Surimi

What is surimi?

Source:http://www.billionfish.com/product.asp?pid=4

Surimi is originated from Japan word which refers to minced fish flesh that have undergone a few times of leaching process and addition of additives. Raw materials for surimi production are mostly underutilized fish species. Surimi is deboned and minced fish meat that has been washed of water soluble, lipids, or sarcoplasmic proteins and other impurities. Alaska pollock (Theragra chalcogramma) is the premium fish species for production of surimi seafood products. This is due to the high nutrient content, low fat and low cholesterol content of surimi seafood which make them continues to grow in recent market.

History

The process in making surimi has many history and origins. In Japan, it was used in the making of kamaboko, fish sausage or cured surimi products. The Surimi-making process was then refined in 1969 by Nishitani Yosuke of Japan’s Hokkaido Fisheries Experiment Institute to process excess increased catch of fish and to revive Japan’s fish industry. In the early 1960s, surimi industrial technology was developed by Japan to promote the growth of the surimi industry. The growth of the surimi industry was based on the Alaska pollock. But the production of surimi from Alaska pollock surimi declined and was supplemented by using other species.

Source:http://surimischool.org/wfc2016

Amounting 2-3 percent of the world fisheries’ supply which denote about two to three million tons of fish from around the world are used for the surimi production and surimi based-products. The major producers of surimi are Unites States and Japan. Thailand also has become an important producer. Malaysia ,France, Faroe Islands and Vietnam are the newcomers to the surimi industry.

Source:http://surimischool.org/wfc2016

For more information about how surimi is made, please click the link below:

Surimi Production Line

The surimi is made from the fish meat then rinse numerous times to eliminate undesirable odors and the compositions of differing proportions of additives such as starch, egg white, salt, vegetable oil, humectants, sorbitol, sugar, soy protein, seasonings, and enhancers such as transglutaminases, monosodium glutamate (MSG) and addition of ω -3 PUFA-rich oils (flaxseed and salmon oils). When the surimi is to need to be packed, the cryoprotectant (4% Sucrose,4-5% Sorbitol, 0.3% Sodium Tripolyphosphate and 0.3% Tetrasodium pyrophosphate) are added before freezing as preservatives to protect biological tissue from freezing damage.

Why cryoprotectant so important?

The cryoprotectant enhance the stability of proteins by shifting the equilibrium from unstable conformation to stable state which known as Solute Exclusion and also facilitating the formation of ‘glassy state’ upon freezing. The additives are used to stabilize surimi proteins by reducing the rates of deteriorative reactions by preventing introduction of metal ions and chelate them with added phosphates and minimize exposure to oxygen by creating GLASS state by storing them below glass transition temperature which the solute interactions ‘lock’ the structure, immobilizing the solvent (water), thus effectively stopping most reactions such protein denaturation and aggregation. Cryoprotectant also lowering the molecular weight of sugars and polyols. This can enhance hydrophobic bonds within protein molecules which stabilize their native (folded) state to denaturing forces. There is also another way which using cryostabilizers in high molecular weight polymers. This will increase the glass transition temperature, such that storage at normal freeze temperatures will result in the system being glass + ice. 

The ω -3 PUFAs may loss when the fish is processed into surimi but the ω-3 oil is added to overcome this problem. The surimi that incorporated with ω-3 PUFAs may provide a better alternative to direct ingestion of dietery supplements, other major change in dietery habits and medications. But ω -3 PUFAs may lead to rancidity, texture ,color deterioration, increased lipid oxidation and loss of nutrients. Surimi which is high in ω-3 PUFAs may aid in weight loss and help fight inflammation.

In addition, the polymerization of myosin when heated is how to cure the fish paste. Many pelagic fish with higher fat contents lack the needed type of heat-curing myosin and are not used for surimi. It was an industrial practice to add bovine blood plasma into the fish paste to help its curing or gel-forming, before the outbreak of bovine spongiform encephalopathy (BSE, mad cow disease). Today some manufacturers may use a transglutaminase to improve the texture of surimi. Although illegal, the practice of adding borax to fish balls and surimi to heighten the bouncy texture of the fish balls and whiten the product is widespread in Asia.

Conclusion

In nutshell, the cyoprotectant plays an important role in surimi production due to its benefits and even nowdays, the consitution of surimi has been analyzed to improvize the shelf life and its texture to increase the appearance of surimi without having the side effects for the products when keep them for a longer time .

References:

1. Santana,P.H.N.a.Y.T.A., 2012. Technology for production of surimi powder and potential of apllications. International Food Research Journal, 19(4),pp. 1313-132
2. Dey, S.S., Dora, K.C. (2011) Suitability of chitosan as cryoprotectant on croaker fish (Johnius gangeticus) surimi during frozen storage. Journal of Food Science Technology. 48(6):699-705.
3. T. Bourtooma, M. C. P. J. R. S., 2009. Recovery and characterization of proteins precipitated from surimi wash-water. LWT - Food Science and Technology, 42(2), pp. 599-605.