Concentrated in its buds, roots and hulls, walnuts contain an organic and at times, toxic compound called juglone. The yellow, crystalline substance acts not only as a natural herbicide but has also shown utility as a food coloring agent and as a textile dye.

Through technological development, Chile's Center for the Studies in Healthy Foods (CREAS) hopes to push the utility of juglone and innovate products to benefit the agricultural and pharmaceutical sectors.

CREAS researcher Carmen Soto explained to www.freshfruitportal.com that the idea for the project arose a few years ago to find new uses for discarded nut shells that may otherwise go to waste.

"This idea formed a few years ago, considering that nuts are among the most marketed products in Chile. We realized that in the majority of cases, walnuts are exported without shells, leaving waste with no use," Soto said.

"Speaking with walnut farmers and producers, we realized that there is a lot of peel, which is the external shell that originally has a green color and later becomes dark. It is used mostly for pigments."

Soto and her team hope to develop a technology to extract juglone, as well as the shells' other useful compounds such as phenols and other antioxidants.

"For producers, this will mean that residue will stop being a byproduct and can give added value. They will have to decide if they would rather throw out the waste or generate a new processing line," Soto said.

As organic production gains greater momentum, Soto pointed out that a natural pesticide developed from juglone could offer an alternative to chemical applications.

"If we are able to determine that the product has anti-carcinogenic characteristics, it will also be interesting for the pharmaceutical industry," she said.

The project will be supported by funding through Chile's Technological and Scientific Development Fund (Fondef).

www.freshfruitportal.com