The Species of Hakes
There are several species of hakes, the most important of which is the silver hakes or whiting.
The whiting is most abundant in waters off Nova Scotia. It is caught and handled in much the same manner as are cod. Some whiting are headed, guttered, washed and frozen without further cutting, for utilization as food.
With all members of the cod family, small fish, species not especially prized as food (red hake, etc) and fish frames (the portion remaining after the fillet has been cut away) may be passed through mechanical meat/bone separators (machines that separate the flesh portion from bones and skin).
This provide significant yield of edible, ground fish flesh (resembling hamburger in texture) that may be used to produce frozen fish blocks to be further processed into fish portions, fish sticks and so on.
Handled in conventional fashions, such products are not stable in frozen storage since the fat oxidize and becomes rancid, and the issues get tough at a faster rate than that of the corresponding fillets held under the same conditions.
The faster oxidation of fats probably due to a greater exposure to oxygen because of the great increase in surface area.
The increased rate of toughening may be due to a wider distribution of the enzyme that decomposes trimethylamine to form dimethyl amine and formaldehyde.
The latter composes known to denature proteins.
The spoilage reactions may be slowed considerably by storing at lower temperature, e.g. -20 degree F or -28.9 degree C.
Rancidity can be prevented altogether by protecting the product with a wrapper or gas impermeable plastic film, for example, polyester, PVC, Nylon 11, aluminum laminate.
The Species of Hakes
