Between 118 and 138 million tonnes of organic waste is generated worldwide each year, with waste from the food production and distribution chain accounting for 100 million tonnes of the total. Only around 25% of all this bio-waste is collected and recycled. The remaining 75% is simply thrown away, which represents a huge waste of potential resources and major damage to the environment.
These figures come from a report published in 2018 by the European Environment Agency. Its statistics are the most recent available and are probably underestimated as they are based on 2011 data.
Turning waste into resources (or ‘turning waste into cash’, in the latest jargon) is one of the engines of a circular economy. When waste comes from biomass, it is part of a circular bioeconomy. The subject is explored in a recent article published in Advanced materials, one of the most influential scientific journals in materials science, and is featured on the inside back cover.
“In our group, we have considered waste and residues of all kinds as raw materials for more than a decade. We have carried out a critical review of the literature and repositioned the state of the art in strategies for converting agrifood losses and waste into bioplastics and advanced materials. We looked for arguments not to do this, but found none. It’s a win-win, ”said Caio Gomide Otoni, first author of the article. Otoni is a professor in the Department of Materials Engineering at the Federal University of São Carlos (DEMA-UFSCar), in the state of São Paulo, Brazil, and creator of a group called EQUIPMENT.
As an alternative to the more rustic and environmentally harmful recycling of agro-industrial waste as animal feed, for example, the study shows that biomass that is usually discarded or underused can serve as a low-cost feedstock. for bioplastics and advanced usable materials. in a wide range of high added value devices.
Applications range from multifunctional packaging with antiviral, antimicrobial and antioxidant properties to flexible electronic equipment, biomedical devices, power generation, storage and transmission equipment, sensors, thermal and acoustic insulation and cosmetics. , among others.
“The food-materials-energy link is very relevant for the circular bioeconomy. We set out to present the most advanced strategies to deconstruct agri-food waste, convert the result into monomeric, polymeric and colloidal building blocks, and synthesize advanced materials based on this, ”said Daniel Souza Corrêa, penultimate author of the article. Correa is a researcher at the National Laboratory of Nanotechnology for Agribusiness (LNNA), a branch of the Brazilian Agricultural Research Society (EMBRAPA) in São Carlos, and professor of chemistry and biotechnology at UFSCar.
The conversion of food losses and waste into advanced industrial “green materials” is an emerging policy option in the most developed countries, as illustrated by the European Green Deal. “The circular bioeconomy maximizes the use of secondary and residual streams from agriculture, food processing and forest industries, thereby reducing the amount of waste sent to landfills,” says the official European Commission. website in the program.
The article by Otoni et al. argues that if the stratosphere is viewed as a boundary, there is no “throwing”. Turning waste into useful resources is the rational alternative to covering the planet with waste.
“The complex and heterogeneous composition of biomass derived from food loss and waste poses technological and economic challenges,” said Otoni. “We have to address what we can call the ‘recalcitrance of biomass to deconstruction’. Another unfavorable factor is the seasonality of agro-industrial production. Certain types of waste are abundant at certain times of the year and rare at others. Even when they are available, their composition is generally variable. But the main obstacle to large-scale upcycling [creatively recycling materials into new products with more environmental value] is political in nature. The hope is that startups and highly innovative companies can overcome these obstacles and move the process forward.
The technological ways to do this exist, as the article shows. Its authors have already mastered them at the laboratory scale or, depending on the case, at the semi-pilot or pilot scale. “Several examples can be cited, including the production of waste materials from mango, banana, wheat and cashew nuts, among others,” said Henriette Monteiro Cordeiro d’Azeredo, also co-author and researcher at LNNA-EMBRAPA.
In the images at the top of this page, the materials resulting from the minimal processing of cores on a semi-pilot scale at LNNA illustrate the potential for converting food waste to bioplastic.
Researchers also produced antimicrobial foam from sugarcane bagasse, packaging containing chitin extracted from crustacean and insect exoskeletons, and emulsion stabilizing particles with potential applications in product manufacturing. pharmaceuticals, cosmetics and paints.
As can be seen, this research has strong affinities with the economy of a country like Brazil, the world’s leading producer of sugar cane and oranges, and the leading producer of many other food crops. It should also be remembered that a very important source of food loss and waste is associated with fruits and vegetables: around a third of the total quantity produced is lost throughout the chain.
“Much of the food loss and waste contains high levels of vitamins, minerals, fiber and protein, all of which could ideally be converted back into food,” Otoni said. “However, most are classified as inappropriate and rejected on the basis of microbiological and sensory standards. Hence the alternative of turning waste into chemical platforms and useful materials with potential applications in high added value devices. given the large and growing volume of food waste, agrifood producers are genuinely interested in upgrading these flows.
An example is the edible bioplastic developed by Luiz Henrique Capparelli Mattoso, one of the leaders of this line of research at LNNA-EMBRAPA. Research is carried out in a network, with contributions from dozens of researchers in this specific field. The other co-authors of the article are Bruno Mattos, researcher at Aalto University in Finland; Marc Beaumont, researcher at the University of Natural Resources and Life Sciences (BOKU) in Vienna, Austria; and Orlando rojas, director of the Institute of Bioproducts at the University of British Columbia in Canada.
According to Mattos, “The quality of building blocks obtained from waste biomass is the same as that of purer, less processed sources, such as cotton or pulp. However, the waste contains several other residual molecules, such as pectin and lignin, offering a wider range of properties that can be explored for the introduction of functionalities in bioplastics ”.
FAPESP funded this line of research through the following projects: 14 / 23098-9; 17 / 12174-4; 17 / 22401-8; 18 / 22214-6; and 20 / 11104-5.
About the São Paulo Research Foundation (FAPESP)
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