What Is Propylene Glycol Alginate (E405)? Uses, Safe, Effect

What Is Propylene Glycol Alginate (E405)? Uses, Safe, Effect


Table of Contents

Propylene Glycol Alginate (E405) is a thickener used in food products. It is made of an extract from brown seaweed or red seaweed. Propylene Glycol Alginate (E405) also has several other names, depending upon the manufacturer. These include alginic acid, propane-1,2-diol alginate, propylene glycol mono alginate, and E406.

What is propylene glycol alginate?

Propylene glycol alginate is a food additive that acts as a gelling, thickening and stabilizing agent. It is used in foods to give them texture and structure, such as ice cream and frozen desserts.

Propylene glycol alginate is commonly found in candy, chewing gum and cake mixes in the United States. It may also be used as an emulsifier for oils and fats, which are mixed together with water or other liquids to create creamy textures such as buttercream frosting for cakes or mayonnaise for sandwiches.

Propylene glycol alginate is produced by combining propylene glycol with alginic acid from seaweeds (algae). Alginic acid occurs naturally in seaweeds, where it forms long chains that bind to each other when they are put into water. The resulting substance creates a gel-like matrix that has many uses in food products.

What is propylene glycol alginate made from?

Propylene glycol alginate is made from seaweed extract. It is a thickening agent used in the food industry, most commonly in ice creams and frozen desserts.

Propylene glycol alginate is also used in skin care products, such as deodorants.

Propylene glycol alginate has been shown to have antioxidant properties that can help protect the skin from free radical damage.

What is propylene glycol alginate in food?

Propylene glycol alginate is a thickening agent used in processed foods, including ice cream, chocolate milk and salad dressings. It is made from two ingredients: propylene glycol, which is found in antifreeze and de-icing solutions; and alginate, a substance found in brown algae.

Propylene glycol alginate does not have an FDA “Generally Recognized as Safe” (GRAS) designation and has never been approved for use in food by the FDA. However, it is considered to be safe for human consumption when used at levels approved by the FDA (21 CFR 172.841). When added to food products at levels of less than 0.5% by weight of the product, propylene glycol alginate has been shown to be safe for use within its specified limits on an interim basis pending additional toxicological data (21 CFR 172.841).

How is propylene glycol alginate made of?

An alginic acid carboxylic acid group can be partially esterified with propylene oxide and alkaline as a catalyst under conditions of approximately 70 degrees Celsius to produce PGA.

It is composed of PGA, neutralized alginic acid, and free alginic acid at the end of the synthesis reaction. In order to use ester in food, the FDA requires a degree of esterification of at least 85%. A food grade of PGA depends on its viscosity and the percentage of esterification.



Fibrious, granular or powdery, almost odourless, white to yellowish-brown in color.

Other names
  • Alginic acid propylene glycol ester
  • Propane-1,2-diol alginate
  • Hydroxypropyl alginate
CAS number 9005-37-2
Chemical formula (C9H14O7)n
Molecular weight 10 000 -600 000

PGA Structure




Cold water soluble


This is a low viscosity thickener with a viscosity of 1% solution with a range of 25–500 mPas and an esterification range of 50% to 90%. With increasing esterification degree, viscosity increases as well.


The viscosity of its solution will not be affected by pH between 2 and 10. In an acidic environment, it is stable. Although it has a weak alkali resistance, it will be gradually hydrolyzed into propylene glycol and alginate ion when exposed to alkaline conditions.

What is propylene glycol alginate used for?

In the molecule of PGA, the propylene glycol group is a lipophilic end that can combine with fats, thus giving it lipophilicity. This molecule contains uronic acid, which has hydroxyl and carboxyl groups that can combine with proteins. As a result, PGA molecules contain both hydrophilic and lipophilic groups, enabling them to emulsify, stabilize, and thicken liquids. The following foods can be prepared with it:

  • Dairy products
  • Salad dressing
  • Beer
  • Beverages with acidity, sports drinks, and fruit juices
  • Frozen foods
  • Bakery
  • Jelly

Acidic Beverage

In drinks such as lactic acid drinks and fruit juice drinks, PGA is acid-stable and can be used.


Due to its good foaming and emulsifying properties, propylene glycol alginate is widely used as a beer foam stabilizer. The stabilizer PGA is also used in Corona beer, according to Wikipedia.

Salad Dressing

In salad dressings, PGA stabilizes oil and water and gives them a soft texture. It stabilizes and uniformizes the salad dressing. Due to its low fat content, low-fat salad dressings have a low viscosity because of PGA.

Ice Cream

Ice cream with PGA has improved dispersion stability for oils and fat solids. As well as improving taste and appearance, it also prevents ice cream from melting. Furthermore, PGA prevents lactose ice crystals from forming.


A thickener and stabilizer can also be added to yogurt as a thickener and stabilizer to prevent syneresis. However, they differ from PGA in several ways:

  • Vegetarians do not accept gelatin
  • At low pH, carrageenan isn’t stable in acidic dairy products
  • Pectin increases the production cost of yogurt and makes its texture hard
  • Yogurt tastes sticky and contains more calories when it contains starch

Yogurt production can benefit from PGA because it contains

  • Provides a natural texture to yogurt products,
  • Provides a smooth taste
  • Suitable for low pH environments
  • Very good dispersibility and solubility
  • During heating, the product remains stable


In addition to making bread taste better and more elastic, PGA increases its ability to absorb water. In addition, it prolongs the shelf life of bread by slowing down the aging of starch.

