Each year in Europe, the food industry discards millions of tonnes of vegetable residue and legumes. In Italy, scientists are using these leftovers to make bioplastics, an innovative and ecological material.
Non-marketable by-products of legumes such as peas, beans or other lentils, are experiencing a new life.
Manufacturers tend to get rid of them despite the fact that they’re rich in proteins and fibers and still have nutritional value.
Within the framework of a European research project, a method has been developed to transform them into bioplastics. After washing, the vegetal waste is ground and then mixed with a special solution.
Eleonora Umiltà, chemist, SSICA:
“The proteins are made soluble in a buffer solution. Then there is a separation phase between the liquid part and the solid, fibrous fraction.”
The fibers can be used to make composite materials, while the proteins will serve as the basic ingredient of a future bioplastic.
“The final protein extract may contain some residual salts, but the percentage of proteins is very high, around 80%.”
Simona Bronco, technical manager LEGUVAL project / Institute for the Chemical and Physical Processes, IPCF:
“Purity, especially for the protein component, is important as it helps improve the performance and characteristics of the final material, the bioplastic.”
The result is a renewable resource – unlike oil, which is primarily used. The fields of application envisaged are varied: from food packaging to agriculture.
“This is one of the polymers that we use in the mixture, as well as proteins and fibers. Through the hot mixing process we get granules like this.”
These granules were produced by another research centre, a project partner in Slovenia. It’s here too, in a small family business, that bioplastics were first used to make recycled flowerpots.
The granules are melted before being injected into a mold. These pots are fully biodegradable and compostable, giving nutrients to both soil and plants.
Eva Štraser, Bokri D.O.O., co-owner:
“The material is biodegradable in a home compost. So if you don’t need it anymore you throw it in the home compost; or even better, you put it in the soil, and, in the soil, after three to four months, it decomposes.
“We first made samples of 1,000 pieces, we saw the production is OK. And now we are intensively looking for the right customers, for ecofarmers, for people who don’t want to waste all the plastic parts.”
The future looks promising for bioplastics and these ecological pots. Much innovation is expected, particularly in the sectors of agriculture and food packaging.