Page:Foods and their adulteration; origin, manufacture, and composition of food products; description of common adulterations, food standards, and national food laws and regulations (IA foodstheiradulte02wile).pdf/185

 Average Composition of Fish. —

Water,             76.06 percent Solids,            23.94   " Nitrogen,            3.51   " Phosphoric acid,     .52   " Sulfur,               .24   " Fat,                1.45   " Ash,                 1.21   " Protein,           21.92   "

Fluorids in Fish.—Nearly all kinds of fish yield a distinct test for fluorin which is not to be mistaken for an adulteration. The fluorin is found normally in the bones of the fish and sometimes in traces in the flesh. The addition of fluorid as a preservative is highly reprehensible, and its presence is indicated by the increase in quantity.

Marketing of Fish.—In the food act it is provided that no animals shall be used for food which have died otherwise than by slaughter. Whether or not this would apply to fish is a matter of some doubt. Unfortunately fish, as a rule, are allowed to die by being deprived of oxygen, which they get from the water as it passes over their gills. The common practice is to take the fish for commercial purposes in seines or other gear and allow them to die, as it were, by suffocation. The greater number of fish exposed upon our markets have died in this way and are then packed in ice and kept until sold. The ideal way to treat fish would be to transfer them from the seine to a pool of water, fresh or salt, in which they are kept alive until they are wanted for cooking. This method is practiced in some very high-grade restaurants and hotels where the diner may pick for himself from the pool the fish he desires to eat. It is evident that for commercial purposes where a cheap food is desirable a method of this kind could not be practiced. It is a question which the hygienist as well as the practical man should consider, that is, whether or not it is possible to slaughter the fish and, as soon as they are taken, dress them, pack their carcasses in ice, and in this way deliver them to the markets. Where fish are used for canning or salting purposes they are often slaughtered as soon as caught. This is particularly true of herring captured in the Potomac and Susquehanna rivers. It is an interesting problem to study whether or not the flavor and character of the flesh are impaired by the suffocation process subsequent to their capture. In all cases except in cold weather, the fish after capture, no matter whether they are allowed to die by suffocation or slaughtered, should be packed in ice and kept until the market is reached, which should be at as early a date as possible. Fish are never so good as when fresh and the fresher the better.

Cold Storage.—Fish is a product which is often found in cold storage in large numbers and kept there for a long time. The usual problem attending