Food Safety Roundup: Three Sensing Technologies for Detecting Hazards in Our FoodJuly 23, 2018 by Robin Mitchell
Food safe sensors could tell us if food has gone bad. This could be beneficial for both health and the environment.
Electronics are changing the way we eat every day. From robotic field maintenance to supply chain maintenance in shipping, we rely on technology to grow and transport our produce. But what about informing us on food safety? Here are three ways engineers have devised sensors that can help us determine if our food is safe to consume.
Food waste has long been a problem, especially as we increasingly must consider our use of finite resources. A great deal of food waste is the result of consumers throwing food away when it goes “bad”. But what defines “bad”?
It is well known that food should be eaten before its use-by-date, but some argue that this is an arbitrary date that is decided by the manufacturer in such a way that increases their profits. Others disagree and say that this date is specifically chosen to reduce the chances of consumers falling ill from potentially dangerous spoiled produce such as meat.
The future of the food industry is full of sensors. Disposable sensors may help track produce, including monitoring its environmental factors.
Here are three different approaches to sensing whether our food is still safe to consume.
A Tiny Sensor for Detecting E. coli
E. coli bacteria is both dangerous and responsible for many food poisoning cases—all while being difficult to detect. Food that may smell alright can easily contain this nasty pathogen. It is a widespread bacteria. For example, it is estimated that up to two-thirds of fresh chickens in UK supermarkets are contaminated.
Carlos Filipe, a chemical engineer at McMaster University, and his team have created a small postage stamp-sized sensor that glows when it detects the presence of E. coli. This sensor (if applied to product packaging) could be a good indicator of “bad food” but it is limited to E. coli, which is easy to kill off via proper cooking practices. Such sensors are also passive and do not contain monitoring devices that could relay real-time data to aid manufacturers how long their products are really lasting.
Sensing the One Bad Apple
Some produce is especially sensitive to nearby food. It can go bad faster when near other food that has gone bad. For example, apples begin to release ethylene as they ripen, and ethylene causes apples to ripen faster. This forms a positive feedback loop and is the source of the idiom "one bad apple can ruin the whole bunch".
C2Sense is a company that is aiming to produce food-safe sensors for the IIoT (industrial internet of things) with the goal of preventing batches of food from going bad. The C2Sense sensor can detect ethylene in incredibly small traces, which can alert food producers that there is a bad apple in a batch that may implicate that batch. It's also capable of sensing ammonia, which is useful in monitoring the environment around chickens.
C2Sense sensor. Image courtesy of C2Sense
While similar sensors have been available for a number of years, C2Sense have made theirs both cheap and highly sensitive which are two useful qualities when dealing with IoT environments (many simple devices all taking readings).
The ethylene sensor was developed through research at MIT in 2012, conducted by John D. MacArthur Professor of Chemistry Timothy Swager and his team. Swager continued his work on food sensor technologies and actually produced another entry on this list using carbon nanotubes.
Carbon Nanotubes Find Its Way into Another Application
Back in 2015, MIT chemists, again led by Timothy Swager, developed a method for using carbon nanotubes to determine when food has gone bad. Carbon nanotubes can be chemically altered to detect specific gases and meaty products release a special type of gas when they go bad called biogenic amines.
If carbon nanotubes are modified with metalloporphyrins (central metal atom surrounded by nitrogen-containing rings), where the central atom is cobalt then the carbon nanotubes then the resistance of the carbon nanotubes increases as the presence of biogenic gasses such as putrescine and cadaverine increases (i.e., resistance is proportional to the badness of the food).
The carbon nanotube device from MIT. Image by Sophie Liu via MIT News.
This sensor, too, could take part in C2Sense's IIoT platform. Given their low power demands and capability of hooking up to a smartphone application for remote monitoring, these sensors check many of the boxes for an easy-to-implement IIoT system for food safety.
To get food sensors into packaging is going to take a large technological effort. Food is packaged in units that are sold in the billions every single day and producing electronics on that scale to measure the level of toxins in food would cost a correspondingly large amount.
The investment, however, may be worth it. By monitoring our food better, we could reduce waste and inefficiencies, possibly lowering costs overall. More importantly, it could improve public health by reducing the number and severity of outbreaks of foodborne illnesses.
What other food-related advancements have you seen or taken part in designing?