Development of a process for the automated heading and filleting of mackerel with a core temperature of below minus 1.5 °C using Japan-trim

Based on current information (2016), in 2015 about 300,000 tons of mackerel were landed in Norway. More than half of this volume (180,000 tons) was then dispatched unprocessed to Asia for further processing. Only about 2–3 % of the mackerel were filleted in Norway, which corresponds to about 7,000–10,000 tons. Due to market shifts towards high quality products, increasing labor costs in Asia and an increased use of by-products it is assumed that the market for mackerel fillets processed in Norway will grow steady in the next few years, which will lead to a share of 25 % of fillets processed in Norway in relation to the total quantity. This would correspond to about 75,000 tons of mackerel to be filleted in Norway. These numbers could grow even further should the catch quotas for mackerel increase in the next few years.

In order to guarantee a good level of freshness of the product over a long period, the Norwegian fishing industry has been seeking to first deep freeze the fish and only then to gently thaw them out in a controlled manner. Controlled thawing out ensures that the core temperature of the fish is below minus 1 °C during the entire process, the fish consequently remaining in effect frozen during the entire process.

The Norwegian fishing industry is constantly endeavoring to develop new sales markets for its products. In this process a possible new sales market for mackerel is in Japan, since the qualitative requirements for fillets in this market have been sharply rising for several years and the present producers, China and Vietnam, are having difficulties in meeting these increased quality requirements. At the same time, labor costs in these countries and costs for the transportation of the round mackerels are increasing fast. Both facts are making it very attractive for the Norwegian fishing industry to add more and more capacity to process the mackerels inland. This also opens a real opportunity for the Norwegian fishing industry with its high standards to establish its own products in the market and thereby generate new sales. At the same time the type of cuts required in the filleting process differ from the standard fillets.

Against this background there is a strong desire on the part of the Norwegian fisheries industry for suitable machines and processes which will put them in the position of being able to react to these future requirements of the market with the right concepts.

It is Baader's claim to find a solution that will still satisfy the Norwegian fish industry's high quality requirements for the end product. This is above all a clean cutting surface, combined with maximum yield.

At the same time the machine is to be capable of filleting the mackerel with the so-called Japan-trim, since a market for this exists which is to be supplied by the Norwegian fisheries industry.

The high throughput of fish (up to 150 fish/minute) leads in practice inevitably to a high cutting speed, which, combined with the high rigidity of the source product, can lead to problems in the filleting process. Due to the lower temperature of the fish in comparison with the current standard product the friction properties may also be altered, which under some circumstances makes modifications to the autofeeder necessary. In summary it can be said that the obtainable results will be seen to be heavily dependent on the condition of the commodity (for instance aging, gentle freezing and thawing). If the fish are not frozen in the stretched out state but have a ‘banana’ form, then it can be expected that the automatic input of the fish into the heading machine with the current autofeed concepts cannot be achieved without further development work going beyond the remit of this project. Likewise the heading and filleting of curved frozen mackerel is only possible to a certain degree. Therefore it strongly depends on optimizing the upstream processes such as the deep freezing of the commodity or installing an upstream sorting after the thawing out process so that only fish that are straight arrive at the filleting machine.

It is believed that for the vast majority of Baaders customers an upgrade kit for the processing of frozen commodities on existing machines would offer the greatest possible benefit in the short- and mid-term. Therefore such an upgrade kit is always favored in solving the problem.

In summary it is the aim of the project to design an optimal link in the process chain in processing frozen mackerel. The consistently high standards with respect to reliability, yield, quality and hygienic design are to be fully applied in this project so that the Norwegian fisheries industry can derive the greatest possible benefit from the newly emerging processing capabilities.