Hydration of Xanthan Gum with Silverson High Shear Mixers

Xanthan Gum is widely used for its thickening and stabilising effect on emulsions and suspensions, particularly in the food industry.

Xanthan Gum, like many other hydrocolloids (gums and thickeners), can cause problems during processing and these problems can often be exacerbated by the processing equipment being used. For example, traditional agitators and stirrers do not produce the high shear necessary to quickly and efficiently hydrate Xanthan gum without forming agglomerates. This can lead to very long mixing times while the powder slowly hydrates. These long mixing times increase processing costs, can degrade the gel, and can lead to unwanted temperature rise – far from ideal for some applications in the food industry

When processing with a conventional agitator, even after a long mixing period, there is often still the need for a filtration stage, again increasing process time and costs.  Because this filtration stage removes any undispersed Xanthan gum the agitator has failed to hydrate, many formulations contain unnecessarily high levels of gum to compensate for the poor yield achieved when using conventional equipment. Conversely, if the agglomerates are not removed in a filtration stage, unhydrated gum that remains in the mix could gradually hydrate during storage, leading to undesired changes in viscosity and inconsistency between batches.

Conventional mixing equipment also struggles with dispersing powder into higher viscosity mixes and for this reason it is practically impossible to create high percentage gum solutions using these methods. Once viscosity increase has started, agitation of the solution and therefore powder dispersion becomes increasingly difficult. When using conventional equipment to try to avoid this the powder must be added to the vessel slowly in a controlled manner, further increasing the processing time and increasing the risk of problems caused by operator error.

Do these problems sound familiar? They can all be rectified with the use of a high shear mixer. To prove the effectiveness of high shear mixing equipment for this application, Silverson Machines have released an application video showing how a Silverson Batch mixer is able produce an agglomerate-free 2% Xanthan gum Solution in 10 minutes, a fraction of the time taken by conventional methods.

Here’s how it works: Xanthan gum is added directly into the vessel as quickly as possible, there is no need for carefully controlled powder addition. The gum does not need to be pre-mixed with other powders to aid wetting out or try to prevent agglomerates from forming because the high speed rotor/stator workhead creates a powerful suction which draws the gum and liquid straight into the workhead. This eliminates rafting on the surface of the vessel.

The powder and liquid are intensely mixed inside the workhead and then forced out through the holes in the stator.  Any agglomerates which may have formed are rapidly broken down. The mixture is projected back into the body of the mix.

In a short mixing cycle all of the material passes many times through the workhead, progressively reducing the particle size and exposing an increasing surface area to the surrounding liquid, accelerating the hydration process, maximising yield of the raw materials and eliminating the filtration stage. Using this method of mixing many products can be reformulated with reduced gum content, cutting raw material costs.

Silverson offers a range of High Shear mixers from laboratory to full scale production which are ideal for fully hydrating Xanthan gum, producing an agglomerate-free dispersion, batch after batch. The same mixer can be used for other gums and thickening agents in the food industry, whether you are mixing pectin, guar gum, CMC powder, alginates or starches, to name a few, a Silverson mixer will produce an agglomerate-free mix.

Silverson rotor/stator Batch mixers as seen in the application video, are able to eliminate agglomerates and improve quality, product consistency and process efficiency. These in-tank mixers can reduce mixing times by up to 90% when compared to conventional mixing equipment. Other in-tank mixers suitable for this application include the Silverson Ultramix. This mixer has a single-piece dynamic mixing head which creates a powerful vortex in the vessel, ideal for incorporating large volumes of powders. The Ultramix is also able to maintain excellent in-tank movement, even when processing higher viscosity mixes.

For larger batches, the Silverson Flashmix is capable of incorporating large volumes of powder and Silverson In-Line mixers can be easily retrofitted to existing plants.

Having helped hundreds of customers from all over the world find solutions to their Xanthan gum mixing problems, Silverson has produced a ‘How to’ video on the hydration of Xanthan gum which is available to view on the Silverson website, alongside the Xanthan gum application report, and on the Silverson YouTube channel.

If you’d like to discuss your Xanthan gum application with Silverson, please contact: sales@silverson.co.uk