Sodium Alginate 100g
Sodium alginate is the sodium salt of alginic acid which is a polysaccharide that is extracted from the cell walls of a type of brown algae that lives in marine environments in the Northern Hemisphere. It is hydrophilic and forms a firm gel when it’s mixed with water and it is used in a variety of products from sweets to screen printing.
The alginate is extracted from the seaweed by breaking the weed into small pieces and heating it up while combining it with an alkali, usually sodium carbonate. Over a couple of hours, the alginate within the seaweed dissolves into a thick sludge of sodium alginate that contains the non-soluble cellulose that needs to be filtered out. Once all the residue has been removed, the remaining paste is ground into powder.
It has several medical uses, including as a means to prevent and treat acid reflux and it is a key ingredient in a number of over the counter reflux medications. It is also used for making medical impressions for different body parts as they are needed for dentistry and prosthetics. Other alginates are used in dressings to promote faster healing and reduce pain on removal.
Sodium alginate is used in tablets to help ensure they disintegrate at the optimal moment. It is so versatile that bioengineering research suggests that hydrogels made using sodium alginate may be able to stimulate brain tissue into regenerating.
Sodium alginate in food
Sodium alginate is a very effective thickening agent and it has a number of uses in foods. It absorbs water quickly and is often used to bulk up foods such as slimming aids. It is used in commercial food production to thicken sauces and jellies and to impart a smooth and consistent texture to ice cream. It is often combined with protein flours to make meat substitutes.
Sodium alginate is also used extensively in molecular gastronomy as it is one of the key components of the processes of spherification and reverse spherification. It forms a gel instantly when exposed to calcium, meaning you can make firm gel beads out of any liquid you choose. From fruit pearls to go in your boba tea to savoury caviars that make an eye-catching addition to any dish, this process is easy to master but incredibly effective.
You can adjust the amount of sodium alginate to find the perfect texture for your gels and they will be heat resistant so will not melt if you serve them in hot drinks or in a hot meal. This makes them a popular choice for savoury dishes as they combine interesting texture with intense flavour to make an interesting addition to any dish.
Beer brewers use sodium alginate to give their beer a better head, indeed tests show that people perceive beer to be better quality when it has a lasting foam on top of it. Adding alginates to beer stabilises the bubbles in the foam making it last for longer and improves the beer’s mouthfeel.
Sodium alginate is vegan and gluten free, so it can be used in any recipe that requires a thickening or gelling agent from soups and stews to gravies and sauces. It is widely used as a texture improver because it can be adjusted to provide the level of jellification required for the optimal consistency. It works as a thickening agent and an emulsifier and is used in milk drinks and salad dressings for that reason, so it’s a handy ingredient to have on hand whatever you are cooking.