Imitation crab meat is a seafood product made by blending processed fish, known as surimi, with various texturizing ingredients, flavorants, and colorants. First invented in the mid 1970s, imitation crab meat has become a popular food in the United States, with annual sales of over $250 million.
Surimi is the primary ingredient used to create imitation crab meat. It is mostly composed of fish myofibrillar proteins. These proteins are responsible for the quintessential characteristic of surimi that makes imitation crab meat manufacture possible, namely the ability to form a sturdy gel. The gel can be shaped and cut into thin strips which, when rolled together, mimic the texture of real crab meat.
Although imitation crab meat was introduced in the United States in the early 1980s, the Japanese have been using surimi-based products for over 800 years. Traditionally called kamaboko, the first recorded surimi manufacturing procedure was found in a Japanese cookbook written in 1528. Commercial production of kamaboko products began on a small scale in the nineteenth century. However, modern manufacturing did not start until the twentieth century, when efficient methods of bulk fishing were developed.
The basic manufacturing technology that is used today was primarily developed in Japan between 1945 and 1960. During this time, scientists developed techniques that made large-scale surimi production possible. For example, better methods of preservation were developed, and consequently the shelf life of surimi products was extended. Additionally, the science behind the gel forming properties of the myofibrillar proteins was worked out, and many factors that contributed to its texture were discovered.
One of the major problems with surimi was that when it was frozen, it lost its gel forming properties. As scientists investigated this problem, they discovered that the incorporation of cryoprotectant materials such as sucrose and sorbitol protected the surimi from degradation during freezing. This was important because it allowed imitation crab meat manufacturers to use surimi which was produced days earlier. This development of the mid 1960s resulted in a tremendous growth of the surimi-based seafood industry.
The process of making imitation crab meat from surimi was invented independently by Y. Sugino and K. Osaki by 1975. Early production of this product in the United States began in 1983 by the Japanese company Yamasa Enterprises. As popularity of this product increased, other companies also began production, and by 1986 the market for imitation crab meat was $250 million. Ultimately, U.S.-based corporations took market share away from imported products and now export imitation crab meat to Japan.
Various ingredients are mixed together to make a product which has the color, taste, and texture of crab meat. The surimi used in the manufacture of imitation crab meat is most commonly processed from the Alaska pollock or walleye pollock. To a lesser extent, the New Zealand hoki is also used.
During the manufacture of surimi, various processing ingredients are added. Cryoprotectant materials such as sugar and sorbitol are added prior to freezing to prevent the degradation of the gel-forming properties of surimi. These ingredients also have an impact on the taste of the final product and help extend its shelf life.
While surimi gels provide structure, other ingredients are needed to help stabilize and modify its texture. One important ingredient is starch. It improves the texture and stabilizes the gel matrix. This is particularly important for the stability of the product when it is frozen. The amount of starch is usually about 6% of the recipe. Egg white is also added to the surimi to improve the gel structure. It has the ability to increase the gel strength and improve its appearance by making the surimi more glossy and whiter. Vegetable oil is also used to improve the appearance of surimi and modify its texture.
Flavoring is added to surimi to make it taste like crab meat. These flavorants can be natural or artificial, but typically a mixture of both is used. Natural flavoring compounds include amino acids, proteins, and organic acids, which are obtained through aqueous extraction of edible crabs. Artificial flavors can be made to closely match crab meat flavor and are typically superior to naturally derived flavorants. Artificial flavoring compounds include esters, ketones, amino acids, and other organic compounds. Additionally, seasonings and secondary flavorants are added to the meat to improve the overall flavor. Common ingredients include nucleotides, monosodium glutamate, vegetable proteins, and mirin.
The coloring for imitation crab meat is typically made using water insoluble compounds like carmine, caramel, paprika, and annato extract. By combining these and other ingredients, various shades of red, orange, and pink can be obtained. Before using the colorants, they are mixed in a surimi paste. This allows them to be easily applied to the imitation crab meat bundles.
In the manufacture of imitation crab meat, quality control tests are performed at various points. For example, the characteristics of the incoming raw materials are analyzed. Specific properties such as pH, percentage of moisture, odor, taste, and appearance are all evaluated. The quality of the incoming fish is also checked. Most important is the test for rancidity.
The quality of the surimi is also examined by testing various characteristics. The chemical composition is tested using laboratory methods. Such things as protein content, moisture, and lipid content are all checked. Also, visual assessment of the color and texture of the surimi gives an indication of quality, as does a pH test. Since the gel-forming ability of the surimi is paramount to its use in imitation crab meat, various tests are run to ensure that it meets minimum standards before it is used. Finally, imitation crab meat is susceptible to microbial attack. Therefore, manufacturers routinely test whether their products are contaminated.
The water left over from the manufacture of surimi is characterized as waste water. It is composed of many water-soluble substances, fats, and suspended particles. Environmental regulations require that manufacturers treat this water before returning it to the environment. This is done using such things as filters, centrifuges, and chemical treatments.
Future developments in the imitation crab meat industry are likely to be found in a few key areas. One important area of research has focused on the development of surimi from different kinds of fish. These would include fish that currently have low economic value and are quite abundant. Many of these new fish have more fat and different body chemistries than the fish currently used, so the challenge will be to improve the surimi that can be made using them. In the manufacturing area, a more continuous process is being developed. These processes result in better yields of surimi. Also, environmental concerns will lead to new technologies that will minimize the amount of waste involved in manufacture. Finally, new crab meat recipes aimed at improving the nutritional value of the product will be developed.
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— Perry Romanowski