Advanced US method to boost fish yields

A process called pH shifting may significantly increase yield from usual methods that lose 30-40% of the soluble protein during the washing of whitefish, says 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.

''Conventional yield maxes out at about 60% even when soluble proteins are recaptured. Meanwhile, pH shifting can yield 85-90%,'' 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.