The following analyses of smoked and salted meats and fish are from the works of Strohmer and Konig: Action on Serafini and Ungaro found that smoke acts energetically on pure cultures of bacteria, those of anthrax being killed in two and one-half hours, and spores in 18 hours. Bacilli in the incerkr the meat were not killed. Forster foec bacilli of tuberculosis still virulent in the nor of meat after it had been salted smoked.
During the process of salting and gss.k. the coloring matter of meat is changed shown by the spectroscope. Smoked ban r.. other meats have an alkaline reaction.
5. Preservation by Exclusion of Air Are Sterilization by Heat.— In early times -., was preserved to a limited extent by beai. earthen vessels, and sealing hermetima such crude processes as were available_ A: present day such methods have given play preservation, either in tin cans or boxes c glass. In the former instance food may be r served for long periods by means of soldr: and in the latter by means of tight-fitting 3=f_ and rubber rings. The latter method is at much used in trade but is largely employee 1 household purposes. In the canning operz,-.. of the home, about one-fourth of a were i sugar is added to the pound of fruit sic 1 has been sufficiently cooked. The hot free its juice is then poured into the glass jar1 to within one-quarter of an inch from the drip is carefully wiped away with a •1 cloth and the rubber band is adjusted 0:ei a time the jars are filled full with briskly hii: water from a tea-kettle and the convex Y. cover pressed down immediately into the s-2' ing liquid and the jar clamped. The use c: 1 boiling water not only conduces to dears. about the rubber ring, but, by its steam c:c the last particle of air which might oxygen for fermentation. The later and ''.ci method employed in home canning is en first thoroughly sterilizing jars, tops and ri rings; then filling with the fresh fr= syrup, prepared from sugar and boiling — the amount of sugar varying accorchr the variety of fruit; cover jars, but de seal, and place in boiler of water. When is cooked, remove jars, fill if need , boiling water and seal. This process p fruit, as well as vegetables, which are canned in this way, from cooking to and does not tend to change the os color.
In the United States the preservatiel meats, poultry, fish, vegetables and fruits manner has become an important inellectrr-1 branch of commerce, both domestic and national. The canning of meats is cove to a great extent in those cities where slaughtering establishments are located canning of vegetables and fruits is carried.r places located in the great gions, while the fish canneries are mostly:" the rivers and in the seacoast towns el: Northeast and Northwest States and where the fish are taken from the water. cans filled with their contents are either ha; in steam retorts or partially immersed in ing water. A small hole is left in the and while still hot the hole is dosed with of solder. In a few days the cans are r by tapping them with a wooden mallet or mer. If the cap sinks, slowly the can has properly sealed, but if it is elastic, and .. 1 back, it is rejected as a I-. preservation of corned beef, the cans pierced to allow the water and fat to escape, and are then soldered and placed in boiling water again for several hours.
Canned-roast-beef is largely used as a part of the army and navy ration, especially during the time of war, and upon the frontier. The method of preparation is thus described by Munson: ((The beef is first placed in water and maintained at a temperature of 204° F. until well cooked. It is then removed, trimmed and placed in cans, a little gelatine being added to bind the meat together. The cans are then sealed and either submerged in boiling brine or placed in superheated steam at 257° F. The steam in the can escapes through a puncture made in the top of the can which is immediately afterward closed with solder. The meat being sealed while hot, any unfilled portion of en closed space becomes a partial vacuum when the cooling of the can condenses the steam; consequently a good can of meat will usually present a concave appearance on the outside, from atmospheric pressure.
When a can is bulged it is bad — unless frozen—and should be rejected. Freezing causes a bulging of the ends of the cans with out injury to their contents. The ends, after the contents are thawed, return to their former shape, unless this mishap has been several times repeated.