Gellan Gum in Plant-Based Milk: Stabilization, Protein Interaction and Mouthfeel

🌱 Plant-based milk looks simple in the package, but keeping it stable during processing and storage can be surprisingly difficult.

Soy, pea, almond, oat and other plant-based milks contain combinations of proteins, oils, minerals, starches and insoluble particles. These components do not always remain evenly dispersed. During storage, some products develop sediment, creaming, phase separation or changes in mouthfeel.

This is where hydrocolloids such as gellan gum can become useful.

Rather than simply making the beverage thicker, gellan gum can create a weak three-dimensional structure in the continuous phase that helps keep dispersed components in place.

🥛 Why Is Plant-Based Milk Difficult to Stabilize?

A typical plant-based milk contains several components that behave differently:

Component	Possible stability problem
Plant proteins	Aggregation or sedimentation
Vegetable oils	Creaming or separation
Minerals	Sedimentation or interactions with proteins
Insoluble plant particles	Settling
Starch or fiber	Viscosity changes or phase separation
Water	Serum separation

Heat processing can make the problem more complicated.

Plant proteins can unfold during heating, exposing parts of their structure that encourage protein-protein interactions. If the resulting particles aggregate, the beverage may become less stable during storage. Homogenization and formulation therefore work together with stabilizers to control the final particle structure.

This means that a successful plant-based milk formulation is not simply about adding more stabilizer.

It is about controlling the interaction between protein, oil, water, minerals and hydrocolloids.

🔬 What Does Gellan Gum Actually Do?

Gellan gum is an anionic microbial polysaccharide that can form a weak gel or fluid-gel structure at relatively low concentrations.

In plant-based milk, this structure can help reduce the movement of suspended particles.

Instead of relying entirely on viscosity, the formulation can use a weak internal network to provide additional suspension support.

This is particularly useful when the target product should still feel like milk rather than like a thickened beverage.

The goal is usually:

Enough structure to improve stability → but not so much structure that the drink feels heavy or gummy.

Research on soymilk has found that gellan gum can reduce precipitation during storage. In one study, gellan was among the hydrocolloids that significantly reduced precipitation, with 0.03% gellan reducing precipitation after 40 days compared with the control.

🧬 Gellan Gum and Plant Proteins

One of the more interesting areas of research is the interaction between gellan gum and plant proteins.

Plant proteins are not simply passive particles floating in water. Their surface charge, structure and interaction with other ingredients can change with pH, temperature and processing conditions.

Gellan gum can interact with these protein-containing systems through electrostatic and steric effects, while also changing the physical structure of the continuous phase.

A 2024 study on model pea milk compared gellan gum with guar gum. The researchers found that gellan gum performed better than guar gum in supporting long-term emulsion stability. The authors associated this with differences in interfacial behavior and the thicker adsorbed interfacial layer produced in the gellan-containing system.

Interestingly, the study also found that 0.1% gellan gum-containing model pea milks remained stable at 4°C for 28 days.

This illustrates an important point:

Gellan gum does not simply work by increasing viscosity. Its interaction with the protein-oil-water system also matters.

⚗️ What Happens During Heating?

Heat treatment is unavoidable in many commercial plant-based milk processes.

Pasteurization or UHT processing is used to improve microbiological safety and shelf life, but heating can also change protein structure and particle interactions.

For this reason, a stabilizer that works well before heating does not necessarily behave exactly the same way after heating.

The sequence of:

hydration → mixing → homogenization → heat treatment → cooling → storage

can therefore influence the final performance of gellan gum.

Recent research on plant-based milk analogues has also shown that polysaccharides and pasteurization can significantly alter colloidal interactions and stability. High-acyl gellan gum was particularly effective in improving stability after thermal treatment in the studied model systems.

🌡️ HA vs LA Gellan Gum in Plant-Based Milk

The choice between high-acyl and low-acyl gellan gum is important.

High-Acyl Gellan Gum

HA gellan gum generally forms softer and more elastic gels.

This can make it attractive for plant-based milk where the desired texture is:

• Smooth
• Creamy
• Soft
• Milk-like
• Not overly firm

HA gellan can provide suspension support without necessarily creating the brittle gel structure associated with low-acyl gellan.

Low-Acyl Gellan Gum

LA gellan gum forms firmer and more brittle gels.

This property can be useful in applications where a stronger structure is required, but it needs to be carefully controlled in a milk-style beverage.

Too much structure can change the drinking experience.

For many plant-based milk formulations, therefore, the question is not simply:

“Which gellan is stronger?”

It is:

“Which gellan produces the right balance between stability and mouthfeel?”

👅 Stability Is Not Enough — Mouthfeel Matters

A plant-based milk can be physically stable and still fail as a commercial product if the texture is unpleasant.

Consumers generally expect milk alternatives to pour easily and feel smooth in the mouth.

A formulation that is excessively viscous may create:

• A heavy mouthfeel
• Poor drinkability
• A gummy sensation
• Excessive coating in the mouth
• Poor performance in coffee applications

This is why low-dose gellan systems can be interesting.

The objective is not to create a thick beverage.

The objective is to create just enough internal structure to control particle movement.

This is also why rheology becomes useful during formulation development. Measuring viscosity at only one shear rate may not tell the whole story. Flow behavior under stirring, pouring and drinking can be quite different.

🥄 Gellan Gum and Protein Sedimentation

Sedimentation is one of the most visible problems in plant-based milk.

If protein particles or other insoluble material are sufficiently dense, gravity gradually moves them toward the bottom of the package.

