Fiberized Products: How Surimi Creates Imitation Seafood

Walk into any supermarket seafood section and you’ll likely find crab sticks, imitation scallops, and other shellfish-style products at a fraction of the cost of the real thing. These are fiberized products – also called analogue products – made from surimi, a refined fish protein paste. They are engineered to replicate the appearance, texture, and taste of expensive shellfish like crab and scallop. Understanding how they are made reveals a precise, science-driven manufacturing process that bridges affordability with culinary appeal.

What are fiberized products? 🔗

Fiberized products are a category of surimi-based seafood that simulate high-value shellfish items. According to ScienceDirect, surimi is a stabilized fish myofibrillar protein that originates from Japan, and its processing – including comminution, sheet extrusion, cooking, cooling, slitting, and bundling – forms the backbone of fiberized product manufacture. Unlike regular fish cakes or kamaboko, fiberized products specifically aim to mimic a target shellfish in fiber structure, color, and flavor. The most commercially significant examples are crab analogues (commonly known as crab sticks) and scallop analogues.

MadeHow.com notes that imitation crab meat was independently developed in Japan by 1975, with early U.S. production beginning in 1983. Since then, the product category has grown into a global industry worth hundreds of millions of dollars annually. The reason for this commercial success is straightforward: fiberized products make shellfish flavors and textures accessible to a far wider consumer base, regardless of geography or season.

Ingredients used in fiberized products 🔗

The formulation of fiberized products goes well beyond surimi paste. Each ingredient plays a specific functional role. According to fisheries product literature, the core ingredients include surimi, salt, starch, egg white, shellfish meat, shellfish flavoring, flavor enhancers, and water.

Starch is particularly critical – typically comprising around 6% of the recipe – because it improves gel texture, stabilizes the matrix during freezing, and, importantly, controls surface stickiness during bundling. As noted in research published in ScienceDirect, the starch-based binding agent on the outer surface of surimi filaments is key to maintaining the fibrous structure of the final product. Egg white increases gel strength and gives the product a whiter, more appealing appearance. Salt extracts myosin proteins from surimi, which drives the gel-forming reaction essential for texture development. Shellfish flavoring – which can include natural extracts from crab or scallop as well as artificial flavor compounds – recreates the characteristic taste of the target seafood.

The fiberized product manufacturing process 🔗

The production of fiberized products follows a logical sequence, with each step building on the last. Here is how the process works from start to finish.

Step 1: Tempering the surimi 🔗

Frozen surimi blocks cannot be processed directly. The first step is tempering – a controlled adjustment of the surimi’s temperature and moisture content to bring it to an optimal working condition. Safe Food Factory describes heating surimi to around -4°C, a temperature high enough to allow cutting while cold enough to prevent microbial growth. Tempering is critical: if the surimi is too cold, proteins won’t interact correctly in later stages; if it’s too warm, they may begin to denature prematurely and compromise gel quality.

Step 2: Pre-flaking 🔗

Once tempered, the surimi blocks are broken down into coarse flakes using a pre-breaker or flaking machine. YUKE’s crab stick production guide explains that this step, performed under low-temperature conditions in a bowl cutter, creates a uniform particle size that allows subsequent ingredients to mix evenly throughout the batch. Pre-flaking directly affects the homogeneity and final texture of the product: uneven flaking leads to inconsistent mixing and patchy fiber formation.

Step 3: Comminuting with ingredients 🔗

Comminution is the mixing and chopping stage where the pre-flaked surimi is combined with starch, salt, egg white, shellfish flavoring, flavor enhancers, and water. MadeHow describes this as a process carried out in a stone bowl grinder, producing a thick, homogenous surimi paste. During comminution, salt extracts myosin proteins from the fish muscle, forming an actomyosin gel network that will give the final product its characteristic firmness and elasticity. Starches are typically pre-mixed with water and added as a liquid suspension, while egg white and flavors are incorporated at the final mixing stage. Crushed ice is added throughout to keep the mixture temperature low and prevent premature protein denaturation.

Step 4: Forming sheets 🔗

The finished paste is extruded through specialized sheet-forming equipment into continuous, flat sheets of controlled thickness. YUKE’s production guide notes that the paste is spread and rolled before passing through alignment rollers, which orient the protein structure in a way that allows the final product to pull apart like natural shellfish. Sheet thickness is a critical variable – it must be uniform to ensure even cooking and appropriate texture. The alignment of fibers at this stage is what creates the layered, separable quality that consumers associate with real crab or scallop meat.

Step 5: Cooking the sheets 🔗

The formed surimi sheets are cooked – most commonly by steam – to permanently set the protein gel structure. ScienceDirect’s surimi overview explains that classical surimi cooking often involves a two-step process: a low-temperature setting phase (where endogenous transglutaminase strengthens the gel network) followed by a higher-temperature cooking phase that fully sets the proteins. Steam cooking ensures even heat distribution, preventing the tough or rubbery texture that results from over-coagulation. Cooking also eliminates food safety concerns and locks in the flavor compounds incorporated during comminution.

Step 6: Slitting 🔗

After cooking and initial cooling, the sheets are passed through a thin-cutting machine equipped with precision blades. According to YUKE, blade spacing is typically adjustable between 0.6 and 1.5 mm, producing fine ribbons or strands from the cooked sheet. The direction and spacing of cuts must be carefully controlled: cuts made in the correct direction relative to the sheet’s fiber alignment produce realistic-looking strands, while cuts at the wrong angle result in unnatural-looking pieces that fail to mimic real shellfish.

