If you have ever wondered why a fish stick should be crab flavoured, then welcome to the world of surimi.
In a formal sense, surimi is a deboned and washed fish paste for manipulation into other shapes, although other animal meat is apparently used. You could also describe it as a type of fish protein gel.
It is firmly in the Japanese tradition and quite a speciality product. The meaning is Japanese for ‘ground meat’ which leaves a great deal but not too much for the marketing exec. to worry about working on.
Surimi is often used for the preparation of traditional gels such as ‘kamaboko’, fish balls and sausages, fish steaks, fish cakes and even fish noodles amongst other various seafood products. In fact, surimi comes in many shapes and forms as well as crabsticks. It was originally intended as a mimic for shellfish and crustaceans like lobster and crab, and shellfish as well. We Westerners are wholly familiar with imitation crab in the form of crabsticks but might see it labelled or described as mock crab, seafood sticks or seafood extender even. In the UK, it has become legally more accurate to call the surimi seafood sticks to avoid trading standard issues especially when a crab has been no where near the stick.
Sushi often contains pieces of crabstick. Look at a Californian roll and you will see pieces of crabstick.
Production of Surimi
Surimi is a fish protein gel. These are primarily the myofibrillar proteins, the muscle proteins recovered by washing minced fish. That washing process removes any soluble fish materials including sarcoplasmic proteins and various impurities (Park, 2013).
Commercially, it is produced in at least 20 countries . The USA, especially Oregon is now the leading manufacturer followed by Thailand, Korea and South America. The US produces about 200,000 tons every year. Japan is not so predominant now but thy have not lost their appetite for this type of product. It is an effective method for using spare cuts.
The cost of surimi is estimated at 20 to 30 cents per ounce which compares favourable with lobster meat which is $3.20 per ounce.
The East Asians have been producing surimi for centuries and the history as to when it started is now lost. The Japanese consider it a delicacy from nearly 1,000 A.D. Possibly the Chinese started the idea off because they made fish balls and various imitation food for a thick soup known as ‘geng’. Geng is found in Fujian cuisine. The Japanese then developed the process further producing something called kamaboko along with fish sausage and even cured surimi products.
The commercial process was developed by a Japanese chemist who was able to preserve surimi with carbohydrate which meant its shelf-life was considerable extended.
The best quality fish is used – neutral tasting both in flavour and aroma, always white-fleshed and non-fatty. Alaska Pollock (Theragra chalcogramma) produces the optimum quality as its cheap. We also find Atlantic cod (Gadus morhua), bream, milkfish, all sorts of sharks, Tilapia and various Black bass have all been tried. Some fatty fish such as sardine is used in Japan for traditional fried kamaboko.
Functional Properties
Surimi has excellent binding, gelling and emulsifying capabilities and so finds its way as a functional protein for meat, fish, sausage, pasta and snack foods. It is composed of myofibrillar proteins.
Surimi is dependent on the type of fish muscle used in its production. The main but unused group, the sarcoplasmic proteins which are very soluble do not contribute much if anything to gel formation. In some cases they prevent production of good surimi especially if the proteases are still active as they will breakdown any structural protein in their vicinity.
The major structural proteins are myosin and actomyosin.
To make a crab stick is a relatively involved process. Cheap, white-fleshed fish is washed to remove any residual smell. It is ground to a paste which is gelatinous in appearance before various ingredients like salt, emulsifiers are added.
Cryoprotectants are often added to minimize protein damage through denaturation especially when its stored frozen. This process, devised by the Japanese uses 4% sucrose, 4% sorbitol and 0.3% sodium phosphate (Park et al., 1988). Increasing the level of cryoprotecting agents adds extra sweetness to the crab stick. In fish, this is a highly undesirable attribute (Baute, 1994).
References
Baute, S. 1994. Personal communication. Pfizer, Inc., New York, NY. Cheng, C.S., Hamann,, D.D.,
Lee, C.M. (1984). Surimi process technology. Food Technology, 38, pp. 69-40
(2013). Surimi & surimi Seafood ( 3rd ed.). New York, NY: CRC Press.
Park, J.W., Lanier, T.C., and Green, D.P. (1988) Cryoprotective effects of sugar, polyols and/or phosphates on Alaska pollock surimi. J. Food Sci. 53: 1-3.
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