Chinese-style Salted Fish

In southern China, about 20 different fish, such as red snapper, threadfin, Spanish mackerel, croaker, Japanese mackerel, are used to prepare salted fish (Armstrong & Eng, 1983; Poirier et al., 1987). Procedures for preparation of salted fish have been described in detail previously (IARC, 1993). Briefly, salted fish are prepared by salting, brining, dry-salting, pickle curing, or a combination of these treatments. In brining, fish are placed in a solution of crude salt in water until the fish tissue has absorbed the required amount of salt. For dry-salting, fish are mixed with dry salt and the resultant brine (from dissolution of the salt in the water present in the fish) is allowed to drain away. When pickling or pickle curing the fish is mixed with salt and stored under the brine (pickle) formed when the salt dissolves in the water extracted from the fish. In southern China, fish are generally not gutted before salting, and only when bigger fish such as red snapper are salted are the guts drawn out through the throat, without making an incision in the belly of the fish. Salting is done with crude salt in wooden vats. After a few days, the fish are immersed in brine and weights (often large stones placed on top of grass mats) are placed on the surface to prevent the fish from floating, for one to five days. After this the fish are dried under the sun for one to seven days, depending on the size of the fish and the weather. Salted fish prepared in this way are called ‘tough’ or ‘hard meat’ salted fish. Sometimes, fish is allowed to soften by decomposition before salting, to produce ‘soft meat’ salted fish (Poirier et al., 1989; Yu et al., 1989a). During drying salted fish, insect infestation can be a serious problem, especially in damp weather. In southern China, the average annual temperature and humidity are high and are favourable for the growth of bacteria such as Staphylococci (Armstrong & Eng, 1983; Zou et al., 1994). Salted fish are stored for 4 to 5 months before being consumed.