Foie gras, the rich and buttery French delicacy made from duck or goose liver, has long been criticized for its production method that involves force-feeding. The controversy has led to bans in several countries.
Now, a team of scientists says they have developed a more ethical alternative that mimics the traditional taste and texture, without the cruelty.
"It was always a dream to make foie gras more accessible and better for animal welfare," said lead author Thomas Vilgis, a professor of food science at the Max Planck Institute for Polymer Research in Mainz, Germany. "It's good to stop these force-feeding practices — or at least reduce them."
The findings, published Tuesday in the journal Physics of Fluids, detail how Vilgis and his colleagues from the Max Planck Institute and the University of Southern Denmark created the foie gras-like product using only natural components from the animal itself. They avoided any artificial additives.
Initially, they experimented with collagen from the birds’ skin and bones to create a liver-fat emulsion. However, the result lacked the signature silky texture of authentic foie gras.
The breakthrough came when they treated the fat with the birds' own lipases, which are enzymes naturally used to break down fat. This approach allowed the fat to crystallize in a way that replicated the formation of traditional foie gras.
"At the end of the process, it allows the fat to recrystallize into the large crystals which form aggregates like the ones we see in the original foie gras," Vilgis said.
According to the team, the process is relatively simple. They harvested the liver and fat, treated the fat with lipases, mixed and sterilized the result. Laser microscopy showed that the fat droplet size and emulsion structure closely matched traditional foie gras. Even the aroma was on point.
To test the texture, they used industrial food compression devices that gently pressed the samples to measure firmness.
"We could really see the influence of these large fat particles, which we call in the paper 'percolating clusters,'" Vilgis said.
"At the beginning of the 'bite,' these large clusters have a high resistance, creating a similar mouthfeel of elasticity — without being too rubbery like after the collagen or gelatin addition."
Vilgis has filed a patent for the process and is looking to partner with companies to bring the innovation to market.