Calcium Salts

Function

Calcium is a mineral salt. In molecular gastronomy, calcium salts are involved in the basic spherification or reverse-spherification processes in reaction with sodium alginate. Sodium alginate indeed needs a source of calcium to form a gel.

Origin

Calcium is a mineral salt that occurs naturally in many foods. Some of the foods richest in calcium include dairy products, some fish such as sardines, beans and watercress. The main calcium salts used in molecular gastronomy are calcium lactate, calcium chloride and calcium gluconate. Mixtures of gluconate and calcium lactate can also be found under the name of calcium gluconolactate.

Calcium chloride is obtained as a byproduct of the manufacturing of sodium carbonate. The “Solvay” process is the most common manufacturing method used to produce sodium carbonate and calcium chloride. From a salt, sodium chloride, and calcium carbonate, the main component of limestone and chalk, a share of sodium carbonate on the one hand and calcium chloride on the other are obtained.

Sodium carbonate is subsequently used in the industries of soap, glass, paper and textiles. It is also used for cooking, in a refined form called baking soda.

Calcium lactate is a salt derived from lactic acid. Lactic acid is produced by fermentation, that is to say by the action of micro-organisms in the absence of oxygen. Thus, the mitochondria of human muscles, for example, produce lactic acid when oxygen supply by blood is not sufficient during intense efforts.

Lactic acid is also found naturally in fermented foods like cheese, wine and sauerkraut. The bacteria responsible for fermentation is lactobacillus, hence the name of the products of this fermentation. The commercial production of lactic acid to extract calcium lactate is achieved by bacterial fermentation of various plant sugars like starch, molasses or beet sugar.

Calcium lactate is the salt of lactic acid. It is obtained by the treatment of lactic acid with a base in the presence of calcium ions. Calcium carbonate can be used to provide the calcium ions.

Since calcium lactate comes from the fermentation of plant sugars, it is non-allergenic for people with allergies to lactose. The word lactate refers to the lactobacillus responsible for fermentation from which it is derived, and not anything to do with lactose.

Calcium gluconate is a calcium salt derived from gluconic acid, treated with a base in combination with calcium ions by a process similar to that of lactic acid. Calcium gluconate is only used in the kitchen once it has been mixed with calcium lactate. The mixture is called calcium gluconolactate.

Industry applications

Industrially-produced calcium chloride is used, for example, as road salt or to accelerate the setting of concrete.

Calcium lactate, for its part, is mainly used in food. For example, it can be used to regulate the acidity of certain foods in order to influence the development of essential bacteria found there. Thus it improves the taste and texture of these foods. It can enter into the composition of baking powders in bakery products. It provides food for yeast in breads and beer. It is a firming agent in processed products, like cut fruits and vegetables as well as processed fish whose texture might otherwise be degraded by heat. Finally, it can ensure the firmness of the curd in some cheeses.

Calcium lactate, for its part, is mainly used in food. For example, it can be used to regulate the acidity of certain foods in order to influence the development of essential bacteria found there. Thus it improves the taste and texture of these foods. It can enter into the composition of baking powders in bakery products. It provides food for yeast in breads and beer. It is a firming agent in processed products like cut fruits and vegetables as well as processed fish whose texture might otherwise be degraded by heat. Finally, it can ensure the firmness of the curd in some cheeses.

Creative cooking applications

In creative cuisine, calcium salts are involved in the basic spherification or reverse spherification processes in reaction with sodium alginate. Calcium has indeed the property of associating with sodium alginate to form a gel.

Tips and tricks

Calcium lactate is preferred to calcium chloride as a source of calcium during spherification. These two salts usually prove to be very effective but calcium chloride usually leaves a bitter taste to the spherified food, often even after rinsing.