New surimi method could increase fish yields

PH shifting retains all of the fish proteins except for the connective tissue -- an improvement over conventional processing. (Photo: Ncsu.edu/ FIS)

A process called pH shifting may dramatically boost yield from usual methods that lose 30-40 per cent of the soluble protein during the washing of whitefish, contends a food science expert.

Surimi is made from grinding and washing muscle tissue usually acquired from fish by-products and into items such as imitation crab legs and fish sticks. It is Alaska’s top export from its pollock fishery to Japan.

North Carolina State food science professor Tyre Lanier says that pH shifting retains all of the protein except for the connective tissue -- as opposed to conventional washing processes, which leave behind the main muscle and connective tissue, the Alaska Journal of Commerce reported.

Conventional yield maxes out at about 60 per cent even when soluble proteins are recaptured. Meanwhile, pH shifting can yield 85-90 per cent, according to Lanier.

The process of pH shifting also provides better gelation, or the solidification of the finished product, without requiring the use of additives.

Lanier presented at the second International Congress on Seafood Technology in Anchorage last month and said that converting the surimi industry to pH shifting represents a paramount challenge.

"In every industry, it doesn't matter what it is, people get used to way things are," Lanier explained.

Using existing species would be a huge change for the industry, but "when we come out with a new species, if you made it by a totally new process, who's to know the difference? You get used to new process," Lanier continued.

Squid was chosen to test the scalability of the method for its white flesh, which makes it appear similar to traditional high-grade surimi. It cannot be made into surimi through conventional methods and it is available copiously from Peru — which is where the first surimi plant using pH shifting will run — to southern California.

If successful, the pH shifting technology could be marketed to companies establishing new surimi processing plants and especially in Asia, where the Chinese industry has rapidly expanded and lowered equipment costs, Lanier said.

New species beyond squid such as catfish or carp could also be targeted for surimi production, especially if industry moves toward aquaculture as a means to cultivate fish for surimi.

Sumber : FIS Indonesia