Chile-based startup Valnux has developed an alternative to plastic using walnut shells. Product design engineer Patricia Olave and chemical engineer Natalia Valencia founded Valnux to reduce waste in Chile. At the same time, they’re providing a unique solution to the global plastic pollution crisis.
To make the material, they grind up the shells and put them through a process used by the plastics industry. The result is a biodegradable thermoplastic that also possesses naturally occurring antibacterial and antimicrobial properties. Walnuts contain a special molecule called juglone. Juglone is a molecule naturally present in walnut shells that is well documented in scientific journals for its antibacterial and antimicrobial properties. However, few manufacturers exploit this characteristic to make useful materials, Olave said. The antibacterial and non-toxic properties have been proven to work as they were confirmed in microbiology laboratories.
In 2018, 12,000 tons of walnut shells were left in Chile—the second largest global exporter of the nut variety – which inspired Valparaiso-based start-up to turn this waste into organic raw material. Currently, a majority of this waste is burned as an alternative to firewood or used to replace groundcover in gardens. Instead, Valnux will use the waste to produce more than 30 plastic-free cutting boards from one hectare of walnut waste per harvesting season.
For now, the company is starting off with creating kitchen utensils such as cutting boards and fruit bowls. However, it is open to developing walnut-based bioplastic for other products, including food packaging, in the near future.
Olave told Foodnavigator Latin America:
We have different industrial possibilities for this material, but for food [applications] it is necessary to keep investigating properties like the permeability of gases or ultraviolet filtering. And to be coherent with the ecological purpose of Valnux, it must come from natural components.
The walnut plastic is compostable; it fully disintegrates and decomposes, and does not alter the organoleptic properties of the food. Once it’s time to throw it away, it can be recycled by subjecting the material to high temperatures.
