Sodium Stearate (E470a) is a fine white powder or soft granular. The drug is a sodium salt of stearic acid, slightly bitter, odourless and tasteless, does not dissolve in water, soluble in ether or alcohol, easily soluble in most organic solvents. It named and known as Sodium Stearate.
Sodium stearate is a food additive and a synthetic substance used in the manufacture of margarines, potato chips and other similar snacks. Sodium stearate is also found in black pepper, thyme, celery seed, celery salt scones, cookies with cocoa filler and some other foods. It is made from animal or vegetable fats.
What is sodium stearate?
Sodium stearate is an organic compound with the chemical formula CHNaOCH. It is also known as sodium salt of stearic acid, where “stearic” refers to the fatty acid.
Sodium stearate is a white crystalline solid that is insoluble in water, but soluble in ethanol and diethyl ether. The decahydrate form melts at about 132°C and decomposes above 200°C. The monohydrate forms at ambient conditions and decomposes at about 200°C.
Sodium stearate is produced by the reaction of sodium hydroxide solution with vegetable oils or animal fats under high pressure; it can also be obtained by saponifying tallow or other animal fats with potassium hydroxide.
Stearic acid was first isolated by Michael Faraday in 1825 by treating stearin (a mixture of triglycerides) with dilute sulfuric acid.[1] Stearin represents about 15% of tallow and consists mainly of glyceride esters of oleic acid with long chains of carbon atoms attached to the carboxyl group (C-18). In reactions with sulfuric acid these long chains are cleaved into shorter chains containing only six carbons; this
Sodium stearate formula
Sodium stearate is a soap-like salt that is used in many different areas of the home and industry. You can find it in many different products from shampoo to laundry detergent. It is also used in some cosmetic products, like deodorant and hair conditioners.
Sodium stearate works as an emulsifier, meaning that it helps two liquids mix with each other so they don’t separate. It does this by coating the surface of one liquid with another liquid. This coats both liquids together so they stay together instead of separating.
Sodium stearate is also an ingredient in some lubricating greases, which are used on machinery to reduce friction between moving parts.
Sodium stearate soap formula
Sodium stearate soap formula is one of the most common types of soap made. This type of soap is usually made with a combination of three ingredients: sodium hydroxide, potassium hydroxide and stearic acid.
Sodium stearate soap formula has been used for hundreds of years as a way to cleanse skin and hair. The first documented use of sodium stearate soap was in ancient Egypt, where it was used as a face wash by both men and women.
Sodium stearate solubility in water
Sodium stearate is a white or colorless crystal or powder. It is insoluble in water, soluble in ethanol and ether, but the solubility of sodium stearate in water is less than 0.1g/100ml, so it’s not easy to dissolve sodium stearate in water directly. In this situation, you can use sodium carbonate solution to dissolve sodium stearate firstly and then add the solution into water.
What is sodium stearate made of?
As defined by the USP, sodium stearate consists of the following ingredients:
1. Sodium stearate
Sodium stearate is the sodium salt of stearic acid, a saturated fatty acid. It is an ingredient in soaps, detergents and cosmetics. The chemical formula for sodium stearate is CH(CH)COONa.
2. Sodium palmitate
Sodium palmitate is the sodium salt of palmitic acid, a saturated fatty acid found in various fats and oils. It is used as an emulsifier in foods, but it can also be used as a cleaning agent or preservative in other items such as cosmetics or shampoos. The chemical formula for sodium palmitate is CH(CH)COOONa.
3. Sodium salts of other fatty acids
There are many different types of these salts besides just those two mentioned above, including potassium laurate and potassium oleate among others. These provide a variety of benefits to the products they are included in (such as conditioning properties or stability), but they are all made with similar processes that start with alkaline hydrolysis (breaking down) of natural fats into their basic components: glycerol and fatty acids.
How is sodium stearate made?
For obtaining this ingredient, two manufacturing processes are generally available.
1. Direct process
Sodium stearate is produced by reacting stearic acid with sodium hydroxide. Stearic acid is derived from fats during the soap making process. The direct process involves mixing molten stearic acid with molten sodium hydroxide to produce sodium stearate:
C17H35COOH+NaOH=C17H35COONa+H2O
The reaction takes place at 200 °C in an open pan reactor. The resulting mixture is quenched in water to prevent any further reactions taking place between the sodium hydroxide solution and the remaining free fatty acids present in the product.
In some cases, triglycerides are hydrolyzed to form fatty acids before being reacted with sodium hydroxide.
2. Triglyceride hydrolysis
Sodium stearate is produced by reacting stearic acid with sodium hydroxide, which forms sodium stearate and water. Triglyceride hydrolysis is the chemical reaction that occurs when triglycerides are broken down into free fatty acids or monoglycerides and glycerol.
(C18H35O2)3C3H5 + 3 NaOH → C3H5(OH)3 + 3 C18H35O2Na
Triglyceride hydrolysis can be performed using either dry or wet catalysis. The main difference between these two methods is the temperature at which the reaction takes place. In dry catalysis, temperatures are typically high enough to cause decomposition of any excess water present in the reaction mixture. However, in wet catalysis, the reaction mixture contains excess water that serves as a catalyst for the reaction.
