Extrusion of feed for fish and shrimp - Pilot scale

Pilot scale extrusion of feed for fish and shrimp

At Danish Technological Institute (DTI) you can develop your recipes for fish and shrimp and test new ingredients or additives in our versatile pilot plant.

Extrusion is widely used in the non-food manufacturing industries to produce specialized shapes such as plastic components and aluminum sections. In the feed and food industry extrusion is fundamentally the same, with a number of variations. Extrusion (cooking) is used to produce human foods as diverse as expanded snacks, breakfast cereals, pastas, and textured vegetable protein. In the pet food industry, extrusion is used to produce dry and semi-moist food for animals.

To extrude fish feed is a process that converts raw material into a product with desired shape and form by forcing the material through a small opening using pressure. The process involves a series of unit operations such as mixing, kneading, heating, cooling, shaping, and forming. The process is considered an HTST (High-Temperature, Short-Time) process in the food and feed industry.

Fish feed has been produced by extrusion since the 1960’s, and later on shrimp feed is also produced with extrusion.

Extrusion of fish feed gives several advantages such as:

High hygienic quality
Increased digestibility of starch and protein
Large amounts of oil can be added to the extrudate using vacuum coating, which is especially used in feeds for Atlantic salmon and Rainbow trout
Designed feed for specific species or conditions. The feed can be sinking, floating, vary in protein, fat, fibre, and carbohydrates and so on.

Development of extruded feed for fish and shrimp

At DTI we provide guidance in all phases of extrusion and offer facilities, equipment, and expertise that gives your company access to qualified process and product development. This enables quick and flexible assistance in developing, optimizing, and testing new ingredients and fish feed. We are approved by the competent Danish authorities for production and can work with raw materials such as insect meal and poultry meal.

Test productions (40 kg/hour) for research use

Based on your needs we can help you design your products and identify the right ingredients. From this we can produce for example:

Extruded fish- and shrimp feed for trial use
Technical samples for stability tests of ingredients such as antioxidants, enzymes, and vitamins
Smaller batches of niche products.
At our facilities, we have mills, mixers, extruder, dryer, and vacuum coater that enable us to work with several aspects of aqua feed. We can purchase basic raw materials for tests.

The extruder (Werner & Pfleiderer, Type Continua 37) is a double screw extruder, and equipped with a 7.5 kW engine. The extruder is very versatile, and it has a number of possibilities for changing parameters. These can be the screw configuration or the die design.

Documentation of the production process

At DTI we record the main parameters from the extrusion process and can make a technical report showing the results.