labelsintelligIT COULD SOLVE THE PROBLEM OF KNOWING THE STATUS OF PACKAGED FOOD OVER TIME WITHOUT NEEDING TO OPEN THEM.

A color-coded smart label could alert consumers if a carton of milk has turned sour or a package of gofio has spoiled without needing to open the containers..

This smart tag, that will appear on the packaging, It could also be used to determine if medications and other perishable products are still active or fresh.

The creators of this new application presented these food labels that change color as they deteriorate, within the framework of the 247 National Meeting and Exposition of the American Chemical Society (ACS), which was held in Dallas, United States.

“This label, which has a gel consistency and is really cheap and safe, can be widely programmed to mimic almost all environmental deterioration processes in food”, highlights the main researcher of the study, Chao Zhang, from Peking University , in china.

In his view, Using these labels could potentially solve the problem of knowing how packaged fresh perishable foods fare over time.. “A real advantage is that even when manufacturers, Grocery store owners and consumers don't know if food has been improperly exposed to higher temperatures, which could cause its deterioration, The label provides a reliable indication of product quality”, Zhan assures.

The labels, which are approximately the size of a grain of corn, They have various color codes, so orange or reddish red would mean that the food is fresh, a color that changes to orange over time, yellow and green, indicating that the food is spoiling.

“Colors mean a range of between one hundred percent fresh and one hundred percent spoiled. For example, If the label says the product should remain fresh for 14 days in refrigerated conditions but this indicator is orange, means the product is only about half as fresh, so the consumer knows that the product is edible for only another seven days if kept refrigerated”, this expert explains.

[quote]The tags contain tiny metal nanorods that, in the different stages and phases, They can have a variety of colors: Red, orange, yellow, verde, blue and violet[/quote]

The researchers developed and tested the tags using ‘E. Coli ‘, a bacteria that spoils food causing gastrointestinal problems, in milk as a reference model. “We synchronized successfully, at various temperatures, the process of chemical evolution on smart label with microbial growth processes in milk”, subraya Zhang.

The labels, which can also be customized for a variety of other foods and drinks, contain tiny metal nanorods that, in the different stages and phases, They can have a variety of colors: Red, orange, yellow, verde, blue and violet, according to Zhang.

“The gold nanorods we use are inherently red, dictating the initial color of the labels (this expert specifies). Silver chloride and vitamin C are also in these indicators, reacting slowly and in a controlled manner. With the time, metallic silver gradually deposits on each gold nanorod, forming a silver layer, that changes the composition and forms the chemical particle, so the color of the label would be different.

Therefore, since the silver layer thickens over time, the color of the label develops from the initial red to orange, yellow and green, even, blue and violet.

Although nanorods are made of gold and silver, a label like that would be very cheap, with a cost for all the chemicals of this small indicator less than a cent on the dollar (0,002 $).

In addition, The reagents on the labels are not toxic and some of them (like vitamin C, acetic acid, lactic acid and agar) They are even edible”, destaca Zhang, whose research has been published in the journal ACS Nano.