The term surimi refers to concentrated myofibrillar protein extracted from fish flesh by washing minced meat that has been separated from bones, skin, and guts. After deboning of the fish, the sequence processes of making surimi involve mincing, washing and dewatering, refining, screw pressing, addition of cryoprotectant, and freezing (Park and Lin, 2005).
Some of the machines in surimi production:
• MEAT SEPARATOR. Fish meat separation achieved regardless to the species of fish (small fish to large fish).
• ROTARY SCREEN. Rotary Screen in the machine that removes contaminations remained in the bleached fish meat. It is equipped the shower device in it, and removes the contaminations through the screen with rotating while showering the water.
• REFINER. Using Refiner makes higher quality surmi.
• COOLING SILENT CUTTER. This cutter has the cooling water circulation Inside of the bowl to keep the fish meat temperature as low as possible. It is very important to keep the fish meat temperature lower for the quality of the Fish meat.
The washing technique used is an important key in determining the quality of the surimi. Minced fish flesh is rapidly washed with chilled water (5–10 oC), as low temperature water helps preserve the freshness of the raw material. This process removes undesirable matter such as blood, pigments, and other impurities, leaving the myofibrillar protein. The maximum amount of myofibrillar protein extracted is desirable because it influences the gel-forming ability of surimi. Next, the extracted myofibrillar protein is mixed with sugar or an alcohol sugar as a cryoprotectant. This mix is quick-frozen into frozen surimi blocks.
The principle factor that determines the quality of surimi is the freshness of the fish (Benjakul et al., 2002). Thus, handling of fresh fish is very important, and fresh fish and ice-stored fish are commonly used for surimi production. To prevent deterioration and denaturation of myofibrillar protein, proper post harvest handling is crucial. Freezing is often used to preserve fish during the time if it is required for travel between the catch site and the surimi manufacturing plant. Benjakul et al. (2004) studied the effect of frozen storage (–18 oC) on the gel-forming ability of four fish species (threadfin bream (Nemipterus spp.), purple-spotted bigeye (Priacanthus tayenus), lizardfish (Saurida spp.), and croaker (Pennahai macrophthalmus)) that are commonly used for surimi production in Thailand. They found that the difference in gel-forming ability depended on species and storage time. Threadfin bream was considered better against denaturation since it has lower formaldehyde content produced by extended frozen storage
SOURCE: (Picture and explanation is adapted from http://www.ube-yanagiya.com/html/products/surimi%20products/surimi-plant.html)