Sodium Citrate Е 331

Property Descriptions

Sodium citrate E331, English Sodium citrate, is the sodium salt of citric acid. From a chemical point of view, this substance has several modifications, but to date, sodium citrate, two-anhydrous, three-substituted, with the index E 311 (iii) and the chemical formula Na3C6H5O7 x 2H2O, has gained predominant industrial distribution. It is this product that experts in the food and related industries have in mind when they talk about sodium citrate.

It is an odorless white crystalline powder with a slightly salty – bitter taste. Sodium citrate is easily soluble in water, slightly soluble in alcohol. Non-flammable, non-explosive, non-toxic, does not irritate the skin, however, if inhaled in the form of dust, it may irritate the upper respiratory tract.

On an industrial scale, it is obtained by neutralizing citric acid with an equivalent amount of caustic soda.

Technological recommendations

Sodium citrate (sodium citric acid) is used in the food industry as an acidity regulator, complexing agent, dispersing agent, buffering and flavoring agent, emulsifier, melting salt. It is used in the production of marmalade, marshmallows, souffles, concentrated and powdered milk, processed cheeses, yoghurts, soft drinks and baby food. It is widely used in pharmaceuticals and medicine, in particular, as a preservative of blood and other protein substances, and is also used as a synergist of ascorbic acid.

Recently, sodium citrate has been increasingly used in the production of liquid and powdered detergents, shampoos, creams and other cosmetics.

The use of sodium citrate in confectionery production

Sodium citrate is used as a buffer salt in the production of jelly products, pectin gels and marmalade on pectin. It is also added to fruit puree before the introduction of sugar in order to slow down the formation of jelly, which occurs very quickly when pectin interacts with sugar. When citric acid and sodium citrate are added together to the technological mass, a buffer system is formed that prevents the inactivating effect of traces of metals contained in raw materials and auxiliary materials.

Sodium citrate in an amount of up to 10 kg per ton (usually 3-4 kg / ton) is added to the technological mass to increase the pH in order to prevent its premature gelling. This increase in pH is compensated by the subsequent addition of acid. The higher the concentration of sodium citrate, the lower the temperature and the longer the gelling time. Too high a dosage can negatively affect the taste and strength of the gel.

Sodium citrate has the property of stimulating foaming and maintaining the mechanical stability of foam, so it is used in the preparation of "whipped" creams, marshmallows, pastilles.

The use of sodium citrate in dairy production

Sodium citrate is used in the production of pasteurized, sterilized milk, fermented milk products, canned milk, where a more or less prolonged operation of heating milk is required. To restore the salt (ionic) equilibrium necessary for the thermal stability of the milk being heated, salt stabilizers binding calcium ions are added to it. One of the most effective stabilizer salts is sodium citrate. It is used in the form of a 10-25% solution, which is added to a specific batch of milk before heat treatment so that the concentration of sodium citrate is 0.05-0.4%. Sodium citrate is included in the list of raw materials used in GOST 718 "Canned milk. Cocoa with condensed milk and sugar. Technical specifications", GOST 1923 "Canned milk. Condensed milk sterilized in cans. Technical specifications", GOST 2903 "Condensed whole milk with sugar. Technical conditions".

In the production of ice cream, sodium citrate is used as a stabilizer and emulsifier.

The use of sodium citrate in the production of processed cheeses

Sodium citrate is used as a melting salt in the production of processed cheeses. Heat treatment of cheese is possible only through the intermediate formation of casein sol. The calcium-casein gel available in the feedstock, thanks to the melting salts, turns into liquid sodium-casein sol. If the cheese is heated without emulsifying salts, it does not melt, but shrinks, turning into a rubber-like mass, and separates oil and water. If, with stirring, 2-3% of the melting salt is added in the form of an aqueous solution, the components are sintered into a homogeneous dough. Sodium citrate gives the processed cheese a pleasant slightly salty taste and a moderately dense, rather elastic consistency. Increased active acidity creates unfavorable conditions for the vital activity of gas-forming microorganisms, as a result of which processed cheese with the use of this salt is more resistant during storage.

The use of sodium citrate in the production of detergents

In recent years, the need for sodium citrate has increased dramatically due to the steady global trend of partial or complete replacement of the active additive in the composition of synthetic detergents (SMS) — sodium tripolyphosphate, the ingress of which into reservoirs sharply worsens their ecological condition, makes them unsuitable for drinking water intake and reduces fish stocks. Due to the tightening of environmental standards, the use of tripolyphosphates in detergents has been legally restricted in industrialized countries. They are successfully replaced with sodium citrate in a concentration 3 times less than tripolyphosphates without reducing the washing ability of SMS.