Tomatoes, are they fruit or vegetable? The long debate has constantly shocked people when they find out it is, in effect, not a veggie. But, could the red juicy fruits also be made into bioplastics? This is what José Alejandro Heredia has been investigating for the past years in Spain.
The goal of Heredia’s team of scientists was to create an alternative to plastics derived from petroleum, which have excellent properties for food packaging, but, when they end up in the sea, take 450 years to degrade, accumulate and cause problems for flora and fauna. ocean fauna.
Produced from tomato remains and skin, and decomposing in just one month in seawater, Heredia has successfully created an innovative bioplastic with properties similar to those that protect commercial packaging.
The Institute of Subtropical and Mediterranean Horticulture (IHSM) “La Mayora” in Malaga, Spain, was created to unite the efforts of the groups of the pre-existing Experimental Station
“La Mayora” of the Higher Council for Scientific Research (EELM-CSIC) and groups from various departments of the Faculty of Sciences of the University of Malaga (UMA) to promote and coordinate more efficiently the scientific research in intensive horticulture and subtropical fruit growing that had been developing in the two entities.
One of the Institute’s researchers, José Alejandro Heredia, is currently working on his project titled “Circular bioeconomy for food packaging: use of waste from the tomato canning industry”. His research aims to provide, in terms of circular bioeconomy, sustainable and economically viable solutions to the massive use of petroleum-derived plastics in food packaging by manufacturing multifunctional bioplastics from under-utilized and non-commercial agricultural waste. Therefore, the project plans to lead to a global reduction in plastics used in food activities. In particular, the residues resulting from the industrial processing of the tomato fruit will be used as bio-renewable raw material, in combination with other materials such as paper, to manufacture products of biological origin and are likewise biodegradable using ecological technologies and that are also easily scalable for large production volumes.
These products will offer the same benefits as those made with petroleum-derived plastics, but will be biodegraded into non-toxic substances, thus avoiding the problem of collection and disposal after use. The physical properties of these products will be designed to be equivalent to those of common plastics through environmentally friendly chemical modifications. Finally, the environmental and economic sustainability of bioplastics production will be evaluated by determining the environmental impact through life cycle analysis and production costs, respectively.
Cellulose is extracted in a purified form from the leaves, stems and skin of tomatoes that are discarded in the canning industry after making tomato sauce or ketchup. Heredia works with the cellulose obtained from these remains to create a material capable of being modified with antibacterial bioactive substances and antioxidants that have properties for food packaging and that can additionally degrade in a minimum time compared to plastic containers.
This process creates a robust and transparent film with multiple applications. The resulting bioplastic can repel water, protecting content inside. Colorwise, it can have pearly shades, be fluorescent, or simply be different colors depending on the light exposure. However, we can think of the material as much more than an alternative to plastic bags; it can also be used to create accessories.
The innovative bioplastics can also be used to make ‘Smart packaging’. After they are used to protect food and the plastic begins losing its initial colour, it means that the plastic has absorbed water, is starting to lose its structure, and is beginning to lose antioxidant properties. It works as a “sensor” to indicate signs that a material that surrounds a food is beginning to deteriorate, which in the medium term can affect the food that it surrounds, according to the researcher.
Using a sustainable protocol called “green chemistry”, the material can also be used to coat the interior of a can. The researcher ensures that once this process has been carried out, it is “as good” as the current commercial oil derivatives, since they make the metal “resist corrosion very well and do not migrate towards the food”.
However, the researcher regrets, its commercial application is far from reaching, since the plastics industry needs to be able to use the same machinery for this change to be economically viable, which would mean a revolution for the environment and food sustainability.
Heredia, unfortunately, believes this new plastic will not be used by the sector for a long time, because the plastics industry needs to be able to use the same machinery for this change to be economically viable. A revolution for the environment and food sustainability is necessary first.