Gellan gum, an ingredient made from fermentation by Sphingomonas elodea, is commonly used as a gelling agent, stabilizer and thickener in food and beverage. The European food additive number for it is E418. It is a soluble fiber with two types, high acyl and low acyl, and follows the different uses.
What is gellan gum?
By EFSA’s definition, gellan gum is a high-molecular-weight extracellular polysaccharide produced from the fermentation of a carbohydrate by strains of Pseudomonas elodea. (1)
It is composed of tetrasaccharide repeat units, each containing two D-glucose units, one D-glucuronic acid and one L-rhamnose. (2)
What is it made of?
It is composed of polysaccharide, proteinaceous material (by nitrogen content, %N = 0-3.0%), and polyhydroxybutyrate (PHB) up to 25 wt%.
What is it made from?
Like Xanthan gum, gellan gum is also a bacterial polysaccharide which is produced by strains of Pseudomonas elodea.
Now this strain is also named as Sphingomonas elodea or ATCC 31461. It is the only strain that can be used for production.
Manufacturing flow can be divided into two main processes, fermentation process and then through the purified process.
Culture the ATCC 31461 bacterial strain in the medium with a carbon source (common sugars), nitrogen sources and mineral salts.
The purification process is different based on the various types of gellan gum.
- High acylated form: direct recovery from broth by alcohol precipitation.
- Low acylated form: treat the broth with alkali and then with alcohol precipitation.
- Clariﬁed form: filter low acylated gellan gum to remove cell residues and other insoluble components.
Two types of gellan gum
Gellan gum is divided into two types, high acyl and low acyl form by the degree/percent of substitution by O-acyl groups.
1. High acyl gellan gum
It is also called HA Gellan gum. Two acyl substituents acetate at C6 and glycerate at C2 on the ﬁrst glucose unit of the repeating unit of tetrasaccharide, and on average, there is one glycerate per repeat and one acetate per every two repeats.
With the chemical structure follows:
2. Low acyl gellan gum
It is also called LA Gellan gum. It is partly deacylated or fully deacylated. Its common form is the fully deacylated one, with no detectable acyl groups, also called deacetylated gellan gum.
With the chemical structure follows:
The following are the Specification difference among the three types.
|Specification||High Acyl||Low Acyl||Deacylated|
|Degree of acylation||> 50%||≤ 50%||< 1%|
|Total acyl content (wt%)||> 7.35 wt%||≤ 7.35 wt%||< 0.15%|
|Molecular weight||1–2 *10^6||2–3 *10^5|
An off-white powder.
It is the water-soluble anionic polysaccharide, fully soluble in water once heated, forming a viscous solution; insoluble in ethanol.
Low acyl VS high acyl gelation
The easiest way to form both gels is to cool hot solutions.
The comparison as follows:
Low Acyl Gels:
- It forms gels with cations, e.g. calcium(Ca2+), magnesium (Mg2+), sodium (Na+), and potassium (K+), as well as acid (H+) and the presence of these cations increases the gel strength and brittleness.
- It forms gels itself at concentrations as low as 0.05%. (Handbook of hydrocolloids, Edited by G. O. Phillips and P. A. Williams, 2000)
- Not thermally reversible
High Acyl Gels:
- The gels and the properties are less dependent on the concentration of ions in solution.
- The needed concentration to form gel itself is around 0.2%. (Handbook of hydrocolloids, Edited by G. O. Phillips and P. A. Williams, 2000)
- Thermally reversible.
The gels show very different textures (related with Acyl content), HA forms soft, elastic and non-brittle gels whereas LA forms ﬁrm, non-elastic and brittle gels.
Generally, the gel property as follows:
- Heat stable: The gels are stable at high temperature as its solution is heated to 90–95°C for 10–15 min in the production process.
- PH stable: stable in pH range between 3.5 and 8.
- Synergistic with konjac glucomannan.
What are the application of gellan gum?
Gellan gum is a multi-functional hydrocolloid used as a gelling, texturizing, stabilizing, suspending, film-forming and structuring agent in food, beverage, personal care applications and pharmaceuticals.
Commonly the usage level ranges from 0.1% to 1%. And usually, we can find it in plant-based drinks, fruit/flavoured still drinks, nectars, pastilles, gums, jellies & chews, meal replacements, desserts, and flavoured milk.
Water-based dessert jellies are commonly brittleness, cohesiveness, elastic, creamy, sticky, firm, wobbling, syneresis and easy demoulding.
Gellan gum functions as a gelling, texturizing, stabilizing, suspending, film-forming and structuring agent in water desserts & dessert Gels.
LA or blends of HA and LA can be used to provide dessert jellies with a variety of textures.
How to make fruit juice jelly with LA gellan gum and gelatin?
- Prepare ingredients: Water 500.0g (82.6%), Sugar 90.0g, (15.0%), Citric acid anhydrous 2.3g (0.38%), Tri sodium citrate dihydrate 1.6g, (0.26%), LA gellan gum, 0.35g (0.06%), Gelatin 10.2g (1.7%), Color and flavor as required.
- Blend all the dry ingredients.
