2023-07-20 16:45:24
The plastic materials traditionally used in food packaging and agricultural films are derived from petroleum, a non-renewable resource that will one day run out. Likewise, once their useful life is over, if they are not properly managed to revalue them in the form of energy or in the form of a new recycled plastic material, they represent a pollution for the environment, forming microplastics that can contaminate not only landfills, but also rivers, lakes and seas.
For this reason, the development of new polymeric materials made of biobased and biodegradable polymers, such as poly(lactic acid) (PLA), poly(hydroxyalkanoates) (PHAs), starch, cellulose and proteins, has gained great interest in short-term applications such as food packaging or films for agriculture. However, these polymers have worse performance than traditional plastics and, to improve their properties, different natural additives are used and composite and nanocomposite materials can be developed. To give particular and improved properties to these materials, they can be mixed with different natural additives such as pine resin derivatives (rosin or gum rosin and its derivatives), vegetable oils and essential oils (carvacrol, thymol, limonene), etc.
Likewise, to reinforce these materials, the use of organic loads obtained from the revaluation of by-products or waste from the food industry is of great interest. In this sense, food waste such as yerba mate, coffee grounds, fruit peels, kombucha, etc., are generally discarded once the infusion is consumed or the fruit eaten and are a raw material that can be used to extract particles, nanoparticles, bioactive components and others for use in the development of new, more sustainable plastic materials.
In this context, researchers from the Higher Technical School of Industrial Engineers of the Polytechnic University of Madrid (UPM) in Spain together with professors from the Polytechnic University of Valencia in Spain, the University of Quilmes in Argentina, the National Polytechnic School of Ecuador, the Santiago de Chile University and the Institute of Polymer Science and Technology in Spain, have developed biodegradable active packaging from agri-food waste.
Thanks to the work of this team, headed by Ángel Agüero Rodríguez from the UPM, it will be feasible to introduce food packaging and agricultural films into the circular economy, since they can be produced from biobased and biodegradable polymers and using particles obtained from agri-food waste, or resins obtained from trees as additives. Furthermore, once the materials have reached their useful life, they disintegrate under composting conditions in approximately one month.
Researchers have managed to create biodegradable active packaging from agri-food waste. (Photo: UPM)
The extraction of particles and nanoparticles with active properties from agri-food waste (yerba mate, coffee, algae, fruit peels, kombucha drink, etc.) allows these wastes to be revalued, giving them a second useful life. If these bioactive particles are also used to reinforce biobased and biodegradable polymeric materials, more sustainable composite materials with active properties (antioxidants, antimicrobial…) of interest for use in food applications such as food packaging and/or films for agriculture can be obtained.
Likewise, the use of natural additives such as those derived from pine resin, vegetable and essential oils, and others, makes it possible to improve the dispersion of nanoparticles in biopolymeric matrices and the compatibility between them. Thus, the extraction of natural additives from agro-industrial residues has shown that residues can be used to obtain bioactive components of interest to the plastic materials industry, since they not only improve the mechanical and thermal properties of biopolymers, but also provide them with specific properties (antioxidant, antimicrobial, hydrophobic, etc.) that allow the shelf life of food to be extended without the need to add preservatives, since antioxidant and antimicrobial agents They will be released from the plastic material (the container or the film) into the food or the crop in a controlled manner.
Agüero and his colleagues present the technical details of their research in the academic journal Polymers, under the title “Plasticized Mechanical Recycled PLA Films Reinforced with Microbial Cellulose Particles Obtained from Kombucha Fermented in Yerba Mate Waste.” (Source: UPM)
#Biobased #biodegradable #plastics #food #applications