Where is stearic acid comes from?
Fatty acids can either be derived from edible fats and oils or from distilled food fats.
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As you can see from the data provided by EFSA, we can see:
- Together, palmitic acid and stearic acid make up most of all fatty acids, whether they come from vegetable or animal sources.
- Oils and fats from animal origin (e.g. lard and tallow) have a higher level of stearic acid than oils from vegetable origin (e.g. rapeseed oil, soybean oil, palm oil, coconut oil, sunflower oil).
Properties
Appearance
A white, creamy, flaky or semi-solid powder. A greasy feeling when touched and an odor of fat when smelt.
Solubility
The sodium and potassium alkali metal stearates are the only alkali metal stearates that dissolve in water and dissociate sodium and potassium ions after dissolving in water. Stearic acid does not.
In the presence of water, stearate ions form fatty acids and hydroxyl ions, so the resulting aqueous solution is alkaline, which forms an oil-in-water (O/W) emulsifier with a HLB value not exceeding 16. A temperature of about 70°C is the only temperature at which sodium and potassium stearate are soluble in water.
Sodium stearate and calcium stearate, the other two metallic stearates, are practically insoluble in water.
| Other names | Sodium octadecanoate
Sodium salts of fatty acids |
| CAS number | 822-16-2 |
| Chemical formula | C17H35COONa |
| Molecular weight | 306.466 |
| Melting point | 245 to 255 °C |
| Solubility | Soluble in water, insoluble in ethanol |
Structure
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The structure of sodium stearate has 18 carbons. This molecule consists of both hydrophilic (the carboxylate end, a polar end) and hydrophobic (the long non-polar hydrocarbon chain, a non-polar end). According to the structure, soap’s characteristics are explained by the non-polar tail dissolving in non-polar substances while the polar head will not dissolve in non-polar substances. In addition, the hydrophilic, ionic head is hydrophilic and disperses in hydrophilic solvents, such as water. In soap making, this property is used.
Sodium stearyl fumarate vs magnesium stearate
Sodium stearyl fumarate is an emulsifier that is used in many cosmetic and personal care products. It is derived from coconut oil and can be derived from palm oil as well. Sodium stearyl fumarate is used primarily to stabilize emulsions, provide texture to a product, and provide conditioning properties.
Magnesium stearate is a lubricant which has been used for years in the food industry. It works by reducing friction between moving parts, thereby reducing wear. Magnesium stearate is also used as an anti-caking agent, flow agent and dispersant in cosmetics and personal care products such as makeup, skin care products, hair care products, antiperspirants and deodorants.
What is sodium stearate used for?
Sodium stearate is used in a number of different industries. It is most commonly used in the food industry as an emulsifier and thickener. It can also be found in cosmetics, where it is used as a lubricant and moisturizer. It can also be used in pharmaceuticals. Sodium stearate uses including:
Food
Sodium stearate is used in many different types of foods, including baked goods, soft drinks, salad dressings, sauces and more. It helps to improve the texture of food products by reducing the amount of water required for preparation. It can also keep foods fresh longer by reducing oxidation. The following foods may contain it:
- Table-top sweeteners in tablets
- Dried herbs and spices
- Fruit (as a glazing agent)
- Nutrient (as a carrier)
Cosmetics
Sodium stearate is added to many different cosmetic products because it acts as a lubricant and moisturizer for skin and hair products. For example, sodium stearate may be added to shampoos or conditioners because it makes them easier to spread out over the scalp or hair shafts. It is used for the following purposes：
- Sodium stearate in deodorant and air fresheners: The gelling ability of this substance can help form solid sticks when combined with other materials, including propylene glycol, glycerin, and propanediol.
- Cosmetics and personal care products: skincare products, body wash products, toothpaste and so on.
Pharmaceuticals
Sodium stearate has been shown to have antimicrobial activity against several species of bacteria and fungi. The mechanism for this action has not been identified but may involve cell membrane disruption or inhibition of fatty acid synthesis or membrane transport processes. Sodium stearate has been investigated as an antimicrobial agent for use in topical applications, such as ophthalmic solutions (eye drops) but no commercial products are available at this time.
Industrial
Sodium stearate in soap
The most common use of sodium stearate is in soap making. The soap is made by combining lye and animal fat, then adding water. Sodium stearate is used to make the soap more stable and less likely to melt when exposed to heat or water.
Is Sodium Stearate Safe to Eat?
This food additive is very well tolerated, and it has been approved as safe by the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA), as well as the Joint FAO/WHO Expert Committee on Food Additives (JECFA) as well as a number of other authorities.
