Coextrusion of a fresh preparation with a vegetable casing
A coextruded sausage with a vegetable casing resembles a regular sausage. The skin is an entirely edible vegetable alternative. The process requires attention throughout the forming, coating, and drying operations.
The core is made of meat, fish, cheese, or vegetable-based compounds.
The coating is prepared with the following:
- A hydrocolloid such as an alginate
The fluid slurry is set using the following:
- A calcium salt
Optionally, the coating film can be mixed or further coated with the following:
- A spice coating
- A smoke flavour
How does it work?
The coating occurs by forming a film, which is set by a reaction with calcium salt, which polymerizes it.
The thickness and firmness of the alginate film result from the respective hydrocolloid and salt proportion in water.
It is a continuous operation. Speed is adjusted to balance firmness and softness for cutting and closing the edges.
Forming of the core material into a mostly round, sausage-like, cohesive rope
Simultaneous coextrusion with a fluid alginate-based film
Combination or immersion into a solution of calcium salt
Draining of the coated rope optionally
Cutting into portion, partial drying
Upstream: The sausage mix is prepared in a vat, mixer, and mincer machines.
The coating occurs in a former sausage adapted with a coextrusion head or device to apply a film all around the core shape.
Downstream: After coating, the product is partially dried to give it a firm texture.
The coating system fulfills several operations in one pass :
- Forming the sausage mass into a cylindrical string
- Coextruded a fluid alginate film around the string
- Immersing the coextruded string in a calcium salt bath where the alginate sets
- Gently pulling the string, pinching it, and arranging it in a chain for subsequent drying
This is a continuous operation.
How do you measure your success?
Key quality features
The product is fresh and has an inconstant definition.
No bumps, roughly cylindrical shape.
No cracks and leaks.
The solidity of the casing.
Key quality parameters
There are multiple factors to play with.
Specific taste, texture and rheology.
Alginate quality, use of inclusions.
Residence time, and constant calcium concentration of the reaction bath.