Moulded Surimi Products: Types and Preparation Methods

Walk through any supermarket’s frozen food aisle and you’ll find fish balls, fish nuggets, breaded cutlets, and ready-to-cook burgers sitting side by side. These aren’t just convenient frozen snacks – they are moulded surimi products, a category of seafood items that has grown into a major segment of global food processing. Built on a base of surimi (washed, refined fish protein paste), these products are shaped, seasoned, and cooked into forms that are familiar, versatile, and easy to prepare. Understanding how they are made – and what makes each type distinct – offers a clear window into modern seafood technology.

What are moulded surimi products? 🔗

Surimi, a Japanese term meaning “ground meat,” is a concentrated paste of myofibrillar fish proteins produced by mincing fish flesh, washing it repeatedly with cold water to remove fats and impurities, and then dewatering it into a smooth, cohesive base. Moulded surimi products are the family of seafood items created by blending this paste with binders, starches, and seasonings, then forming it into consumer-ready shapes such as balls, patties, cutlets, and nuggets.

According to IGNOU’s fishery science course material, moulded fish products occupy an important position among seafood products of commerce, with balls, burgers, cutlets, fingers, medallions, and nuggets all falling under this category. Their appeal lies in consistent texture, portion control, mild flavour, and ease of cooking – qualities that make them attractive to both household consumers and food service operators.

The base: role of surimi in moulded products 🔗

Surimi is not just a raw material – it is a functional ingredient. Its protein matrix, dominated by myosin and actin, has a unique ability to form elastic, heat-stable gels when combined with salt and cooked. This gel-forming capacity is what allows surimi to hold whatever shape it is moulded into, even after frying or steaming.

Food processing specialists note that starch – whether potato, tapioca, or corn – plays a critical supporting role. It acts as a stabiliser, contributing firmness, structure, and moisture retention to the final product. Without the correct starch-to-surimi ratio, a fish ball would fall apart in hot broth, and a nugget would turn rubbery after frying. ScienceDirect’s overview of surimi technology defines surimi as a concentrate of myofibrillar proteins obtained through mixing and water washing of fish flesh – it is this washed, protein-enriched base that gives moulded products their characteristic springy bite.

Common types of moulded surimi products 🔗

Fish balls 🔗

According to standard seafood processing protocols, fish balls are prepared by mixing minced fish or surimi with cornstarch, salt, and spices, forming the mixture into balls approximately 2-3 cm in diameter, and then cooking them in boiling brine for 8-10 minutes. The result is a firm, bouncy product with a clean flavour that readily absorbs surrounding broths.

Fish balls are among the most widely consumed surimi products globally. Wikipedia’s entry on surimi notes that in China, fish paste is routinely made into balls used in thick soups and hot pot meals, a tradition rooted in Fujian cuisine. They can also be further processed by pre-dusting, battering, and breading to create a coated fried variant, giving manufacturers flexibility in how the same base product reaches different markets.

Fish burgers and patties 🔗

Fish burgers are essentially round, flat patties made from cooked surimi or lean white fish mince combined with cooked potato and mild spices. Industry preparation guidelines describe a process where the cooked mince mixture is formed into round shapes, then battered, breaded, and flash-fried for approximately 20 seconds to set the coating before final cooking by the consumer.

A key advantage of fish burgers is their nutritional profile relative to meat-based alternatives. Research published in Food Science & Nutrition found that surimi-based products showed lower lipid oxidation indicators during frozen storage compared to unwashed fish mince products – meaning surimi burgers tend to stay fresher and more stable over time. The washing process removes a significant portion of fat and blood pigments, which directly reduces oxidative deterioration during storage.

Fish cutlets 🔗

Fish cutlets take a slightly different formulation approach. Processing guidelines specify that cutlets are prepared using cooked fish mince mixed with cooked potato, fried onion, and spices, then formed into individual pieces weighing approximately 40 grams each. The shaped cutlets are battered, breaded, and flash-fried before packaging.

The higher proportion of potato and vegetables in cutlets compared to burgers makes them more filling and economical to produce. The potato also functions as a natural binder, helping the mixture hold oval or rectangular shapes during moulding. Careful attention to the moisture balance in the mixture is essential – too much water and the cutlet disintegrates; too little and it becomes dense and dry after cooking.

Fish nuggets 🔗

Fish nuggets are bite-sized, portion-controlled pieces designed for quick cooking and easy eating. They are typically made from surimi or minced fish combined with binders and seasonings, formed into small chunks, coated with batter and breadcrumbs, and fried. A peer-reviewed study in Food Science & Nutrition (2019) comparing surimi nuggets with conventional fish nuggets found that the surimi-based versions scored higher on all sensory attributes – including colour, texture, and overall acceptability – at the end of the frozen storage period. The researchers attributed this to the washing process of surimi production, which improves gel strength, colour, and microbial stability.

