title: Removal of lipids and diarrhetic shellfish poisoning toxins from blue mussels (Mytilus edulis) during acid and alkaline isolation of proteins.
abstract: Diarrhetic shellfish poisoning (DSP) 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 homogenate 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.
authors.affiliation: Department of Chemical and Biological Engineering, Food Science, Chalmers University of Technology, SE 402 29, Gothenburg, Sweden. patroklo@chalmers.se
authors.forename: Patroklos
authors.initials: P
authors.lastname: Vareltzis
authors.forename: Ingrid
authors.initials: I
authors.lastname: Undeland
mesh_terms: D000818:Animals; D002122:Calcium Chloride / Q000008:administration & dosage; D019343:Citric Acid / Q000008:administration & dosage; D004141:Dinoflagellida / Q000378:metabolism; D005511:Food Handling / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000302:isolation & purification*; D008387:Marine Toxins / Q000032:analysis / Q000302:isolation & purification*; D049880:Mytilus edulis / Q000737:chemistry*; D019319:Okadaic Acid / Q000031:analogs & derivatives; D011506:Proteins / Q000302:isolation & purification*; D011714:Pyrans / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D008055:Lipids; D008387:Marine Toxins; D011506:Proteins; D011714:Pyrans; D019319:Okadaic Acid; D019343:Citric Acid; C051904:dinophysistoxin 1; D002122:Calcium Chloride