If looking at the expiration date of food when shopping does not often convince some consumers, they will now have another, more reliable indicator, a sort of indicator.traffic light‘, in the literal sense, because this biosensor changes between the three colors (red, yellow and green) depending on the degree of conservation. Of course, the tones are interpreted the other way around: red gives free rein and green means danger.
The Polymer and Nanomaterials Analysis Group (Nanobiopol) at the University of Alicante (UA) has developed this technology that improves food packaging, also taking advantage of waste of the agri-food industry.
It is a colorimetric biosensor, meaning it changes color from the waste. blood orangetypical of the Valencian Community and with an annual waste production of one ton, also of beetas detailed from campus.
This new “intelligent and biodegradable» is a transparent film that has the ability to act as a sensor and offer the consumer additional information on the condition of the packaged food.
“When a product rich in proteins “It begins to decompose, its chemical structure changes, and volatile nitrogen compounds form in the atmosphere of the container, leading to a change in color of the designed material,” explain the UA researchers. Mª Carmen Garrigós And Alfonso Jiménez.
In this case, add the leaders of this advance, the initial red or pink colors indicate that the food cool is in perfect condition, but if the sensor turns yellow or greenish, the product is in the process of deterioration.
The Nanobiopol group of researchers from the University of Alicante, creators of the new material
All you need to do is incorporate a small piece of this sensor into the container containing the food for this reaction to work. Therefore, both distributors and establishments that work with fresh produce packaged or sold by weight, “they can offer the consumer a guarantee of food safety that complements expiration dates, also helping to reduce food waste”, highlighted the University of Alicante.
With blood orange and beetroot
The UA researchers selected blood orange – characterized by an intense red color – and beets for their potential chemical characteristics for this system. More precisely, they obtained active extracts rich in polyphenols, anthocyanins or betalains, thanks to rapid, sustainable and efficient extraction techniques based on microwave from the peel and pulp of the orange, as well as the stem and skin of the beet.
In the case of blood oranges, they are rich in anthocyanins, substances antioxidantssensitive to changes in pH which “make it possible to monitor the degradation of protein-rich foods such as chicken, fish or shellfish”. Likewise, betalains, present in beets, have also been used, substances which also have great antioxidant power and which respond to both changes of pH as well as temperature changes. “In the latter case, if the cold chain is broken during the transport of a food, the sensor would detect if a sudden change in temperature has occurred which could alter the quality and safety of the fresh product,” describe the researchers of the AU.
The discovery of this smart sensor is part of the project “New multilayer materials for intelligent food packaging systems with pH-sensitive biosensors (Multisens)”, coordinated by the Universities of Alicante and the University of Alicante. Polytechnic of Valenceand funded as part of the “R+D+i” 2020 call for projects from the National Research and Development Agency. Ministry of Science and Innovation.
The UA Polymer and Nanomaterials Analysis research group is dedicated to studying novel biomaterials from natural sources with biodegradable characteristics. Since its inception, the work team has focused its efforts on the development of new formulations of active systems for food packaging and has articulated a field of biopolymers to contribute to the reduction of the different types of waste generated, thus contributing to the circular economy.
