Sodium stearoyl lactate and calcium stearoyl lactate (stearoyl-2-lactylates) are organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

s used as a food additive

Food additive

Food additives are substances added to food to preserve flavor or enhance its taste and appearance.Some additives have been used for centuries; for example, preserving food by pickling , salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines...

s (E number

E number

E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...

 E481) in the List of food additives, Codex Alimentarius.

They are produced by first esterifying lactic acid

Lactic acid

Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...

 to produce lactylic acid, performing a second esterification with stearic acid

Stearic acid

Stearic acid is the saturated fatty acid with an 18 carbon chain and has the IUPAC name octadecanoic acid. It is a waxy solid, and its chemical formula is CH316CO2H. Its name comes from the Greek word στέαρ "stéatos", which means tallow. The salts and esters of stearic acid are called stearates...

, and then reacting the result with sodium hydroxide or calcium hydroxide

Calcium hydroxide

Calcium hydroxide, traditionally called slaked lime, is an inorganic compound with the chemical formula Ca2. It is a colourless crystal or white powder and is obtained when calcium oxide is mixed, or "slaked" with water. It has many names including hydrated lime, builders lime, slack lime, cal, or...

 to make the sodium

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

 or calcium

Calcium

Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

 salt. These salts are used as emulsifiers in processed foods.

Replacing the lactic acid with fumaric acid

Fumaric acid

Fumaric acid or trans-butenedioic acid is the chemical compound with the formula HO2CCH=CHCO2H. This white crystalline compound is one of two isomeric unsaturated dicarboxylic acids, the other being maleic acid. In fumaric acid the carboxylic acid groups are trans and in maleic acid they are cis...

 gives sodium stearoyl fumarate, a compound with similar uses.

The commercially available food additive is not composed of chemically pure stearoyl-2-lactylate. Rather, the lactic acid esterification produces a variety of polylactyls (typically numbering from one to three lactyl groups), while the chain length of the acyl fatty acid may also vary from 14 to 22 carbons, thus including palmitic and arachidic acid. Pure stearoyl-2-lactylates can be produced through an intermediate benzyl

Benzyl

In organic chemistry, benzyl is the term used to describe the substituent or molecular fragment possessing the structure C6H5CH2-. Benzyl features a benzene ring attached to a CH2 group.-Nomenclature:...

 ether

Ether

Ethers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...

 derivative.

Applications

Sodium stearoyl-2-lactylate is an emulsifier with a very high hydrophilic-lipophilic balance (HLB) and is therefore an excellent emulsifier for fat-in-water emulsions. It also functions as a humectant. It finds widespread application in baked goods, liqueurs, cereals, chewing gum, desserts, and powdered beverage mixes. Stearoyl-2-lactylates are found in the majority of manufactured bread

Bread

Bread is a staple food prepared by cooking a dough of flour and water and often additional ingredients. Doughs are usually baked, but in some cuisines breads are steamed , fried , or baked on an unoiled frying pan . It may be leavened or unleavened...

s, bun

Bun

A bun is a small, usually sweet, bread. Commonly they are hand-sized or smaller, domed in shape, with a flat bottom. A bun can also be a savory bread roll similar to a bap or barmcake....

s, wraps and tortilla

Tortilla

In Mexico and Central America, a tortilla is a type of thin, unleavened flat bread, made from finely ground maize...

s, and many similar bread-based products.
Because of its efficiency as an emulsifier, it is possible to use less of it than other similar additives; for example, it can be used in quantities only a tenth as large as soya-based emulsifiers.

Health and safety

Current applications are generally not restricted for health and safety reasons with regards to traditional uses of this emulsifier. Dietary studies in rats and dogs found no effect when this additive constituted less than 2.5% of the diet. The approximate was found to be 30 g/kg for rats - which would correspond to an intake of nearly 2 kilograms for an adult man.

In the United States, sodium stearoyl-2-lactylate is approved for use in foods as described in FDA 21CFR 172.846. Maximum usage levels of 0.5% based on flour in the U.S. and 0.375% in Canada.