Dispersing gums & thickeners, such as Carrageenan, with Silverson High Shear Mixers

Many food applications rely on the properties of gums and thickening agents such as pectin, xanthan, locust bean, carrageenan and acacia to give the end product the characteristics the manufacturer desires. Gums such as these can improve the “mouth feel” and texture of the end product as well as enhancing stability and shelf life. But they can cause a number of problems during the manufacturing process and can be difficult to disperse and hydrate correctly and efficiently.

For example, most gums and thickeners are prone to forming agglomerates, undesirable lumps or "fish eyes" when added to liquid. These agglomerations consist of partially hydrated material with a dry powder core, resulting in poor quality and inconsistency between batches. This makes it difficult to obtain full yield of the raw materials, especially when using conventional stirrers and agitators. Traditional agitators struggle to effectively disperse these agglomerates, as they merely wash the surface, requiring extensive mixing times to complete hydration. As a result, many formulations contain unnecessarily high levels of gums to compensate for the poor yield, which increases raw material costs. Premixing the gum with other powdered ingredients before adding to the water is often carried out to reduce the formation of agglomerates, but this is only partially successful and adds to the process time.

Furthermore, certain ingredients require shear to activate and obtain functionality, which cannot be accomplished with agitators alone.

Unlike conventional mixers or agitators, Silverson high shear mixers utilise specialised rotor/stator technology that subjects the powdered and liquid ingredients to intense mechanical and hydraulic shear as they are drawn into the workhead then forced out through the holes in the stator at high velocity. This mixing technology is especially useful for applications using gums and thickening agents, as the high shear action will swiftly disperse powders and disintegrate agglomerates, resulting in a uniform, consistent product, time after time.

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 to accelerate 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 is completed as rapidly as possible, cutting mixing times by up to 90%.

Processing times can be further reduced with a Silverson high shear mixer as premixing of gum with other powders or non-aqueous phase ingredients is not required – this also simplifies the process.

Other advantages of using high shear mixing technology include obtaining the maximum yield from raw ingredients. As all the agglomerates in the mix are broken down by the high shear action of the mixer there is no wastage, allowing the manufacturer to reduce the gum content and their raw material costs.

Silverson has recently added a new 'How to' video on dispersing Carrageenan to their extensive video library. Previous videos in the how to series include guides on Xanthan Gum, Pectin, Gelatine, Starch, CMC and Locust Bean Gum, amongst others.

In this latest video, viewers can see how Silverson High Shear mixers are able to overcome the common problems associated with mixing different types of Carrageenan and create an agglomerate-free dispersion. In particular, the video shows how a Silverson in-tank Batch mixer is able to disperse Carrageenan as quickly as it is added to the vessel. The high speed, high shear mixing action will rapidly draw the powder and liquid into the workhead, where any agglomerates are broken down as they pass through the precision gap between the rotor and stator.

There are other mixers in the range also suitable for this application and hydrating and dispersing other gums and thickening agents. From laboratory to production-scale, Silverson Machines offers an unparalleled range of high shear mixers.

Silverson Laboratory mixers are ideal for R&D and small batches, and because the mixers are all built to the same tolerances, they offer users an accurate means of predicting the performance of larger powder/liquid mixers in the range, making the scale-up process a simple task.

For larger scale production, the Silverson Flashmix offers a highly efficient solution for gums and thickeners. The machine literally forces the powder into the liquid stream, concentrating its efforts on the small amount of product in the mixing chamber where the two streams mix on contact, so there's no time for agglomerates to form. Our In-Line mixers are also suitable for this application and can be easily retrofitted to an existing plant.

To find out more, please visit the Silverson website.

For more information on Dispersing gums & thickeners, such as Carrageenan, with Silverson High Shear Mixers talk to Silverson Machines Ltd