There are two basic ways to slow this process:

1. Increase the viscosity of the liquid.
2. Create a weak structure that limits particle movement.

The second approach is particularly interesting for gellan gum.

A weak gellan network can act almost like a supporting framework throughout the liquid phase.

The particles do not necessarily need to be surrounded by a highly viscous liquid. Instead, their movement can be restricted by the structure of the continuous phase.

This is one reason gellan gum can be useful at relatively low concentrations.

🧪 What About Calcium?

Calcium is especially important in some plant-based milk formulations.

Calcium may be added for nutritional fortification, but calcium ions can also interact with hydrocolloids and proteins.

With gellan gum, ions can influence the formation and properties of the gel network.

This creates an important formulation balance.

Too little ionic interaction may provide insufficient structure.

Too much may produce an undesirable texture or change the behavior of the system during processing and storage.

Therefore, when developing a calcium-fortified plant-based milk, it is better to evaluate:

gellan level + calcium level + pH + heat treatment + homogenization

as a combined system rather than optimizing each variable independently.

🥤 Different Plant-Based Milks Need Different Solutions

Not every plant-based milk behaves in the same way.

Soy Milk

Soy protein can create significant stability challenges, particularly after heating and during long-term storage.

Gellan gum has been investigated for reducing precipitation and improving suspension stability in soymilk.

Pea Milk

Pea protein systems can have strong protein-protein and protein-interface interactions.

Recent research specifically examining pea protein and gellan gum found improved long-term emulsion stability compared with guar gum in the studied model system.

Almond Milk

Almond-based beverages often contain relatively low protein levels and can have problems associated with oil droplets and insoluble plant material.

Here, suspension and emulsion stability may both need attention.

Oat Milk

Oat-based beverages can involve starch, beta-glucan, oil and protein interactions.

The target texture is also different from a clear beverage, so the stabilizer system needs to be designed around a creamy but pourable mouthfeel.

The same gellan gum level should therefore not automatically be transferred from one plant-based milk to another.

⚙️ How Should a Formulator Approach Gellan Gum?

A practical development process might look like this:

Step 1 — Define the target texture

Decide whether the product should be thin, creamy, barista-style or closer to traditional milk.

Step 2 — Check the protein system

Identify the plant protein source and its concentration.

Soy, pea, oat and nut-based systems can behave very differently.

Step 3 — Select HA or LA

Start with the gellan type that fits the desired texture and suspension mechanism.

Step 4 — Test a low concentration

Do not start by trying to maximize gel strength.

Start with a small amount and increase gradually.

For example, a practical plant-based milk trial can begin around 0.03–0.05% gellan gum, then be adjusted according to the protein system, processing conditions and desired mouthfeel.

Step 5 — Optimize hydration

Gellan gum needs to be properly hydrated for consistent performance.

Incomplete hydration can make the formulation appear unstable even when the nominal dosage is correct.

Step 6 — Evaluate homogenization and heat treatment

The stabilizer should be tested under the actual processing conditions rather than only in a cold laboratory mixture.

Step 7 — Run storage tests

Check:

• Sedimentation
• Creaming
• Phase separation
• Viscosity
• Particle size
• Mouthfeel
• Pourability
• Stability after shaking
• Stability after heat processing

📊 A Simple Troubleshooting Guide

Problem	Possible cause	What to investigate
Sediment at bottom	Insufficient suspension structure	Gellan level, protein particle size
Cream layer	Oil droplet instability	Homogenization, emulsifier, gellan level
Too thick	Excessive hydrocolloid structure	Reduce dosage or change grade
Gummy mouthfeel	Network too strong	Lower gellan or review HA/LA choice
Instability after heating	Protein aggregation	Heat treatment, homogenization, pH
Calcium sediment	Mineral interaction/poor dispersion	Calcium source, addition order, homogenization
Different results batch to batch	Inconsistent hydration or processing	Mixing and heating conditions

🔄 Gellan Gum Is Only One Part of the System

It is important not to treat gellan gum as a replacement for good processing.

A stable plant-based milk normally depends on several factors working together:

**Protein selection

• particle size
• oil droplet size
• homogenization
• heat treatment
• pH
• minerals
• hydrocolloid system

= final stability**

Gellan gum can contribute to this system, but its performance depends strongly on the surrounding formulation.

This is also why a dosage that works perfectly in one soy milk may not work in a pea or oat beverage.

🚀 Where Is the Research Going?

The next generation of plant-based milk formulation is moving beyond simply increasing viscosity.

Researchers are increasingly looking at:

• Protein-polysaccharide interactions
• Interfacial adsorption
• Colloidal stability
• Heat-induced protein changes
• Rheology under realistic drinking conditions
• Long-term storage stability
• Barista performance
• Improved mouthfeel with lower hydrocolloid levels

Recent work on pea protein systems, for example, shows that the interfacial behavior of gellan-protein mixtures can be important for both stability and protein digestion.

This gives formulators a more useful way to think about gellan gum.

It is not simply a thickener.

It can be part of the microstructure that keeps a plant-based milk stable while maintaining the texture consumers expect from a milk-style beverage.

🌿 Final Takeaway

The main challenge in plant-based milk is not simply preventing separation.

It is achieving stability without sacrificing mouthfeel.

Gellan gum can help by creating a controlled weak network, interacting with plant-protein systems and limiting the movement of suspended particles and droplets.

But the best result comes from balancing:

Gellan type + dosage + protein + oil + minerals + pH + homogenization + heat treatment.

For plant-based milk, the goal is rarely the strongest possible gel.

The goal is a stable, smooth and drinkable system that still feels like milk.