Many people base the disposal of their food items on the small "best by" or "best before" labels printed in some portion on the food packets. Since 1973, the US Congress has been considering a bill requiring food manufacturers to list a date that perishable foods should be sold by. This bill, however, has failed to make it into law. 

Since then, the US came up with its own regulations on how to label perishable items. However, the scope of their laws is different in every state. The lack of uniformity confuses consumers even though the labels in question are on similar products packaged at the same time.

According to the Food and Agriculture Organization of the United Nations, a staggering 1.3 billion metric tons of yearly global food waste is accumulated due to production losses and consumer waste. This is a huge problem considering world hunger is still a problem faced in some parts of the world. 

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Food Waste Problem

Consumers see printed expiration dates on food items as accurate indicators that say that something is no longer safe for consumption. But in reality, the dates are merely set by manufacturers as criteria and part of their analytical strategy to assign a label they find suitable for a product. 

In 2015, the Food Marketing Institute, now renamed as Food Marketplace Inc., discovered that about 83 percent of shoppers in the United States had thrown out food based on the "best before" label. Truthfully speaking, The Telegraph reports that the label has nothing to do with whether a food is still edible but rather is meant to tell retailers to pull inventory from their shelves.

In the European Union, where laws on food labels are more uniform, the consulting firm, ICF, estimates that about 9.5 to 12 percent of all household food waste can still be blamed on date-marking issues.

Because of these inconsistencies regarding food expiration date labels and without better regulations, food and sensor scientists would like to put consumers in charge of telling whether the food they were to eat remains to be good or safe for consumption or not. Experts have long envisioned user-friendly devices that could give people a clear-cut message that: "This food is no longer safe for consumption."

Food Spoilage Sensors

To solve this problem, Firat Güder, an engineer at Imperial College London, has developed a budget-friendly cellulose-paper-based gas sensor for tracking food quality. In his paper published in ACS Publications, he described how some microbes that grow on top of meat and fish break down the fish's amino acids and release gasses like ammonia, as their colonies multiply.

Güder's sensor measures how well electrical current flows through the paper, and as the paper absorbs gases from inside a food container, the flow of current changes, signaling microbe growth. His sensors are responsive to the point that if you were to put them in a sealed container with ammonia inside, they would register a signal in mere minutes. 

Theoretically, consumers could install the sensors inside a product's wrapping after buying them. Because Güder's sensors use an electrical signal as a readout, users can simply tap on their phones to get readings from the sensor through an integrated radio-frequency tag, he says.

Meanwhile, Ken Suslick from the University of Illinois at Urbana-Champaign also creates sensors that can mark food spoilage. Rather than using a single measurement, Suslick's sensors torrent air across a series of different sensors to form a complex signal that can be refined and classified. This mechanism copies the way our noses sense and distinguishes gases. 

Suslick calls his sensor an electronic nose that uses a dispensable paper or plastic strip with different chemically responsive dyes printed onto it. The sensor is then primed into a handheld "sniffing machine" to test the quality of a food product.

Güder is still weighing on how his technology will make its way into the market. Using the company, BlakBear, to commercialize the technology, he is hopeful that many people can benefit from his science in the future.

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