Page 40 - Food&Drink Magazine Aug-Sep 2021

FOOD SAFETY
Why metal detection is hard
How good is good enough when it comes to food safety? And what level of risk are we willing to accept? Foodmach director Phil Biggs looks at how to avoid the horror of metal contaminants in food and beverage manufacturing.
THE cost of food safety failure can be enormous, resulting in serious damage to both consumer health and your brand. Metal detectors are a given in food processing facilities. They are most commonly used at the end of the line and as the last line of defence to support food quality and safety before a packaged product is on its way to the consumer. But the core technology has always had its limitations. Signal interference from external noise, the product ingredients and packaging, and the size, shape, orientation and sensitivity of the metal in the contaminant can all contribute to false detections or worse, no detection.
media. Global Food Safety Standards dictate that fragments above 7mm be detected and removed. However, research shows that customers prefer anything above 2mm removed (or ideally, nothing at all).
Although production lines are designed to minimise the number of metal-on-metal parts, given how industrialised
THERMO SCIENTIFIC’S
instance, assuming that one out of every one million packs contains a metal fragment; at a pack/second, 16 hours a day, 5 days a week, that’s a potential escape about every 3-4 weeks.
Depending on the efficiency of your metal detector, it’s like playing roulette.
THE CHALLENGES
So why is it so hard to detect metals in food? A simple analogy may help: why does a coin or piece of jewellery set off a metal detector on your outbound flight but not your inbound flight? Why the inconsistencies? The same unpredictable performance can exist when trying to detect metal in food. Metal detection is easy – when it works – but it doesn’t always work.
The core principle of operation for food metal detectors is that a transmitter excites a radio frequency signal. As food contaminated with metal transverses the aperture, it interferes with the signal and triggers a detection.
40 | Food&Drink business | August/September 2021 | www.foodanddrinkbusiness.com.au
While metal detection technology has evolved slowly over the years, food processors' challenges have changed rapidly. There are increasing regulatory demands, retailer detection mandates and greater productivity demands. The stakes are higher, too: the potential for a costly recall and collateral damage via social
70%
SENTINEL MULTISCAN DETECTORS ENABLE USERS TO IDENTIFY CONTAMINANTS THAT ARE UP TO
SMALLER IN VOLUME THAN PREVIOUS TECHNOLOGIES.
our food system is, the potential for ‘extraneous metal materials’ exists and can cause product recalls. Every detection system has a probability of an escape. For