Analyzing the Safety of Seafood Following the Gulf Oil Spill
Due to the size and persistence of the oil spill in the Gulf of Mexico following the Deepwater Horizon explosion, the methods for testing the safety of the affected seafood were inadequate and new protocols had to be designed on-the-fly, according to presenters at a Saturday morning IFT Pre-Annual Meeting Short Course on Evaluating the Safety of Gulf Seafood: Programs and Analytical Techniques in the Aftermath of the Deepwater Horizon Spill.
Steven Wilson, Chief Quality Officer of the Seafood Inspection Program for the U.S. Dept. of Commerce, discussed Management Decisions for Sensory Analysis in an Emergency Environment. Scientists want to collect data, analyze it, and collect more data to get a total picture, said Wilson. In contrast, food safety professionals have to make “yes” or “no” decisions with some level of risk. The latter mindset was critical in establishing protocol for reopening areas for fishing and seafood harvesting following the gulf oil spill.
Sensory analysis became the standard test for reopening various areas; chemical analyses were also employed. At one point, nearly 40% of the Gulf of Mexico was closed to fishing, noted Wilson. Initially, the sampling program targeted 30 specifies of fish and shellfish. But it was quickly determined that the volume of samples would overwhelm the testing laboratory and sensory panelists. Instead, the sampling program focused on top, middle, and bottom feeders through the use of nets and line trawling. Protocols were developed for sample size, storage, and chain of custody.
The existing protocol called for wrapping a sample of the fish in aluminum foil on the fishing vessel and sending it to the laboratory in Pascagoula, Miss. But due to the hot temperatures in the region, many samples were showing up in the lab in a highly decomposed state. New protocols were put in place, treating the fish as if it were a commercial catch. Wilson told an amusing story of how one fishing vessel called to ask about how it should wrap a 300-lb bluefin tuna in foil.
Another challenge was training the sensory panelists. Due to the burning of the oil and the resulting odor and potential contamination in the area, it was decided that training should take place at a laboratory in Gloucester, Mass. The actual sensory testing was done at the laboratory in Pascagoula. Panelists analyzed for raw odor, cooked odor, and cooked flavor.
Samples were spiked with oil and dispersants as a QC check. This was done sparingly due to the limited availability of the seafood supply in the gulf. Even so, the testers went through about 6 million lbs of purchased seafood in two months.
It’s quite common in sensory analysis to blend samples. But this protocol was quickly abandoned with oysters as the product produced a near-gag reflex, explained Wilson.