Moisture Detection Adds To Cold Chain Capabilities

Wednesday, April 13th, 2022

Image Courtesy Of Mettler-Toledo

A simple drop in temperature in frozen products can cause problems such as contaminants and unwanted moisture entering the food, resulting in potential illnesses or forced discarding of products.

The introduction of metal detectors could potentially solve these problems before they arise. Few people think of metal detection systems when considering cold chain production lines.

Nigel Wong, Head of PI Market Support Centre and Product Inspection at Mettler Toledo, reveals that this technology can, in fact, play an even more important food safety role than people think.

Cold chain logistics and technology has had a major impact on the quality and safety of food throughout Asia, and indeed across the world.

A recent study by Future Market Insights suggests that the market for cold chain packaging solutions will grow at more than 14.5 percent CAGR between 2020 and 2030, partly due to changes brought about by the COVID-19 pandemic, with more emphasis on e-commerce and demand for efficient storage.

It might be thought that the only way to monitor the effectiveness of a temperature- controlled supply chain is by directly controlling and measuring the temperature of the products at each stage. However, there is another way – one which utilises equipment that is often already being used in food production environments to perform a critical role.

Metal detection systems can contribute to the cold chain by monitoring product moisture content, rather than product temperature, in addition of course to their primary task of detecting metal contaminants such as ferrous, non-ferrous and stainless steel.

Reading The Signals

Every product gives a specific product signal, based on its composition and its packaging, and this signal shows up in a metal detector’s histogram data in a consistent way. Metal detection technology operates by monitoring product signal changes – when a product gives back a different signal, then it is clear that something is amiss.

Usually, this is a metal contaminant, but in a cold chain environment, where the product is supposed to be kept at a specific temperature and a specific condition, a product signal change can indicate that the temperature has fallen out of tolerance.

As a frozen product thaws, it will have more moisture, and this presents a different product signal in the histogram data, alerting an operator to a potential problem.

There may be many reasons why the temperature control is failing, but the alert from the metal detector allows an early investigation to take place, and any issues with upstream temperature control to be rectified. The metal detector could therefore help save a huge amount of cost in wasted product and wasted production time.

Advanced Sensitivity

Although clearly not as accurate a monitoring tool as temperature measurement, this capability of metal detection systems to monitor moisture can be a great advantage to food manufacturers in the cold chain sector. The sensitivity of the detection device is made even more acute when using advanced metal detectors such as Mettler-Toledo Product

Inspection’s Profile Advantage and M34R GC, which includes multi-simultaneous frequency (MSF) and dual-simultaneous frequency (DSF) technology respectively. This allows the machine to operate at more than one frequency, with the possibility to suppress the product signal, so that variations become even more apparent, resulting in both contaminants and moisture changes becoming more obvious.

Not every metal detection system has MSF or DSF built in, but a system such as the company’s ASN 9000, for example, though without MSF or DSF, does provide the histogram data display, so could be used to monitor moisture in a cold chain environment.

With the right equipment and the right operator training, cold chain food manufacturers can add another layer of protection to their temperature-controlled operation and enjoy the spin-off benefits of enhanced product quality and safety, brand protection and cost efficiency too.