Surimi wash water

Huang, L. and Morissey, M. (1998) Fouling of membranes during microfiltration of surimi wash water Roles of pore blocking and surface cake formation. Journal of Membrane Science, 144, 113-123. 

Wibowo, S., Velazquez, G., Savant, V., Torres, J.A., 2005. Surimi wash water treatment for protein recovery efect of chitosanalginate complex concentration and treatment time on protein adsorption. Biotesource Technology 96 (6), 665—671. 

One potential application of chitosan complexes in seafood processing is the treatment of surimi wash water (SWW), which contains 0.1%-2.3% protein (Morrissey et al. 2000) to obtain not only clean wash water for reuse in the plant but also to recover suspended proteins for use in feed production. Flocculation of SWW protein by using Chi-Alg at a concentration of 100 mg complex/L SWW for 1 h achieved high protein adsorption and turbidity reduction (Wibowo et al. 2005a,b). The Chi-Alg complex is an effective alternative in not only recovering soluble proteins that would otherwise be discarded into the environment, but more so an economically viable downstream process over expensive, commercial membrane treatments and their limited use due to periodic fouling (Savant 2001). Insoluble proteins can be recovered in the same step used for SWW (Wibowo et al. 2007). 

Wibowo, S., Savant, V., Cherian, G., Savage, T.F, and Torres, J.A. 2005a. Evaluation as a feed ingredient of surimi wash water protein recovered using a chitosan-alginate complex. J. Aquat Food Prod. Technol. 14(1) 55-72. 

A method for the removal of parvalbumin due to its high water solubility is thorough washing of the fish meat. Such products (particularly surimi) present an allergen pattern different from the native fish species with reduced allergenicity due to no detectable parvalbumin but other allergens (Mata et al. 1994). 

Surimi is the Japanese term for an intermediate food product prepared by washing mechanically deboned fish mince (Okada, 1985). The process removes water-soluble proteins, enzymes, blood and metal ions. The removal of these nutrients for microbial growth leads to its greater stability (Green and Lanier, 1985). A representation of the process is shown in Figure 2.1. Surimi is an off-white, odourless material with a bland flavour. The proteins myosin and actin are the major components and these salt-soluble fish proteins have the ability to form a strong, highly elastic gel at relatively low temperatures c, 40°C) (Niwa, 1985). After preparation it is mixed with cryoprotectants and then frozen. 

In the traditional process for fish surimi production, the fish flesh is washed on large screens and the oil is washed through the screens. This process is suitable for the separation of the liquid oil from fish however, solid fats (such as occur in red meat) would not separate in this way but would remain on the screens with the water-insoluble proteins. Red meat also contains higher levels of fat than white fish. Fat separation from meat is therefore more difficult than from fish. Separation can be carried out using flotation and skimming however, this introduces further steps into the process and increases processing times. 

Workers in New Zealand have developed a process for the preparation of surimi from mutton (Torley et al., 1988). The chief problem they encountered was that sheep meat contained a high level of collagen (21%), compared with that of fish flesh (3%). To counter this problem extensive comminution of the mutton, to break down the collagen, was carried out prior to water-washing. 

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