Bio-based plastics show great potential
According to the Food and Agriculture Organization of the United Nations, approximately one-third of food produced in the world for human consumption gets lost or wasted. In North America and Europe, about 50 percent of that is wasted in the home, where expired or unwanted food gets simply tossed in the trash.
Waste at the retail level has been addressed by wrapping product in plastic packaging that protects and prolongs shelf life. The paradox is that it creates waste in other ways. Is it possible to reduce food waste without creating a wasteful byproduct? Researchers say it is.
Most of the plastic used today is made from crude oil, which contributes to CO2 emissions and pollution. There is an alternative, though, as researchers look for new ways to produce plastics from plant residues. In a talk at the most recent Fruit Logistica, André Lehmann, head of the fiber technology department at the Fraunhofer Institute in Germany, provided an overview of what’s available.
“Bioplastics must be an integral part of the realization of a sustainable packaging industry,” he said.
Some bioplastics offer great advantages to food processors, said Lehmann. Biopolymers based on polyester/polylactic acids, for example, offer excellent gloss, transparency and clarity. They keep in flavor and aroma, and are easy to shape, print and emboss. They also have better rigidity than some plastics, which means the packaging can be made lighter than ever before, he said. Most importantly, though, bioplastics offer more disposal options than conventional packaging. Many are biodegradable and/or compostable.
While there were many packaging companies on the floor at Fruit Logistica, one offered a variety of bio-plastic in-sleeve and flow-pack options: Mediane. Peter van Tolingen, general manager of Mediane North America, said the company entered the market to provide environmentally sustainable solutions for forward-thinking companies.
PLA bio-sleeves are produced out of renewable resources and offer degradability and compostability, Tolingen said. “We sincerely believe that our future depends on what we do in the present,” he said.
It isn’t just plastic that’s getting revamped: cardboard and paper products are seeing improvement too. Dutch tomato growers Duijvestijn Tomaten aims to lower its CO2 production to the point where it will be the country’s first CO2 consuming greenhouse grower. They started on a small scale, focusing on water use, nutrient cycling and energy consumption, eventually turning to geothermal energy as a possible solution.
Taking the business to the next level, they decided to tackle packaging. Today, Duijvestijn’s packaging includes paper made from tomato stems. They’re even looking for ways to use tomato leaves.
Developed in partnership with Solidus Solutions, the solid board from tomato plants won Packaging Europe’s Sustainability Award in 2016. Solidus Solutions said the innovation reduces CO2 emissions equivalent to driving 260 miles by car for each ton of board produced.
“We’ll try to use everything in the future,” said Ad van Adrichem, who is chiefly responsible for the cultivation of tomatoes and the geothermal project at Duijvestijn Tomaten.
Much work is being done to develop new biobased materials. Wageningen University in The Netherlands, for instance, is leading a research program on biobased performance materials. The program’s aim is to develop and improve biopolymers, the building blocks for biobased materials.
Work is even being done at the student level. Through Wageningen, a group of undergraduate students improved the properties of a bioplastic by incorporating nanoparticles of chitin. Chitin is a water-repellent, hard polymer made from the exoskeletons of arthropods. While bioplastics made of polylactic acids are usually brittle and permeable, the insertion of chitin made it more stable and stronger. For their efforts, the students not only won an award at a top chemistry competition for students, but they were also given €27,000 to work out a research proposal.
So what has slowed uptake of bioplastics? According to Lehmann, part of the problem is that the industry is in competition with oil-based polymers, which have had a 60-year head start.
“In principle, a bio-based chemistry is possible,” he said. “Pioneers do exist; pioneers are sought.”
Another issue could be cost. Bioplastics tend to come with a heftier price tag (see examples in the chart above).
“Real progress can only be made by price and performance advantages,” Lehmann said.
— Melanie Epp, contributing writer