Food processing is an overlooked yet sophisticated aspect of modern life that keeps the world fed and, where possible, healthy. Some food processes mainly depend on heating and, thus, need powerful heating units to sustain required temperatures. This post will examine these processes and how immersion heaters can facilitate them.
Pasteurization refers to eliminating disease-causing pathogens that may reside in various foods and beverages. Examples include E.coli in milk or salmonella and listeria in fruit drinks. Some meat products may get pasteurized as well. Pasteurization is a heating process where handlers use controlled heat to kill these germs.
A similar process to pasteurization is blanching. It deactivates enzymes in vegetables that would lead to a loss of their colour, flavour or texture.
Temperatures requirements can vary depending on the target food or beverage. The typical temperature range for most food pasteurization sits between 62 to 90°C (143.6° F – 194° F). For example, the pasteurization of milk requires a temperature of at least 72° C (161° F) for a minimum of 15 seconds. Immersion heaters can sustain these temperatures as needed, and food processing plants often use them for this procedure.
Sterilization refers to the removal of any micro-organism in a particular food product. It, too, is often a heating process. Food processing plants may use dry heat, moist heat, or irradiation to remove unwanted microbes. With that said, some facilities may opt for non-heat-related forms of sterilization using chemical usage or filtration.
On the surface, sterilization may sound identical to pasteurization, but there are differences. Sterilization is often used on food products that have a longer shelf life and lower acidity (low pH balance).
Foods that undergo sterilization typically require a temperature of 100°C or higher for extended periods (than pasteurization). Examples of such foods include jarred baby food and canned fruits and veggies. Handlers place the contents of canned foods in an autoclave and heat them for 20 minutes at a temperature of 121˚C. An immersion heater can supply vessels with heat transfers that can sustain such temperatures for their required length.
A less recognized food process is ultra-high temperature sterilization (or UHT for short). As its name implies, this procedure is reserved for food and beverage products that require significantly high temperatures. The most common target are liquids with low viscosities.
Food technicians apply UHT after a product has undergone sterilization, which usually lasts only a few seconds. This process eradicates all micro-organisms that might leave some behind, unlike pasteurization and sterilization. By extension, this allows food products to have a longer shelf life.
Typical food products that undergo UHT treatment include dairy products, wine, soups and honey. For these foods to successfully go through UHT, food processing plants need more robust heat sources. For example, it’s not uncommon for temperatures to reach 135 – 150˚C (275° F – 302° F). Immersion heaters can help sustain such temperatures. Ones with tubular heating elements, in particular, demonstrate high efficacy for these requirements.
If you’re making a new foray into food processing or expanding an existing operation, consider how an immersion heater can help. Different kinds of immersion heaters can facilitate food processing, some of which may be better suited for your operation. Here at Wattco, our scientists and engineers build a range of immersion heaters that can suit your needs. Our representatives can direct you to the right choice based on your application.
Get in touch with a Wattco representative to help you determine the best immersion heater for your food application.