During trials, real continent in crab legs is compared to what the spectroskopic light indicated. Photo: Nofima

Project Year 2017

Getting to grips with crab meat

 Raw materials and process optimisation    Seafood industry  

Determining how much meat is in crab legs the old-fashioned way is time consuming and inaccurate. We have developed a better way of measuring meat content.

The amount of meat in a king crab’s legs varies according to where it was caught and the season. To date, it has been hard to know which crabs have the highest meat content.

“Crabs are currently sorted manually – workers squeeze one or several of the crab’s legs to guess the meat content. This is time-consuming and not very accurate,” says Jens Petter Wold, a senior scientist at Nofima.

New method

Companies that make products out of king crab have long needed a way to reliably measure meat content and sort the raw materials.

“Rapid measurement will revolutionise sorting by meat content and setting of prices between fishermen and processing companies,” says Grete Lorentzen, a senior scientist at Nofima.

She is heading the Finnkrabbe research project, where businesses and scientists are working together to develop new, improved methods for processing snow crab and king crab. A main goal is to develop a rapid, non-destructive and accurate means of measuring meat content in fresh and live crabs’ legs. Using near infrared light (NIR) we can “see” inside the crab legs without harming them.


So far, the project looks very promising.

“We have tested various instruments, and achieved very good results with a NIR instrument that was originally developed to measure the fat content in whole salmon. Light is shone into a crab leg, and we measure the light that is reflected back, providing us with information about the water, fat and protein content. The measurement takes one second and will hopefully be of great benefit to the industry,” says Grete Lorentzen.

Large-scale industrial production

The team is now testing different methods to find the one best suited to large-scale industrial production.

“The measuring method that works best today requires the crab legs to be held up to a sensor manually. Ideally though, the industry would like a system that can be installed over a conveyor belt and automatically scan the crab legs that pass beneath. We hope to get there during the project period,” says Jens Petter Wold.

The scientists are working with Storbukt Fiskeindustri in Honningsvåg and Arctic Catch in Vardø – both significant players in the Norwegian crab industry. In addition to the meat measuring instrument, the project is also working on developing humane, ethical methods of stunning and killing snow and king crab. As well as ensuring animal welfare, it will also enable quicker, easier crab processing. Methods are also being developed to improve bleeding, cooking, chilling and freezing.

The scientists believe that an instrument that can measure meat content will have applications far beyond this project.

“Live storage of king crab, for example, which we expect to become increasingly common, with feeding to increase the meat content. This kind of instrument will be very useful to know when feeding can be stopped. It can also be used in live storage without access to food, to know how long crabs can be stored before the meat content is affected – which is priceless information,” says Grete Lorentzen.

The project is also looking at whether the measuring technique developed for king crab can be used to measure the meat content of the slightly smaller snow crab.


Nofima – Strategic Research Initiatives: Spectec

With a view to providing businesses with the expertise they need to deliver top-quality products, Nofima is developing world-class research in selected areas. Spectroscopy is one such area, and through the Spectec project, a Strategic Research Initiative headed by Jens Petter Wold, scientists are working to improve and develop new and better rapid measuring methods using light.


Storbukt Fiskeindustri AS, Arctic Catch AS, Optimar AS, Mattilsynet i Hammerfest

Norges forskningsråd

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