Without it, the mussel could not cling to its proverbial rock: the byssus is not edible, but this little fibrous beard shell now bears the hopes for the development of the mussels of the Charente-Maritime.
Pet food, medicine, cosmetics industry … this filament rashed mercilessly by the mouclade amateur's knife, could well contribute to the rescue of a sector in difficulty.
It is precisely the mortality that has hit the mussels since 2014 that led the regional committee of the culture of molluscs Poitou-Charentes (CRC) to study the waste of mussels to find an economic parade. And the filament secreted by mussels to fix himself, the thread of fine linen, has kept all his attention.
The CRC has enlisted the La Rochelle agglomeration community, the Bordeaux Nutribrain laboratory, the agro-food group of Arrivé and the sister mussel association, with the Nouvelle-Aquitaine region, which financed part of the research.
Known from antiquity – cited in the Bible as a noble material of clothing worn by the merchants of Tire -, the byssus could advantageously supplant the imported soy meal to feed the poultry.
"It contains amino acids of better quality and in greater quantities than soy," says Charlotte Rhone, Project Manager at CRC. "Furthermore, it does not require large investments in drying".
– Laying of hens and surgery –
The agri-food company Arrivé-Bellanné is currently conducting tests and considers "smart to use". "It's very rich in protein," says AFP director Antoine Bretaudeau. "Its composition can be well adapted to organic laying hens".
For this use, the byssus would sell from 3 to 400 euros per tonne, estimate the CRC, which evaluates the annual departmental deposit to 700 tons.
The first production could arrive "in a year, at the end of the 2019 mussel season", think Sister's president, Stéphane Fournier.
But in the longer term, the sector can hope for much higher value-added sales points by focusing on the benefits of fine-grained on the human body.
Byssus contains in fact amino acids good for the skin and could affect the cosmetic industry. Here again the studies are under way.
It could also be used in food supplements for children, adolescents, pregnant women and athletes, who have high requirements for amino acids and proteins.
The president of the PS New Aquitaine Alain Rousset is sure: "tomorrow the new drugs will be born from the ocean".
Better yet, the adhesive able to adhere to a moist medium containing catechol could help to suture the organs in surgery.
One other track: it would also have benefits on the brain, against anxiety, depression, Alzheimer's disease and promoting memory.
"We study what it contains accurately and, based on the results, we can direct our research into brain function, because the omega 3 and some polyphenols protect against age-related cognitive decline," explains Anne-Laure Dinel, President of the Nutribrain laboratory in Bordeaux, specializing in the study of the impact of nutrition on brain well-being.
These perspectives still require "at least five years of research", the scientist insists. However, if they prove to be effective and profitable, Stéphane Fournier is convinced that the items stored could be worth "tens of thousands of euros per kilogram".
And the rest of the fine silk would come back to feed the chickens.