Fish fingers and medallions 🔗

Beyond the main four, the moulded category also includes fish fingers and medallions. Fish fingers are produced by freezing mince into rectangular slabs, sawing the slabs into thin finger-shaped pieces, battering, breading, and flash-frying them. Medallions follow a similar principle but are formed into round, coin-like shapes. Both are popular in institutional catering and children’s food segments because of their predictable size and ease of preparation.

Key ingredients in moulded surimi products 🔗

The formulation of any moulded surimi product involves several functional ingredients beyond the surimi base itself:

Starches (potato, corn, tapioca): Provide binding, structure, and moisture retention. Food technologists emphasise that starch choice affects both texture and stability during cooking – potato starch, for example, creates a softer bite compared to tapioca, which gives a chewier result.

Salt: Essential for solubilising myofibrillar proteins to activate gel formation. Without salt, the proteins cannot form the elastic network that gives these products their characteristic bounce.

Spices and seasonings: Onion, garlic, pepper, and other flavourings customise the product for regional tastes. Research also suggests that certain spices such as garlic have natural antimicrobial properties, contributing to the microbial stability of moulded products during frozen storage.

Phosphates and stabilisers: Phosphates are used to dissociate actomyosin into actin and myosin components, which increases water retention in the product. Studies confirm that phosphate additives play a prominent role in maintaining moisture balance in surimi seafood products.

Egg white or transglutaminase: Used as additional binders to improve gel strength, particularly with fish species that have weaker natural gel-forming ability.

General preparation process 🔗

While specific steps vary by product type, the general preparation sequence for moulded surimi products follows a consistent logic:

1. Mixing: Surimi is combined with salt first to solubilise proteins, followed by starch, spices, and other additives. The mixture is processed in a silent cutter or bowl chopper to achieve a homogenous paste.

2. Moulding: The paste is shaped using hand-rolling (traditional, for fish balls), automatic moulding machines, or extrusion equipment depending on the product form and production scale.

3. Setting: The shaped product goes through a low-temperature setting phase (typically 40°C for 30-60 minutes) before final cooking. This step, known as suwari in Japanese processing terminology, allows the protein network to partially gel, which improves the final product’s texture and elasticity.

4. Cooking: Final cooking is carried out by steaming, boiling, frying, broiling, or baking depending on the product. According to established processing practice, steaming is the gentlest method – it preserves flavour and yields a moist, tender texture ideal for products destined for soups and broths. Frying creates a crisp exterior with a softer centre, preferred for nuggets and cutlets. Broiling firms the surface while keeping the interior tender, making it suitable for burger patties.

5. Coating (where applicable): Products like nuggets, cutlets, and fingers receive a pre-dust, batter, and breadcrumb coating before flash-frying to approximately 20 seconds. This sets the exterior coating without fully cooking the interior, leaving final cooking to the consumer.

6. Freezing and packaging: Products are blast-frozen and vacuum-packed or sealed in trays for retail or institutional distribution. Industry data indicates that frozen surimi-based products can maintain quality for up to 18 months when stored correctly.

Nutritional value and market relevance 🔗

Moulded surimi products offer a nutritionally meaningful seafood option in a convenient format. Research on milkfish surimi-based products found that crude protein was the dominant solid component in fish balls and nuggets, with fat content remaining well within the limits recommended by the WHO for healthy dietary fat intake. The proximate composition varied somewhat across product types depending on added ingredients and seasonings – but all products retained a protein-dominant nutritional profile.

Global production data points to the scale of this industry: two to three million tonnes of fish annually – roughly 2-3% of world fisheries supply – go into surimi and surimi-based product manufacturing. The United States, Japan, Thailand, and China are the leading producers, with newer players including Vietnam, Malaysia, Chile, and several European nations expanding their share.

From street food in Southeast Asia to school canteens in Europe, moulded surimi products have established themselves as one of the most adaptable and widely consumed forms of processed seafood. Their success comes down to a precise combination of functional food science – protein gelation, starch binding, moisture control – and practical consumer appeal: consistent shape, easy cooking, and reliable flavour.

What do you think? Given that surimi products can be made from low-value fish species that might otherwise go to waste, do you think they represent an underutilised opportunity for sustainable seafood processing in developing fishing nations? And as a consumer, does knowing the science behind the texture and shelf stability of products like fish balls and nuggets change how you think about the seafood in your freezer?

References

1. https://en.wikipedia.org/wiki/Surimi
2. https://egyankosh.ac.in/bitstream/123456789/9839/1/Unit-5.pdf
3. https://meatcheftools.com/how-do-they-make-surimi/
4. https://www.sciencedirect.com/topics/food-science/surimi
5. https://www.slideshare.net/slideshow/surimi-based-products-fishery-products-b/244359004
6. https://pmc.ncbi.nlm.nih.gov/articles/PMC6804757/
7. https://onlinelibrary.wiley.com/doi/abs/10.1002/fsn3.1172
8. http://www.qlfoods.com/surimi.php
9. https://innspub.net/wp-content/uploads/2024/04/JBES-V24-No3-p37-42.pdf