Study: Surimi wash-water could recover fish protein

Recycling protein from surimi wash-water that is usually ditched could serve as an additional source of fish protein ingredients for the food industry, new research suggests.

According to researchers at the US Department of Agriculture’s (USDA) Subarctic Agricultural Research Unit, the protein could be recovered during surimi processing and then be added back to boost the final surimi yield. During the surimi manufacturing process, minced fish flesh is repeatedly washed with chilled water to eliminate non-essential proteins, lipids and other water soluble materials, leaving an odourless and tasteless product that typically contains between 0.5-2.3% pure protein.

For the study, which was published in the Journal of Food Quality, the research team led by Professor Jesse Stine evaluated methods to recover lost fish protein from surimi wash-water that is usually discarded during processing. The researchers studied the potential of membrane filtration technology in recovering the washed out protein and the other properties of solids from waste water.

The outcome revealed that the fish protein recovered during the trial was nutritionally similar to the final surimi product, and had significantly higher moisture and lipid content and a higher number of lower molar mass proteins, compared to the regular surimi. The researchers suggested that the recovered protein can be added back at a low percentage to surimi products to increase the overall yield, or to develop a fish ingredient.

The new method to recover fish proteins from water could lower environmental impact, reduce the cost of waste disposal, and help manufacturers find new ways to generate profit, the researchers added.

Caption: The recovered protein from surimi wash-water can be added back at a low percentage to increase the overall surimi yield, or to develop a fish ingredient. Image courtesy of Natto.