How can alginate be better dispersed and hydrated?

Alginates (Take sodium alginate as an example) are natural polymers (biopolymers) or hydrocolloids obtained from brown seaweeds that are soluble in water when mixed under the right conditions. As a supplier of emulsifier equipment for over 20 years, through years of industry experience, we have learned that alginate is often used in the food, pharmaceutical and chemical industries as a thickener, stabilizer for products such as spreads, sauces and bakery products. agent and gelling agent. It can also provide great taste to foods in low-fat product formulations. Alginates have film-forming properties when mixed and dried at high concentrations, making them suitable for plant-based products such as vegetarian casings/casings. They are also used in pharmaceutical applications such as non-woven dressings often combined with CMC.

 

Traditional craft

Alginates come in powdered and granular forms, both of which have a strong tendency to agglomerate when they are added to water, and a number of dispersion and hydration methods are used to overcome this. Calcium interferes with the formation of gel structures, therefore, alginate should be dispersed in deionized water for full functionality.

A typical dispersion process is as follows:

*Fill the stainless steel mixing tank with water.

*Start the dispersion pan or agitator.

*Alginate is usually dry premixed with another powdered ingredient such as salt or sugar to separate particles and disperse more easily using a simple mixer.

*The alginate was carefully added at a controlled rate to the vortex created by the agitator in an attempt to reduce the formation of agglomerates. This must be done by the operator as quickly as possible, as powder incorporation becomes increasingly difficult as the viscosity of the mixture increases.

*Continue mixing until the alginate is fully dispersed and hydrated.

*A filtration step may be required to remove any agglomerates and/or unhydrated alginate.

 

Question

When dispersing alginate, a number of problems can arise during traditional dispersive mixing:

• Even with the above steps taken to reduce risk, clumps can easily form. Conventional mixers do not generate enough shear to break down these substances quickly.

• Controlled addition of powder to liquids can help reduce agglomeration formation, but this approach is impractical for large-scale production and can be exacerbated by operator error.

• Premixing alginate with other dry ingredients increases processing time.

• It is difficult to obtain the full potential yield using traditional methods.
• Combining alginate with other gums (pectins) can significantly increase viscosity, which can lead to localized mixing problems when mixing equipment cannot handle the increased viscosity and continues to move product around the container.
• Air incorporation can cause problems, especially at higher concentrations where the mixture is more viscous. Air entrapped in the mixture is difficult to remove and causes cloudiness of the clear gel.

Solution

Promake's high shear mixing technology effectively disperses alginate in a fraction of the time required by traditional mixers and agitators. The following is the working principle of high shear emulsifier:

Step 1,

The emulsifying tank is filled with deionized water and begins to pass through the recirculation pipe, the alginate powder is added to the feed hopper, and when the valve is opened, it will be sucked directly into the high velocity liquid stream by pumping force.

Step 2,

The powder/liquid mixture immediately enters the rotor-stator working head and is subjected to intense mechanical and hydraulic shearing. This ensures that it is completely dispersed and free of lumps.

Step 3,

The product is pumped back to the process vessel by the self-pumping action of the machine. Once the powder addition is complete, a short recycle completes the process.

Advantage

Using a high shear dispersing emulsifier instead of a simple stirrer or agitator in this application has the following advantages:

• The thickening effect of alginate is maximized and the utilization rate of raw materials is improved. Products can be reformulated with reduced amounts of alginate, thereby reducing raw material costs.

• The high shear emulsifier processing time is significantly reduced, eliminating the risk of unexpected temperature increases due to excessive mixing times.
• No need to premix alginate with other ingredients as it can be added directly to the emulsification tank or powder feed hopper.

• Caking-free blending.

• Operator error during powder addition is virtually eliminated.

• Powders can be added despite increased viscosity.

• Greater consistency between batches.