FDA
In compliance with accepted manufacturing practice, sodium salts of fatty acids can be employed as binder, emulsifier, and anticaking agents in foods and in food components. In addition to being used to manufacture chewing gum, it is also a safe chemical. It is safe to use sodium stearate as an anti-ticking agent in animal feeds when it is feed-grade. Among the approved fatty acids are stearic acid (C18), palmitic acid (C16), oleic acid (C18:1), lauric acid (C12), myristic acid (C14), capric acid (C8), and caprylic acid (C10).
EFSA
Sodium stearate (E470a) is an authorised food additive listed in Commission Regulation (EU) No 231/2012 as an “additives other than colours and sweeteners”.
Safety re-evaluation in 2018
As the EFSA pointed out, there was no need to establish an acceptable daily intake (ADI) for sodium salts of fatty acids (E 470a) when used as food additives, and there was no safety concern at the levels reported in 2018.
UK Food Standards Agency
The product is listed in the category of “Emulsifiers, Stabilisers, Thickeners and Gelling Agents”.
Food Standards Australia New Zealand
In Australia and New Zealand, it is an approved ingredient with the code number 470.
JECFA
Function class: food additive, anticaking agent and emulsifier.
Acceptable daily intake: In 1985, ADI set “not specific”.
What are the benefits of sodium stearate?
Sodium stearate is a fatty acid salt with a hydrophobic tail and a hydrophilic head. It is an ingredient in many personal care products and cosmetics, including soaps, shampoos, conditioners, creams, lotions and deodorant sticks. Sodium stearate is also used as an emulsifier in foods such as frozen desserts, ice cream and whipped toppings.
Sodium stearate has many benefits for the consumer. These include:
Antioxidant Properties: As an antioxidant, sodium stearate can help prevent free radical damage to skin cells and prevent premature aging of skin cells. It also helps increase skin elasticity by promoting new cell growth.
Moisturizing Properties: Sodium stearate has moisturizing properties that help keep skin hydrated, preventing drying out of the skin caused by bathing in hard water or extreme temperatures. This can lead to increased elasticity in the skin as well as reduced wrinkles and fine lines over time.
Conditioning Properties: Sodium stearate helps condition your hair by adding moisture when used in shampoos or conditioners. It also adds shine to your hair when used in styling products such as mousse or gel spray.
What are the side effects of sodium stearate?
Sodium stearate is a salt that is used as an emulsifier and thickener in foods, pharmaceuticals and cosmetics. The U.S. Food and Drug Administration does not allow sodium stearate to be added to foods but does allow it to be used in cosmetics and personal care products such as soaps, shampoos, hair conditioners and body lotions at concentrations up to 1%. Sodium stearate may also be found in some medications such as eye drops and suppositories.
Side effects of sodium stearate include:
- Irritation of the eyes or skin if it gets into these areas while being applied by someone else or during self-application; this can result in redness, burning or itching (contact dermatitis).
- Allergic reactions, including swelling of the mouth or throat (angioedema) or hives; if you experience any signs of an allergic reaction (such as wheezing), stop using the product immediately and seek medical attention.
Where to buy sodium stearate?
Sodium stearate has been approved by the U.S. Food and Drug Administration (FDA) as a food additive since 1954. It can be purchased through online retailers such as Amazon or eBay.
Frequently asked questions
Is sodium stearate baking soda?
No, sodium stearate is not baking soda.
Baking soda is a combination of sodium bicarbonate and carbon dioxide. Sodium stearate is a fatty acid. They are two different compounds with different properties.
Is sodium stearate natural?
No, Sodium stearate is a chemical compound that is used as a food additive and a detergent. It is also used in making soap and other products, such as leather and rubber.
Sodium stearate is made from vegetable oil or animal fat. The vegetable oil or animal fat is mixed with sulfuric acid or sodium hydroxide. This mixture creates sodium salts, including sodium stearate.
Is sodium stearate halal?
Yes, sodium stearate is halal.
Sodium stearate is a salt made from a combination of stearic acid and sodium hydroxide. The Muslim Council of Britain (MCB) has certified that sodium stearate can be consumed by Muslims.
Is sodium stearate kosher?
Yes, sodium stearate is a kosher additive. In order to be kosher, sodium stearate must be made from vegetable oil, and it cannot be made with animal-based fats or tallow.
Is sodium stearate gluten free?
Yes, sodium stearate is gluten free. It is a salt of stearic acid and sodium hydroxide.
Is sodium stearate vegan?
Yes, sodium stearate is vegan.
Sodium stearate is a salt that contains stearic acid, which is derived from animal fat. However, the salt is produced by neutralizing lye with vegetable oil. Sodium stearate is also found in many soaps (including natural ones), shampoos and cosmetics.
Conclusion
Sodium stearate is used in a wide variety of industries and in many types of food products. It’s found in baked goods, processed foods, chewing gum, and other products, and it has many different uses. The fact that it sounds very similar to Stearic acid may cause for some confusion; however, the two have different functions and applications. Furthermore, sodium stearate is considered safe for human consumption by the Food Standards Agency, meaning that it is low risk to human health. It may be included in small amounts in a food product; as long as this amount is within the manageable limit, it is considered safe and healthy.
