The Expert's Corner

ROSS is known across the process industries for durable, reliable equipment and hands-on commitment to helping customers optimize their mixing process. When an organic nutraceuticals company encountered challenges in developing a new flavor emulsion on a competitor’s mixer, they reached out to the experts at our Test & Development Center for guidance.  The end goal was to elevate product consistency and production efficiency while maintaining quality and flavor. The assessment performed on the ROSS Laboratory High Shear Mixer Model HSM-100LCI-T documented the improvements sought, and helped their R&D team gain a better understanding of rotor/stator technology.

What is Emulsification?

For the customer’s product to be successful, a uniform and stable emulsion was key. Emulsification is a process that involves energy-intense agitation to combine two immiscible liquids and form a mixture that remains semi-stable when left for long periods of time. During this process, the minor liquid component (dispersed phase) is broken down into small droplets that get dispersed throughout the base liquid (continuous phase). Emulsifiers, having both hydrophilic and hydrophobic properties, are added to the mixture to reduce the level of surface tension between the two liquids. Some emulsifiers create a physical barrier around the droplets to increase stability, while others work through ionic action. Efficient mixing (creation of small droplets) and the effect of emulsifying additives (to keep individual droplets from coalescing) are two of the main important factors that dictate emulsion stability. Because various foods, pharmaceuticals, cosmetics, and chemicals exist as or contain emulsions, the process of emulsification is an integral manufacturing step that directly affects the shelf-stability, uniformity, efficacy and appearance of many products.

Lab Test Summary

The process started by adding purified water to a stainless steel beaker with humectants to retain moisture, preservatives to extend shelf life, antioxidants and flavor enhancers. The HSM-100LCI-T, equipped with a slotted head, ran at 3,000 rpm. The slotted stator design provides the most popular combination of high shear and efficient flow rates. It is well-suited for most medium viscosity mixing applications up to around 10,000 centipoise. A neutral oil was then added over a four-minute period at 10,000 rpm.

Once the above components were well mixed, flavoring and color were added to the batch. The batch became quickly uniform and samples were taken at 1, 2 and 3 minutes of mixing at 10,000 rpm.

 Particle Size Analysis:

Control Sample from Competitor’s Mixer

• Median particle size: about 9 microns
• Multiple distribution peaks around 2 microns, 8 microns and 80 microns.

Samples from ROSS HSM-100LCI-T

• Median particle size: ranged at about 6 microns
• Monomodal distribution.

Stability Test:

The emulsion prepared in the HSM-100LCI-T was allowed to sit for three days. No separation was observed.

Conclusion:

The ROSS HSM-100LCI-T produced a superior emulsion compared to the competitor’s mixer. It not only achieved a finer and narrower particle size distribution but also excellent stability over time. This translates to consistent flavor, uniform texture and striking appearance in the final product.

Advantages associated with the ROSS HSM-100LCI-T include efficiency, ease of operation, scalability and low energy consumption. The ability to quickly develop high quality emulsions in the lab is essential to establishing optimal cycle times and troubleshooting challenges in the production floor.