Maximise yield, eliminate agglomerates and reduce mixing times when dispersing gums and thickeners with Silverson High Shear Mixers – giving you the best results.
Many products rely on the properties of gums such as pectin, xanthan, locust bean, guar gum, gelatine, alginates or CMC, to give end products the characteristics the manufacturer desires. Used for their rheology modifying properties, these gums, along with others, can be used by manufacturers to alter viscosity, flow behaviour and texture of products. For example, gums are commonly used to improve “mouthfeel” in food products.
Generally, gums and other hydrocolloids such as starches make up a very small proportion of a formulation – sometimes as little as 0.1% is enough to achieve the required change in viscosity or to stabilise the end product. This video demonstrates the viscosity and flow properties of properly hydrated Xanthan Gum from 0.25% up to 6%
But even when processing small percentages, most hydrocolloids cause a number of problems during the manufacturing process and can be difficult to disperse and hydrate correctly and efficiently.
Most gums are prone to forming agglomerates when added to liquid and full yield of thickening effect is difficult to obtain using traditional methods such as conventional agitators. The mixing system plays a crucial role in the final viscosity obtained as inadequate dispersion and hydration can exacerbate the formation of agglomerates in the mix which will ultimately reduce the thickening effect achieved. As a result, many formulations contain unnecessarily high levels of gums to compensate for the poor yield, which increases raw material costs. In a Case Study library on the Silverson website, you can read about how one manufacturer was able to reduce the amount of pectin in their formulation by 20% by switching from an agitator to a Silverson High Shear Mixer. In this case, the agitator was so inefficient at dispersing the pectin that the operators were adding up to 20% more than was needed to account for what was being lost through the filtration stage that was required to remove the agglomerates. The agitator could not break down these agglomerates once they had formed and did not produce sufficient movement in the tank to stop partially hydrated pectin from sticking to the agitator shaft, blades and walls of the mixing vessel. By switching from a conventional agitator to a Silverson High Shear Powder/Liquid mixer for this application, the manufacturer not only saved money, but was able to eliminate the filtration stage from their mixing process, reducing their overall mixing times.
When mixing hydrocolloids, mixing times can often be lengthened by the practice of premixing gums with other powdered ingredients before addition to the water. In some cases, gums such as Locust bean gum are mixed with other hydrocolloids like Xanthan Gum, as the resulting gel has properties that are not achievable with either ingredient alone. But in other processes, the premixing of gums with powders is carried out to try to reduce the formation of agglomerates, but this is only partially successful.
Mixing times can be lengthened further depending on the type of mixing equipment being used. As mentioned earlier, conventional agitators do not produce sufficient shear to rapidly break down the agglomerates and long mixing times can cause degrading of the gum and a poor quality dispersion. High Shear mixers should be used in order to obtain the best results. To successfully disperse and rapidly hydrate difficult powders, high shear mixing technology can produce an agglomerate-free dispersion and hydrate gums in a fraction of the time taken by conventional agitators.
The high shear action of a Silverson mixer ensures that in a short mixing cycle all of the material passes many times through the machine’s workhead, progressively reducing the particle size and exposing an increasing surface area to the surrounding liquid, accelerating the hydration of the gum. As the product is forced back into the body of the mix, any agglomerates are broken down as they pass through the rotor/stator workhead. This process can cut mixing times by up to 90% and achieve maximum yield from the raw materials. By improving the dispersion of the gum, Silverson’s high shear mixing technology also improves the quality and consistency of the end product.
Processing times can be further reduced with a Silverson High shear mixer as premixing of gum with other powders or non-aqueous phase ingredients (for the reduction of agglomerates) is not required – this also simplifies the process.
The capabilities of Silverson High Shear mixers for the effective dispersion of gums and thickeners are demonstrated in the Silverson ‘How to’ video series featuring videos on Xanthan Gum, Guar Gum, Pectin, Gelatine, CMC, Alginates and most recently Locust Bean Gum.
Watch ‘How to Mix Locust Bean Gum’ on the Silverson YouTube channel.
For more information, read our Locust Bean Gum application report on the Silverson website.
www.silverson.co.uk