- Heat the water to boil and dissolve the blended ingredients into the boiling water by stirring for 1-2 minutes.
- Deposit and chill.
(Handbook of hydrocolloids, Edited by G. O. Phillips and P. A. Williams, 2000)
Gellan gum can be used as a suspension agent (for example, suspend jelly beads and form a smooth fluid gel), stabilizer and mouthfeel creator in juices, juice drinks, dairy alternative & plant-based beverages. (3)
Drinking yogurts are more popular due to its health benefits. Gellan gum can control syneresis, provide suspension, create body & texture, and improve mouthfeel in yogurts.
Plant-based milk containing it to help plant protein suspended in the milk, such as almond milk and soy milk, some types are flavored.
Gellan gum can be applied in a range of confectionery products, which are rich in sugar, like gummy and chewy confections, marshmallows, jellies, pastes, candies and so on.
Combinations of sugars (such as sucrose, glucose, fructose and corn syrups) with the hydrocolloid produces desirable jelly textures, gel clarity, flavour release and so on.
High and low acyl gellan gum can be used in bakery mixes; bread, muffins and cakes; frozen dough icings, frostings and glazes. (4)
Per “European Commission database for information on cosmetic substances and ingredients”, it can function as a film forming and viscosity controlling agents in cosmetic and personal care products. (5)
Gellan Gum was initially an alternative for agar in solid culture media for the growth of various microorganisms (6). It is used for plant tissue and cell culture with the advantage of producing a high transparent gel than agar. (7)
Is gellan gum safe to eat?
Yes, it almost has no side effects and the safety has been approved by the U.S. Food and Drug Administration (FDA) and European Food Safety Authority (EFSA), as well as the Joint FAO/WHO Expert Committee on Food Additives (JECFA).
The FDA claimed the food additive gellan gum may be safely used in food as a stabilizer and thickener. (8)
Gellan Gum (E 418) is authorised as a food additive in the European Union (EU) in accordance with Annex II and Annex III to Regulation (EC) No 1333/2008 on food additives and categorized as “additives other than colours and sweeteners” (9)
Re-evaluation the safety in 2018
After the study on genotoxicity, carcinogenicity, reproductive and developmental toxicity, EFSA concluded that “there is no need for a numerical acceptable daily intake (ADI) for gellan gum (E 418), and that there is no safety concern at the reﬁned exposure assessment for the reported uses and use levels of gellan gum (E 418) as a food additive.” (10)
Its approved applications are listed separately with E418 in 4 food categories and in Group I in 67 food categories where the uses is quantum satis (QS).
Following foods may contain it:
- Jam, jellies and marmalades and sweetened chestnut purée
- Fruit or vegetable spreads
- Table-top sweeteners
Gellan gum (E 418) is also authorised used as a carrier in food enzymes and in all nutrients except nutrients intended to be used in foodstuffs for infants and young children in Annex III of Regulation (EC) No 1333/2008. (11)
UK Food Standards Agency
Categorized as an emulsifier, stabiliser, thickener and gelling agent. (12)
Food Standards Australia New Zealand
It is an approved ingredient in Australia and New Zealand with the code number 418. (13)
Function Class: food additives, gelling agent, stabilizer, thickener. (14)
ADI: ADI not specified set since 1990. (15)
What are the possible side effects?
It is common that sometimes consumers have questions whether gellan gum is bad for our health and what are the side effects. It is generally safe and there were few health risks reported.
EFSA did not find allergic reactions in humans after oral exposure to gellan gum.
Is it safe for pregnant?
There were no adverse effects from EFSA’s study of reproductive and developmental toxicity on rats up to 5% in the diet.
Frequently Asked Questions
What Does Gellan Gum do in Food?
It is added to foods to modify thickness or enhance texture.
Is Gellan Gum Natural?
From information of CPKelco, the top manufacturer, that the composition and structure of native gellan gum (high acyl) produced by fermentation is identical to the naturally occurring polysaccharide formed by Sphingomonas elodea on plants of Lily pad varieties.
The commercial low acyl form is not natural as it is obtained by treating with alkali.
Is Gellan Gum Halal?
Yes, it is generally recognised as halal. And we can find several suppliers certificated with MUI halal.
Is Gellan Gum Kosher?
Yes, it is kosher pareve. It has met all the “kashruth” requirements and can be certified as kosher.
Is Gellan Gum Gluten free?
Yes, it is gluten free according to FDA’s gluten free difinition that gellan gum does not contain wheat, rye, barley, or crossbreeds of these grains.
Is Gellan Gum Vegan?
Yes, it is vegan. Raw materials and the manufacturing process without the use of animal matter or products derived from animal origin. So it is suitable for vegetarian foods and beverages.
Now you may have a good knowledge of the food additive – Gellan gum E418, from its production; two types: high acyl and low acyl and their comparison; properties, uses; approved safety, possible side effects and some FAQs such as is it vegan, gluten free, synthetic or natural.
EFSA indicated that gellan gum was found in 1,194 food products between January 2013 and January 2018, published on Mintel’s GNPD. What kinds of food packaging have you found this ingredient in? Let me know in the comments.