Fruit Juice

It is easy to separate the juice into two layers, the upper layer containing clear and transparent water and the bottom layer containing pulp precipitation. Propylene glycol alginate can improve pulp stability without separating by adding a small amount to the fruit juice.


Food fragrances can benefit from PGA, which prevents flavor loss and combines with most flavors.

Synergy with other Thickeners

As well as sodium carboxymethyl cellulose, modified starch, sodium alginate, gum arabic, and pectin, PGA has excellent synergistic properties.

Is propylene glycol alginate safe?

There is no doubt that this ingredient is safe. It has been approved for use by the FDA, EFSA, and Joint FAO/WHO Expert Committee on Food Additives (JECFA).


Here is a list of foods that may contain propylene glycol alginate as a stabilizer, emulsifier, thickener, defoaming agent, flavoring adjuvant, formulation aid, or surfactant:

  • Jams and jellies 0.4%
  • The percentage of dairy desserts, fruit and water ices, and confections and frostings is 0.5%
  • Baked goods 0.5%
  • Gelatins and puddings 0.6%
  • Condiments and relishes 0.6%
  • Cheeses 0.9%
  • Fats and oils 1.1%
  • Seasonings and flavors 1.7%


In Commission Regulation (EU) No 231/2012, propane-1,2-diol alginate (E405) is listed as an authorised food additive and categorized as “Additives other than colours and sweeteners”.

Safety Revaluation in 2018

According to the EFSA, at the ADI of 55 mg/kg bw per day, based on the ADI of propylene glycol (E1520) of 25 mg/kg bw per day, there are no safety concerns regarding E405 at the ADI of 55 mg/kg bw per day.

Approved uses

There is a possibility that the following foods may contain propylene glycol alginate at a maximum concentration of 100mg/kg to 10000mg/kg:

  • Edible ices based on fats and oils
  • Sugar confectionery and fruit preparations
  • Gum for chewing
  • Fillings, coatings, and decorations
  • Baking wares of fine quality
  • A sauce
  • Infant formulae and dietary foods for special medical purposes
  • Dietary foods for medical purposes or weight loss
  • Beverages with flavours, such as beer, malt beverages, cider, and perry
  • Fermented grape must-based drinks, emulsified liqueurs
  • Snacks made from cereals and potatoes

UK Food Standards Agency

Categorized in “Others”

Food Standards Australia New Zealand

In Australia and New Zealand, this ingredient has the code number 405 indicating it is a registered ingredient.


Classification: food additives, emulsifiers, thickeners, stabilizers.

Group ADI of “70 mg/kg bw” was established in 1993.

What are the propylene glycol alginate side effects?

Propylene glycol alginate is an antacid drug that relieves heartburn and acid indigestion. It works by reducing the amount of acid your stomach produces.

Propylene Glycol Alginate Side Effects

Propylene glycol alginate can cause side effects. The most common side effects are nausea, constipation, diarrhea, and abdominal pain. These side effects usually go away after you take the medication for a while.

More serious side effects include:

Allergic reaction. Propylene glycol alginate is known to cause allergic reactions in some people. A rash may develop on your skin after taking this medication for a few days. Call your doctor if you have any swelling or itching of the face or mouth area, hives, shortness of breath, wheezing, dizziness, or paleness. These are signs that you may be having an allergic reaction to propylene glycol alginate.

Frequently Asked Questions

Is propylene glycol alginate bad for you?

Propylene glycol alginate is considered safe for human consumption by the FDA, which has approved it for use in food products. However, studies have shown that propylene glycol alginate can cause irritation when used on the skin and should not be ingested.

Propylene glycol alginate can also cause allergic reactions in some people, so if you have sensitive skin or have ever had an allergic reaction to another chemical in your skincare regimen, make sure you patch test before using this product!

Propylene glycol alginate fda approved?

Yes.  Propylene glycol alginate is a food additive that has been approved by the FDA.

How to find propylene glycol alginate manufacturer?

If you are looking for a reputable propylene glycol alginate manufacturer, you will want to look for a company that has been in the business of manufacturing this type of material for years. The best way to find such a company is to ask around your local area. A good place to start is by asking your local pharmacist or doctor if they know of any propylene glycol alginate manufacturers in the area.

Another way to find propylene glycol alginate manufacturers is by doing an internet search for propylene glycol alginate manufacturers near me. You may also want to look at other industries that use this product as well as the products themselves. If you know what type of product you need, then it should be easier for you to find a company that specializes in making them.

Propylene glycol alginate is halal?

Yes, The PGA has been certified as Halal by the Islamic Law and meets the Halal requirements. We can also find some manufacturers who are MUI Halal-certified.

Propylene glycol alginate is vegan?

As a vegan product, it is not manufactured with animal products. Vegetarians can add PGA to their diet.

Propylene glycol alginate in food scares customers because they associate it with propylene glycol which is used in antifreeze, and mistake it for other harmful chemicals. As a solvent, propylene glycol alginate is used as an antifreeze ingredient to keep water from freezing. It is a safe food additive.


Propylene Glycol Alginate E405 is a food additive and preservative commonly used in various processed foods and bakery products. It is believed to have the ability to inhibit mold growth, which is the primary reason why the additive is utilized by food producers throughout the world to prevent spoilage.

if you have any thought about propylene glycol alginate please leave your comments.

Sophie Feng

Sophie Feng

Sophie Feng is the author of gradechemical.com, she is the co-founder of the grade chemical network. She has been in grade chemical company since 2017, with a working knowledge of food chemical .

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