Top tips for avoiding food contamination

All parties involved in the food processing chain have a responsibility to ensure that food reaching consumers does not become contaminated. While manufacturers already take steps to prevent the main causes of contamination, thermal fluid could be a hidden contaminator. Here Clive Jones, managing director of heat transfer fluid specialist Global Heat Transfer, explains how thermal fluid choice and maintenance can prevent cross-contamination being a problem.

Cross contamination can occur at any stage of the food production chain, so food processing facilities have processes and procedures in place to remove any risk of product mishandling. These are built on an understanding of how cross-contamination occurs — food handling is one of the main causes of cross contamination.

For example, a worker may handle raw meat without gloves and then touch other food products without washing their hands. Food residue left on equipment can also provide opportunities for contamination, as well as the harmful bacteria often found on raw products, for example if fluid from raw meat drips onto uncovered products.

Food processing applications, such as brewing, baking or freezing, often require indirect heating or cooling generated from a heat exchanger and transported using thermal fluid. The fluid may absorb excess heat energy and take it away from the product, or transfer heat energy to the product.

Thermal fluid contamination

Heat transfer fluid is transported around a facility in pipes, meaning that it is unlikely to come into direct contact with a product. However, if any issues occur in the system that leads to leaks or breakages, the fluid could contaminate the product.

If food and beverage manufacturers use a standard heat transfer fluid and there is incidental contact with the product, the whole batch must be scrapped to avoid any contaminated food reaching consumers.

Food-grade fluid

In any environment where thermal fluid may come into contact with a consumable product, manufacturers should use food-grade thermal fluid. Food-grade thermal fluids must carry a HT-1 certificate, granted by the US Food and Drug Administration (FDA) or the NSF International, to be approved for use in food processing. They are typically colourless, non-toxic, non-irritating and non-fouling, so if they do come into contact with food and therefore consumers, they can help to lower the rate of potential recalls.

Food and beverage processing reactions take place at specific temperatures, so manufacturers require a fluid with precise temperature control. Global Heat Transfer’s Globaltherm FG, for example, can operate and maintain temperatures ranging from -20 to 326°C. It is claimed to have a good thermal oxidation stability and a lower viscosity compared to standard mineral oils, so can be easier to pump around the system. This thermal fluid has HT-1 certification and is accredited for use in kosher and halal applications.

Fluid maintenance

While incidental contact between the HT-1 certified fluid and the food product will not pose a risk to consumers, manufacturers should still do everything possible to prevent any maintenance issues that could lead to the fluid impacting production.

Thermal fluids degrade over time, especially when operating at high temperatures for long periods of time. Fluid degradation can cause a build-up of carbon and other by-products in pipes, reducing heat transfer efficiency and causing products to be cooked inconsistently. If the fluid is properly maintained, manufacturers can slow down the degradation process and reduce the risk of unplanned downtime.

To achieve this, manufacturers can implement a preventative maintenance program. This should include regular visual walk-round checks, as well as quarterly fluid sampling to determine the condition of the fluid. Engineers can take samples from a live, hot and circulating system to a laboratory for fluid analysis, using the results to plan preventative actions to maintain or expand fluid lifespan.

The food processing sector must uphold the highest standards to ensure food safety and prevent cross-contaminated products from reaching consumers. By selecting a food-grade thermal fluid and carrying out regular fluid analysis and maintenance checks, plant managers can help to ensure that their products are manufactured safely and efficiently.

Image credit: iStock.com/Smederevac