High yields from sophisticated equipment

Danish fish processing equipment manufacturers have for many years been at the forefront of developments in their field. As the world became more globalised Danish processors needed to automate their operations in order to stay competitive. Processing equipment manufacturers responded to this need, building machines that were increasingly sophisticated and that could run virtually with no or very limited human intervention. Now, in other parts of the world too, this expertise in automation is increasingly sought after.

This gutting machine is designed for salmon and salmon trout weighing 1.5 kg to 8 kg. It is particularly suited to handling fish with roe as the roe can be safely removed during the gutting process.

The fish processing equipment industry in Denmark has certain advantages. The labour force is highly educated, many products are developed by companies in close collaboration with their customers, the equipment is rigorously tested in the most demanding environments, and cooperation between companies and technical universities enables the implementation of up-to-date research. As a result the equipment tends to be sophisticated, robustly yet elegantly built, easy to operate – and expensive. The Danish fish processing equipment industry includes a range of companies both large and small, some producing equipment that can handle any processing operation for any species, others specialising in certain operations for certain species. One of the latter is the company Kroma based in Skive on Jutland, the Danish mainland.


Focus on primary processing

Kroma specialises in primary processing, that is, de-scaling, gutting, and filleting machinery for portion sized fish. Here, a de-scaling machine.

Since 1975 when it started, Kroma has focused on what its owner and managing director, Ivan Kristensen, terms primary processing, the basic processing operations, de-scaling, gutting, and filleting (including heading and tailing), for portion sized fish. This is a strategic decision the company has taken, to leave further processing operation to other manufacturers. The most common species for which Kroma’s machines are built include trout, seabass and seabream, tilapia, as well as mackerel and herring, and even salmon. Most recently the company sold one of its gutting machines to a factory in Thailand that was processing skipjack tuna to be canned. The factory wanted to reduce the labour intensity of the processing operation and automate this part of the process. It approached Kroma to see if they could provide such a machine, although tuna gutting machines are not in fact part of the company’s product line. However, as gutting in general is an area on which they focus, it was of interest to take on this project.

The solution lay in a machine that was fundamentally the same as a gutting machine for trout. But to use it for tuna called for extensive re-tooling, the frame and screens were the same, but the insides are completely different. Although being used in this instance for skipjack, the machine can be used for other varieties of tuna in the size range of 1-4 kg. This project is an example of the kind of service Kroma can provide. We will certainly consider something new, but only if it is falls within our area of competence, says Ivan Christensen, that is de-scaling, gutting, or filleting. If somebody asked us to build a packaging machine, we would decline.


Kroma has a lot of experience with trout having produced machinery for this species since 1975. Pictured, a gutting machine for small and medium enterprises.


Solid experience in trout processing

Kroma has developed, for example for trout, a series of machines that can be coupled together to take care of all the initial processing steps, that is de-scaling, gutting and filleting. Denmark is among the biggest farmers of trout in the EU, both in freshwater (36,500 tonnes of rainbow trout in 2010) and in cages in the sea (80 tonnes of sea trout) and Kroma has been producing equipment for trout since 1975, so “we have a lot of experience in that area,” says Ivan Kristensen. Mackerel is another species with which Kroma has a lot of experience, in particular gutting and filleting. Machines that perform these operations have been in demand in the Netherlands, where smokehouses supplying the domestic market as well as Germany have been important customers. The machines can be tailored to handle fresh or thawed raw material, which allows the customer a degree of flexibility. For example, Bond Seafood in Breda, Netherlands, a producer with a 250 year tradition in fish products, uses Kroma’s gutting and filleting equipment to prepare the mackerel before it is smoked.

Although many of the fish species for which Kroma’s equipment is intended are portion-sized fish it also is working with some customers to develop filleting machines for small fish like sprats and sardines. The equipment’s ability to handle different sized fish is continuously under development and tends to reflect the customer’s requirements and the country in which it is intended to work. Trout in Denmark for example used to range from 180 g to 7-8 kg, while in Turkey seabass and seabream are from 200 to 450 g. The machines when they are installed are adjusted for the outer size limits and then as each fish passes through the machine it is measured (the length and the height of the abdomen) and the measurements used to define the size of the fish and thereby identify the size of the head, and the position of the gills and the collarbone. This information is then used to adjust the positioning of the knives. The entire process takes place so rapidly that the bigger gutting machines can perform at a rate of up to 65 fish per minute. The way the system works means that a single machine can be optimised for different species and once the optimisation has been carried out for a particular species the size of each individual fish is of little consequence. The machines are also equipped with a sophisticated logging system that will keep track of how many fish are processed during the day, by which operator, the size of the fish, and the efficiency of the machine, among other details.

Tommy Brøgger, the owner of Ravnstrup Mølle, is completely satisfied with the Gutmaster 1200 he bought in 2009.


Turnkey solutions are also developed

While Kroma itself specialises in primary processing it can also offer turnkey solutions for a whole processing line. We work with other producers of equipment that can then be integrated with ours to give a complete solution if that is desired by the customer, says Mr Kristensen. The company also offers a roe handling system as an add-on to the gutting machine. While the gutting machine gently removes the roe sac from the body cavity, the roe handler can then separate the eggs from the row sac. So far this has mainly been used for processing trout.

Kroma’s machines are highly advanced. Clever software melds with sophisticated hardware to measure each fish and adjust the knives allowing a wide range of sizes to be processed on the same machine and eliminating the need to grade the fish before it is processed. The gutting machines clean the fish neatly and thoroughly and the filleting equipment is engineered to give a very high yield. After a couple of bad years in 2009 and 2010 brought on by the financial and economic crisis, companies have realised that this Danish company has something special to offer and business has picked up substantially. This year the company has sold three projects in Italy and is optimistic that if it can sell in Italy despite all the hardship there, it must be possible in other countries too.