1995

New Processes for the Total Utilization of Fish


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There is no such thing as waste from processing raw materials harvested or grown in the oceans and fresh water bodies of the world. If all those in industry and science would discard the mindset of "waste," it would be realized that the dreaded materials are valuable "secondary raw materials." Total utilization of these materials can be of major economic importance while minimizing environmental effects and costs.

--George M. Pigott

George M. Pigott, director of the UW Institute for Food Science and Technology, today is witnessing the realization of a goal he set out decades ago to accomplish. "Thirty years ago, I began preaching about a better use of the 60 to 70% of harvested fish that is discarded, or reduced to cheap fish meal, after taking some of the edible flesh for conventional products such as steaks, fillets, and so forth," he recalls. Pigott and colleagues initiated projects under the category of what he called the "Total Utilization Concept," with the goal of complete utilization of fish and shellfish taken from the marine and freshwater bodies of the world.

Research over the years has culminated in the extensive use of processes developed at the UW for the production of a wide variety of high-quality formulated products. Examples include fish patties, fish sausages, and a variety of specialty products, among them, caviar from new species and refined fish oil. He and his students have also developed ways to reduce waste and environmental pollution from fish processing operations.

The research of Pigott and coworkers on surimi, a fish product used as a raw material to make imitation seafoods, led to methods to improve the stability of that material. The researchers discovered new ways to make surimi cheaper, to reduce its salt content, and to stabilize it against chemical changes that occur during frozen storage. Food processing and support companies including B. K. Laudenberg and Church & Dwight Corporation were involved in the research. Furthermore, Pigott and colleagues developed a way to recover proteins from the great volume of process waters that are generated in making surimi, thereby solving a critical waste problem. Technologies developed at the UW for surimi processing were transferred to a processing vessel called the Ocean Phoenix. UW graduates worked aboard that factory trawler and others to help implement the technology.

Methods used to improve the stability of surimi also have been applied to minced fish flesh. Pigott and colleagues have been working with the Prince William Sound Aquaculture Association in Alaska to develop new markets for pink salmon products produced using these new technologies.

In conjunction with the Port of Seattle, Pigott and his students have developed new processes for making fish fertilizer from the waste of local fish processing companies. The researchers use enzyme-based methods to extract peptides (protein fragments) of high nutritional value for humans, animals, and foliage fertilizers. Today, fish fertilizers based on technologies pioneered by Pigott are commonly available as commercial preparations. His technologies for making hydrolyzed protein products from fish muscle and fish by-products are being evaluated for use as animal feeds, protein additives, and food stabilizing agents.

Pigott's work over two decades ago with food-freezing systems has been widely implemented in the major food industries, recalls Barbara Rasco of the UW Institute for Food Science and Technology. "George was talking about freezing when everyone still thought that canning was the way to go," she notes. "He's always been ahead of his time. During the 1970s and 1980s he helped to develop the technology base that has led to the new fish sausages and hams now coming on the market. And he was among the first people to recover salmon roe from processing operations to sell as a high-quality food item on the Japanese market."

"As the world's fish resources are running low, we must find ways to maximize the productivity of fish processing operations, while avoiding waste and the ever-increasing costs of disposing of waste," emphasizes Rasco. The message Pigott was preaching those many years ago is finally an idea whose time has come.

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