APPLICATION

Coextrusion of a fresh preparation with a vegetable casing

A coextruded sausage with a vegetable casing has the aspect of a regular sausage. The skin is a fully edible veggie alternative. The process requires attention throughout the forming, coating and drying operations.

Updated Aug 08, 2021 - 10 min Read

BASE

Core products

The core is made of a meat, fish, cheese, or vegetable-based compounds.

RECIPE

Ingredients

The coating is prepared with:

  • Water
  • A hydrocolloid such as alginate

The fluid slurry is set by means of :

  • A calcium salt

Optionally, the coating film can be mixed or further coated with:

  • A spice coating
  • A smoke flavour
  • Inclusions

PROCESS

How does it work?

The coating occurs with the forming of a film and its setting by a reaction with calcium salt which polymerizes it.
The thickness and firmness of the alginate film results 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. The coating sequences run as follows:

1.

Forming of the core material into a mostly round, sausage-like, cohesive rope

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2.

Simultaneous coextrusion with a fluid alginate-based film

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3.

Combination or immersion into a solution of calcium salt

4.

Draining of the coated rope optionally

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5.

Cutting into portion, partial drying

PROCESS

Coating system

Upstream

The sausage mix isprepared in vat, mixer, mincer machines.

Coating occurs in a former for sausage which has been 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.

PROCESS

Coating system

 The coating system actually fulfulls several operation in one pass :

  1. Forming the sausage mass into a cylindrical string
  2. Coextruding a fluid alginate film around the string
  3. Immersing the coextruded string in a calcium salt bath where the alginate sets
  4. Gently pulling the stirng, pinching it and arranging it in a chain for subsequent drying

This is a continuous operation.

PRODUCT EVALUATION

How do you measure your success?

Key quality features

The product is fresh and with versatile definition

Core

No bumps, roughly cylindrical shape

Casing

No cracks and leaks

Stability

Solidity of the casing

Key quality parameters

Multiple factors to play with

Core product

Specific taste, texture and rheology

Casing

Alginate quality, use of inclusions

Operation

Residence time, constant calcium concentration of the reaction bath