The purified carrageenan is milled into a powder and blended to standard gelling strengths. Its ability to interact with the proteins in milk is why it is so common in dairy and plant-based drinks (keeping them smooth and stopping separation); it is seaweed-derived and suitable for vegetarians and vegans.
Possible reactions
Some studies suggest gut inflammation in susceptible people; debated.