Scientists extract protein from shrimp processing wastewater

According to foreign media reports, when shrimp are processed in a seafood processing plant, the resulting wastewater contains a lot of protein. Now scientists have devised a method to harvest this protein, and the collected protein can be used as animal feed or human food.

First of all, it should be noted that the organic matter has been removed from the wastewater before the shrimp processing wastewater is discharged into the water channel. This is usually achieved by adding chemical additives called flocculants, which allow the substances to come together.

These clumps will then float to the surface, where they can be skimmed and collected in the form of sludge. Unfortunately, the most commonly used flocculants are based on iron or other non-food grade compounds, so the harvested protein is not suitable for consumption. Instead, it is either converted into biogas or thrown directly into landfills.

Another method is to use a permeable membrane to filter organic matter in water. However, this method often blocks the equipment, which means that the parts need to be replaced, and the reality is that the replacement cost may be high.

In response, under the leadership of scientists Ingrid Undeland and Bita Forghani from Chalmers University of Technology in Sweden, the team turned to edible flocculants made from alginate extracted from seaweed and carrageenan. Through these technologies, researchers can extract up to 98% of protein from shrimp processing wastewater. When these extracts are dried and powdered, the protein and total lipids contained are as high as 61% and 23%, respectively-lipids include fatty acids and fat-soluble vitamins.

Scientists believe that this technology will easily expand its commercial use at low cost.

Related research reports have been published in "ACS Sustainable Chemistry & Engineering".