Stale food can now be identified using a sensor 

What do you do when food gets spoiled? You throw it away, of course. Wait, but how do you understand whether or not they have gone stale? Well, it either smells really bad or you accidentally consume it and then have to spit it out. That’s quite a tedious and often harmful process. 

Now imagine if there was a certain sensor technology that could easily identify rotten food. That would be great, right? Well, it turns out that such a technology does exist and has only recently been innovated by researchers based at South Korean Pusan National University’s Department of Biomaterials Science. Deemed as the portable molecular sensor, it can quickly identify spoilt food. How?  

Food items like fish, meat and cheese often release a series of low molecular weight organic nitrogen compounds called biogenic amines (BAs) whenever they decompose. Now, if ingested in small amounts, these Bas can cause hormonal changes, while large amounts can lead to serious health issues. But if they are detected during food storage and distribution, that saves a lot of unnecessary hassles. Well, that is exactly why the brand-new, cutting-edge portable molecular sensor has been pioneered. This device can easily and rapidly trace the presence of BAs by simply changing colours. How cool is that!  

This could easily alert us against eating spoiled food, help us to maintain food quality and even demonstrate effective food storage and distribution conditions in the long run. This novel research has been published in an article released in the journal Food Chemistry.  

Okay, but how was the sensor developed? As it turns out, the team first blended the distinct colour-shifting quality of polydiacetylene (PDA)-based hydrogen molecules with that of the BAs and then mixed the combination further with something called alginate solution. This resulted in a 3D porous structure with large surface area on the food that was revealed in the form of changing colours in the sensor.  

For instance, the sensor can easily trace biogenic amines such as cadaverine and propylamine (both in liquid and vapour state) that determine the condition of meat such as pork. Now, if the condition is still fresh and edible, the sign should be blue, however if it shows red, then it has turned stale. If the colour is in between, then too it is safe to discard that food as it is on its way to spoilage.  

What’s interesting is that that sensor is made in such a way that it is highly portable, light-weight and doesn’t need any complex analytical setup or trained official to operate it. Can you guess what this means? Yes, it can be used by layman like you and me or the workers at food storage facilities and logistic chains, that too hassle-free.