🍹 How to Prevent Pulp Separation in Acidic Fruit Beverages Using Gellan Gum

— A Complete Guide to High Acyl vs. Low Acyl Gellan Gum for Juice Stabilization



🧃 What Causes Pulp Separation in Acidic Juices?

In fruit juice production, pulp separation is one of the most frustrating problems. It leads to:

  • Poor product appearance
  • Inconsistent mouthfeel
  • Consumer dissatisfaction
  • Shorter shelf appeal

This issue is especially common in acidic fruit juices like:

  • Mango juice
  • Passion fruit nectar
  • Guava beverages
  • Lemon or orange juice
  • Berry blends
  • Tamarind drinks

These drinks are naturally low in pH and contain suspended fruit particles or pulp, which tend to settle at the bottom over time. This is where gellan gum comes in — a powerful natural stabilizer used to suspend pulp, prevent sedimentation, and improve texture.

🧪 Understanding Gellan Gum: Two Types, Two Functions

Gellan gum is a microbial polysaccharide used as a stabilizer and gelling agent. It’s widely used in the food and beverage industry, especially in juice and dairy applications.

There are two forms of gellan gum:

🔹 Low Acyl Gellan Gum (LA)

  • Creates brittle, firm gels
  • Requires calcium or other divalent ions to gel
  • Performs very well at low pH (as low as 3.0)
  • Best for clear juices, sparkling beverages, or pulp suspensions
  • Holds pulp particles in place even under challenging conditions

🔸 High Acyl Gellan Gum (HA)

  • Forms soft, elastic, flexible gels
  • Does not require ions to gel, but works best in controlled environments
  • Performs best at pH 3.8–4.2
  • Ideal for nectars, smoothies, or milky fruit drinks
  • Adds smooth mouthfeel and gentle suspension

⚖️ When to Choose LA or HA Gellan Gum

Choosing the right gellan gum type depends on the juice’s acidity, pulp content, texture goals, and processing method.

Formulation CriteriaBest Option
Juice has low pH (3.0–3.5)✅ Low Acyl Gellan Gum
Product requires strong pulp suspension✅ Low Acyl Gellan Gum
Clear juice or light-colored beverage✅ Low Acyl Gellan Gum
Thick juice or nectar-style drink✅ High Acyl Gellan Gum
Looking for soft, elastic, smooth texture✅ High Acyl Gellan Gum
Able to adjust pH to 3.8–4.2✅ High Acyl Gellan Gum

🧰 Common Causes of Separation When Using Gellan Gum

Even when using gellan gum, some juices still separate. Why?

🔍 Problem 1: Low Hydration Temperature

If the gellan gum isn't dissolved in water hot enough (must be ≥90°C), it won't fully hydrate, leading to weak gel formation.

🔍 Problem 2: pH Too Low for HA Gellan

High acyl gellan gum doesn't gel well below pH 3.8, so at pH 3.3–3.5 (common in mango or citrus juices), the gel is too weak to hold pulp.

🔍 Problem 3: Uncontrolled Calcium Ions

Even though HA gellan isn't ion-dependent, excess calcium from fruit can interfere, causing uneven or premature gelation and texture problems.

✅ How to Prevent Pulp Separation Using Gellan Gum

Whether you're using HA or LA gellan gum, here's how to get the best suspension results:

1. Hydrate Gellan Gum at ≥90°C

  • Always dissolve gellan gum in hot water (90–95°C)
  • Stir for at least 20 minutes until fully dispersed

2. Adjust Juice pH

  • LA gellan works well at low pH (3.0–3.5)
  • HA gellan needs pH 3.8–4.2 for stable gelation
  • Use food-grade buffers (e.g., sodium citrate) to raise pH if needed

3. Use Sequestrants (if necessary)

  • Control natural ions like calcium and magnesium
  • Add sodium citrate or SHMP to avoid uneven gelling

4. Homogenize Before Gel Sets

  • Homogenize the beverage while still hot (above 60°C) before gellan starts to set
  • This preserves the gel structure and disperses pulp evenly

5. Fine-Tune Dosage

  • Typical usage levels:
0.025–0.035% for LA gellan gum
0.035–0.05% for HA gellan gum
  • Start low and adjust based on texture and suspension needs

🧪 Real-Life Applications

✅ Mango Nectar with HA Gellan Gum

  • Adjusted pH to 4.0
  • 0.045% HA gellan gum fully hydrated at 90°C
  • Smooth, shelf-stable, no separation after 30 days

✅ Passion Fruit Juice with LA Gellan Gum

  • pH 3.3, no adjustment needed
  • 0.03% LA gellan gum + controlled calcium
  • Strong pulp suspension with crystal-clear appearance

🎯 Final Takeaway: Match Gellan Type to Your Juice

To prevent pulp separation in acidic fruit beverages:

  • Use Low Acyl Gellan Gum for low pH, clear juices, and strong suspension
  • Use High Acyl Gellan Gum for creamy, thicker juices if pH can be adjusted
  • Focus on hydration, pH control, ion balance, and timing of homogenization

By selecting the right gellan gum and following correct processing, you can create stable, attractive, and premium-quality juices.