Step 7: Bundling 🔗

The individual strands from the slitting step are gathered and compressed into continuous bundles that replicate the multi-fiber structure of natural shellfish meat. Safe Food Factory describes one bundling method in which strands are rolled diagonally into a rope on a conveyor belt, with the travelling sheet peeling off the conveyor surface as it is bundled. The adhesion that holds fibers together in the bundle does not come from new protein-protein bonds (since proteins are already heat-set) but rather from the stickiness of the sheet surface controlled by the starch content – a detail highlighted in the IGNOU surimi unit.

Step 8: Coloring 🔗

Coloring is applied to give the analogue product its recognizable appearance. YUKE’s guide explains that food-grade coloring is sprayed or rolled onto the surface, and some manufacturers wrap bundles with a thin colored film for stability. Colorants such as carmine, paprika, caramel, and annatto extract are used to achieve shades of orange, red, or white, as described by MadeHow. One common technique involves applying a thin layer of colored surimi paste to one side of the sheet before or during cooking by co-extrusion, ensuring the color is bonded to the product rather than just superficially applied. This produces the characteristic white interior and orange exterior stripe familiar in crab sticks.

Crab analogues 🔗

Crab analogues are the most widely produced fiberized product globally. Wikipedia’s surimi article notes that imitation crab products were developed in Japan between 1973 and 1975 and subsequently became a gateway to international surimi consumption. The target texture for crab analogues is a delicate, flaky, fibrous structure with a mild sweetness and the characteristic aroma of crab meat. This is achieved using the full sheet-slitting-bundling sequence described above, with the sheets extruded at a moderate thickness. The final rope is wrapped in a colored film, heat-sealed, and cut to length – typically around 7 cm – to produce retail-ready sticks. In the United Kingdom, Wikipedia notes, labeling regulations now require these to be sold as “seafood sticks” rather than “crab sticks,” since they contain no actual crab.

Scallop analogues 🔗

Scallop analogues follow the same fundamental process as crab analogues but with important modifications. The IGNOU surimi unit states that the surimi sheet extruded for scallop analogues is wider and thicker than for crab analogues. This wider, thicker sheet is necessary because the final product must have the substantial, cylindrical depth of a scallop disk rather than a slender stick. The wider sheet results in a product of greater diameter after bundling, which is then shaped or cut to produce the round, flat scallop form. Flavor compounds that recreate the sweet, briny character of scallop – including scallop extracts, amino acids, and nucleotides – are incorporated during the comminution stage. The firmer, more cohesive texture of a scallop analogue requires careful control of the cooking step, as scallops have a denser mouthfeel than crab meat.

Freezing and packaging 🔗

After cutting to final dimensions, fiberized products must be frozen rapidly to preserve their color, texture, and structural integrity. The IGNOU surimi unit emphasizes that slow freezing causes large ice crystal formation, leading to excessive drip loss after thawing and a yellowed, translucent appearance that makes the product commercially unacceptable. Products are therefore passed quickly through the critical ice crystal formation zone (between -5°C and -10°C) using contact plate freezers or cryogenic freezers. YUKE’s guide notes that Individual Quick Freezing (IQF) locks in freshness and preserves the product’s texture for export markets, while vacuum or modified atmosphere packaging prevents oxidation and microbial growth during storage.

Why fiberized products matter in the food industry 🔗

Fiberized products address a genuine gap in seafood accessibility. Premium shellfish like crab and scallop are subject to seasonal supply, geographic limitations, and significant price volatility. Surimi-based analogues, by contrast, can be manufactured year-round from abundant white fish species such as Alaska pollock – the most widely used surimi base, as described by Trans-Ocean Products – and delivered with consistent quality at a predictable cost. They also offer a longer shelf life, easier portion control, and ready-to-eat convenience that fresh shellfish cannot match. For foodservice operators – from sushi restaurants to airline catering – fiberized products provide a reliable, cost-effective way to incorporate shellfish flavors into menus at scale.

Emerging manufacturing technologies are also expanding what fiberized products can achieve. Research published in ScienceDirect demonstrated that coaxial extrusion 3D food printing can successfully fiberize surimi, with a 12% potato starch coating producing the best gel stability and authentic tearing behavior along filament lines – pointing toward even greater precision in analogue product manufacturing in the future.

What do you think? Given that fiberized products like crab and scallop analogues closely replicate the taste and texture of the real thing at a significantly lower cost, do you think they should be more prominently labeled as fish-based products in restaurants and sushi menus? And as 3D food printing technology matures, how might it change the way we think about the boundary between “real” and “analogue” seafood?

References

1. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/surimi
2. https://www.madehow.com/Volume-3/Imitation-Crab-Meat.html
3. https://www.slideshare.net/slideshow/preparation-of-surimi-and-minced-based-fishery-products/238294854
4. https://www.sciencedirect.com/science/article/abs/pii/S1466856421001120
5. https://www.safefoodfactory.com/en/knowledge/62-surimi-imitation-crab/
6. https://fishcutting.com/crab-stick-production-process-steps/
7. https://egyankosh.ac.in/bitstream/123456789/9839/1/Unit-5.pdf
8. https://en.wikipedia.org/wiki/Surimi
9. https://trans-ocean.com/how-surimi-seafood-imitation-crab-is-made/