Sustainability is rising as an urgent focus for food producers, but achieving it can be a difficult task. Thankfully, there is a lifeline. Newer measurement technologies contribute to sustainability through optimized operations, waste reduction, and improved profitability, especially for products where texture is an important consumer criteria or brand differentiator.
The Challenge of Shear-Sensitive Fluids
Many food processing facilities producing ketchup, yogurt, mayonnaise, and other similar food products are equipped with state-of-the-art instrumentation for flow measurement. These devices are accurate and repeatable, delivering exactly what they are designed for in countless applications around the world. However, for shear-sensitive fluids, they can inadvertently contribute to the production process in an unexpected and costly way.
Contributing Factors
Production processes are specifically and carefully designed to keep shear-sensitive fluids whole and homogenous throughout all stages. However, some flow measurement instruments may unknowingly be causing damage to the structural integrity of shear-sensitive products. This may ultimately cause the texture or even the taste of the product to fall outside of quality control limits.
While this damage can sometimes be remediated by adding compensating ingredients or through additional reprocessing, if a production batch is too far out of specification, it must be rejected and disposed of. In either case, this translates into added production costs.
The Impact of Friction and Heat
Shear-sensitive fluids are especially sensitive to friction and heat. The process pipe walls may impact a shear-sensitive fluid's structure. Thus, these types of processes often feature low flow rates on relatively large pipe diameters to limit that impact. Those low fluid flow rates are tough to measure by some technologies, so corrective actions are often taken to optimize instrument performance.
For example, a small diameter magmeter selected to operate in its optimal measurement range because of the low process flow rates would need a reducer and expander installation to adapt it to the process piping it is mounted on. That pipe diameter transition can impact the fluid's texture. Other meter technology that features moving parts or flow restrictions can produce even more significant impact.
Food for Thought: Real-World Examples
Mayonnaise: A Highly Shear-Sensitive Aerated Product
Mayonnaise is an emulsion wherein at least 65% of the fluid's content by weight is oil. The oil is incorporated as small droplets into a base liquid composed of egg yolk, lemon juice, or vinegar. The egg yolk contains the natural emulsifier that is essential to stabilize the structure of this emulsion. Air bubbles can also be incorporated into this emulsion to achieve a desired fluffy mouthfeel.
Having an undersized flow meter at the packaging stage will subject the final fluid product to over-shearing. If the emulsifier cannot maintain the fluid structure under the resulting mechanical stress due to the collapse of air and oil bubbles, this can easily result in a 20 to 30% decrease in product texture.
Other aerated products such as ice cream, spreadable cheese, or chocolate mousse can be similarly impacted.
Yogurt: A Gel System Example
Yogurt gels are the result of the fermentation of milk by lactic acid bacteria. Adding proteins, additives like gelatin, gums, or starches, or draining whey for Greek types will produce a thicker yogurt. Undesired over-shearing in the manufacturing process resulting from under-sizing equipment, multiple pipe elbows, or long pipe runs reduces the product's texture, which must most often be compensated by adding expensive additives into the recipe.
To achieve a target texture, a reasonable shear rate for a Greek yogurt is less than 100 reciprocal seconds (1/s). For stirred yogurt, it is around 200 1/s. When an applied mag flow tube's diameter is half that of the process pipe to allow for the low flow rates, the shear rate range is greatly increased.
The KROHNE Solution: Straightforward Technology
Intuitively, the answer to this friction-caused challenge lies in keeping the shear-sensitive fluid within its optimal flowing state by not subjecting it to pipe diameter reductions, flow obstructions, or excessive bends. Doing so would reduce off-spec end products and would minimize reprocessing or the need for additional expensive ingredients.
OPTIMASS 7400: Advanced Measurement Technology
KROHNE's OPTIMASS 7400 full bore single straight tube Coriolis meter can measure reliably and repeatedly in shear-sensitive fluid applications at low flow rates while providing critical information for optimal process management. Its core measurements include:
- Mass flow
- Density
- Temperature
- Volumetric flow (if desired)
This advanced and unique technology can also announce and continue to operate in unexpected flowing conditions caused by entrained gases, air, or even solids. This feature can greatly help in batch process applications.
KROHNE's Expertise in Food & Beverage Industry
KROHNE's dedicated Food & Beverage division, staffed by industry specialists, demonstrates a deep understanding of the sector's unique challenges. The company offers a comprehensive range of measurement solutions for the food and beverage industry, including:
- Flow measurement
- Level measurement
- Pressure measurement
- Temperature measurement
- Inline analysis
Hygienic Certifications
KROHNE's instruments come with crucial hygienic certifications for food safety compliance:
- EC 1935/2004 conformity
- FDA approval
- EHEDG approval
- 3A approval
Application Versatility
KROHNE's solutions can be applied to various food and beverage manufacturing processes, such as:
- Beer production
- Dairy processing (milk, cream, cheese, butter)
- Fruit and vegetable juice manufacturing
- Soft drinks and mineral water production
- Chocolate making
Global Support and Customization
With a presence in around 100 countries, KROHNE offers local support, which is particularly appealing for multinational food processing companies. The company provides both standard instrumentation and customized solutions for more challenging applications, offering flexibility for clients with unique processing needs.
Conclusion
If you are experiencing unusual or inconsistent performance in your shear-sensitive food production processes, KROHNE may be able to help you identify some contributing factors and provide a solution you might not have previously considered. This approach not only aids in your quest for sustainability but also improves your bottom line by reducing waste and optimizing ingredient use.