Removal of lipids and diarrhetic shellfish poisoning toxins (DSP) from blue mussels (Mytilus edulis) by an acid or alkaline protein solubilization technique

Journal article, 2008

Diarrhetic shellfish poisoning (IDSP) toxins pose a serious health risk for consumers of bivalves and other shellfish, as well as a huge economic burden for the bivalve-producing farmers. In this work, the aim was to utilize a solubilization-based protein-isolation method to produce a low-DSP toxin protein isolate from toxic blue mussels that are unsuitable for the whole shellfish market. A homogenate of whole mussel meat was solubilized at low pH (2.8) or high pH (11.1), followed by centrifugation and reprecipitation of the solubilized mussel proteins at the isoelectric pH. In a second centrifugation, precipitated proteins were collected. These processes resulted in 81 (acid solubilization) and 72% (alkaline solubilization) reduction in the initial DTX-1 toxin content of the mussel meat. No other DSP toxins were-found in the protein isolates. Acid processing of mussel meat resulted in 50% reduction in the total lipid content, while alkaline treatment did not significantly affect the) lipid content. The effect of citric acid and calcium chloride addition to the mussel meat-water homegenate on lipid and toxin content was also investigated. A poor correlation factor was surprisingly obtained between reductions in DTX-1 toxin and lipids in protein isolates from,processed toxic mussels. Results from an analytical mass balance of the DTX-1 toxin during acid processing showed that 61% of this toxin ended up in the aqueous supernatant after the second centrifugation. The present study presents a promising alternative way of utilizing mussels for food production in periods when they are toxic.