Professor Thomas Vilgis and his team Max Planck Institute for Polymer Research, as well as researchers from the University of Southern Denmark, have developed a more ‘ethical’ way to create the dish.
Published in science journal Physics of Fluids, by AIP Publishing, initial tests involved adding cooked collagen from the bird’s skin and bones to the liver and fat emulsion after it was harvested, but the end product did not have the correct consistency.
Mimicking the natural process
It was then that the researchers came up with the idea of treating the fat with the bird’s own lipases – enzymes that help digest fat in the body – to mimic the activities that occur naturally in the duck’s body.
The liver and fat are harvested from the duck or goose, with the fat is treated with lipases before the two are mixed and sterilised.
“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,” said Vilgis.
The process creates a product with a structure and smell like foie gras, and subsequent stress-deformation test found it had a similar mouthfeel to the original, due to its mechanical properties.
A satisfying ‘bite’
“We could really see that 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 as after the collagen or gelatine addition.”
Vilgis has already filed a patent for the recipe, with hopes to partner with companies interested in helping scale up the production. He also wants to work with sensory scientists who can help refine the taste and smell of the foie gras.
“Everything in our process is controlled, which is a positive thing,” Vilgis concluded. “We never considered adding anything additional to the foie gras, because we wanted pure duck – nothing else.”
Meanwhile, polling last year revealed that the vast majority of people in the UK support the introduction of foie gras import ban.
