POTENTIAL FOR ISOELECTRIC SOLUBILIZATION/PRECIPITATION TO IMPROVE NUTRITIONAL VALUE OF GREEN CRAB (Carcinus maenus) MEAL FOR AQUAFEEDS

The European green crab (Carcinus maenus) is a highly successful invasive predator with well-established populations along the east and west coasts of North America. This species has significant negative impacts on estuarine habitats, molluscan aquaculture, and commercially important fisheries. Although green crabs represent a good source of high quality protein, their extremely small carapace width limits their use in the North American seafood market. Previous researchers reported that whole green crab meal showed promise as an alternative protein ingredient in fish feeds given its excellent amino acid profile. However, an ash content of over 50% (dwb) limits its use to ash tolerant species.  More recent research evaluated the nutritional profile of meal produced from mechanically separated (deshelled) green crab mince and recommended that further research focus on optimizing shell extraction from soft tissue and on reducing ash content.  One approach is to use the isoelectric precipitation/solubilization (ISP) process, which solubilizes proteins at high or low pH and then recovers them at their isoelectric point.  This process has been successfully applied to a variety of plant and animal proteins, including soy and low-value finfish by-products.  The objective of the current study was to evaluate the potential of the ISP method to reduce the ash content and improve the nutritional value of green crab meal for aquafeeds.