Automating & Maximising Fish Roe Extraction

Our latest case study focuses on an enquiry we received to supply five flexible impeller pumps to enable the smooth and hygienic transfer of fish roe suspended in water.

Our client specified that the pumps had to be capable of roe transfer at 36,000 litres per hour, while also operating slowly and gently to ensure that the fish eggs were not broken or damaged during the process.

What is fish roe?

Fish roe are the eggs which are collected from marine animals. It is high in nutrients and Omega 3 and are often used in dishes as a raw ingredient, or can be a very expensive delicacy - caviar.

All female fish have roe and these eggs can be sourced internally from two sacs - one on each side of the belly, or from an external egg mass. Fish roe can be taken from any type of fish like salmon, trout, cod, paddlefish or whitefish. The term roe also applies to eggs from other marine animals like scallops, lobsters and shrimp.

Is it the same as caviar?

All fish eggs are called roe, but not all roe is caviar. The term caviar only applies to fish roe from the sturgeon family, Acipenseridae. Salmon roe and the roe from whitefish, cod, trout, red caviar, ikura, tobiko and so on are considered caviar substitutes and not caviar.

Clearly, fish roe is a highly prized and very valuable commodity. Extraction, fish egg transfer and cleaning make this excellent product valuable for human consumption, as well as offering enormous opportunities for profitable use in other food production applications such as fish meal. 

This is why food companies are constantly looking for the most efficient, hygienic and streamlined method of extraction and roe transfer, to harvest the hidden value from these unique products.

Our client wanted to boost the efficiency of their fish egg transfer process, by automating extraction of the fish roe, to benefit from better roe handling, hygiene and quality. This would all help to maximise the economic value of the roe, as well as the return made on each fish.

Just one part of a complex extraction process

The pumps we specified would be a key component of an intricate extraction method which involves the automated process of separating the fish eggs from each other as well as the skin or sack they are attached to.

The roe is firstly gently separated from the sack, in which eggs can separate in clumps or individually. The eggs are gently stirred in a slowly rotating rotary separator to aid the separation of individual eggs and those which are broken. It is then washed several times to remove traces of the sack or broken roe and also to also desalt.

It can be additionally processed and mixed with other ingredients to create fish meal or other products and alternatively frozen, salted, dried or fermented to preserve for long term storage.

Our Roe Transfer Solution

Here at North Ridge Pumps, we’re not restricted to a single pump technology, so we can provide the best pump for a particular application and designed for the lowest lifetime cost. We use our expertise to offer a tailored solution, not something straight off the shelf.

Flexible impeller pumps are a great solution for viscous liquids, creams, gels and solid-laden fluids. They can transfer delicate liquids at slow speeds and ensure that they retain their consistency without the ingredients separating.

Able to self-prime up to 6m, up to 40m head and at 44,000 litres per hour means that these pumps are great for small applications requiring the transfer of sticky, gooey, oily, thick or creamy liquids.

Why was this pump technology selected for this application?

As the pump head consists of a simple rubber impeller rotating at slow speed, the vanes create small pockets which transfers the roe suspended in water gently, with very little damage. The pump operates as a cross between a positive displacement pump and centrifugal enabling a high flow at medium pressures to be achieved.

Its range of product benefits include:

• Versatility – Operating at different speeds to handle different fluid consistencies, either at full motor speed or reduced via an inverter or gearbox.

• Flexible Mounting – Works mounted in almost any position enabling mounting in almost any location on a machine

• Gentle pumping action ensures that the fluid remains unchanged, affected through shear by its working motion or breakages.

• Flow is non-pulsing enabling accurate flow measurement via a flowmeter.

• Easy to maintain & clean with a small number of parts, easy access via the front casing as well as full compatible with Cleaning in Place Systems.

• A range of accessories are available to tailor the pump to your particular process including carry handle, variable speed drive, trolley, flowmeter and hosing

• Pump heads available with a variety of process connections including BSP M, BSP F, RJT, Tricover, Triclamp to suit your specific process 

With the new pumps in place on the machine it meant that the fish processors now had an improved method and process for the sanitary and swift extraction of high value ingredients.

If you have a hygienic application requiring the transfer of sensitive fluids, solids or viscous sauces, and aren’t sure which pump to specify, speak to North Ridge Pumps to see how we can help.

For more information on Automating & Maximising Fish Roe Extraction talk to North Ridge Pumps Ltd