Sodium Citrate

Introduction

Sodium citrate is a type of salt that can be found in many types of foods, particularly those that are citrus-based. It is also known as trisodium citrate and has the chemical formula of Na3C6H5O7. It is primarily used as a food additive and preservative, but it also has medical and industrial applications.

Chemical Properties

Sodium citrate is a white, crystalline powder that is slightly deliquescent in moist air. It is highly soluble in water and practically insoluble in ethanol. The compound is a conjugate base of a citric acid, and it has a sour taste. When heated to decomposition, it emits toxic fumes of sodium oxide.

Production

Sodium citrate is produced by neutralizing citric acid with sodium hydroxide. This reaction produces sodium citrate and water. The sodium citrate is then purified and crystallized.

Food Industry

In the food industry, sodium citrate is commonly used as a flavor or preservative. It gives a pleasant sour taste to foods and beverages and enhances the effect of other antioxidants. It is also used as an emulsifier for oils in the production of cheese and as a buffer to control the acidity of food and drink products.

Medical Uses

In medicine, sodium citrate is used as an anticoagulant, an alkalizer, and a urine alkanizer. It is also used in a test for the diagnosis of gastrointestinal disorders. In addition, it is used as a buffer in pharmaceutical formulations.

Industrial Uses

Sodium citrate is used in the industrial sector as a buffer, a sequestering agent, and a builder in soaps and detergents. It is also used in the photography industry in the preparation of developer solutions.

Safety

Sodium citrate is generally recognized as safe when used in normal quantities. However, excessive consumption can lead to an imbalance of electrolytes in the body, causing muscle cramps or weakness.

Environmental Impact

Sodium citrate is biodegradable and poses no major threat to the environment. However, like all salts, it can contribute to the salinization of water bodies if released in large quantities.