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/81

 The two samples given are extreme cases in the method of preparing meats for canning. In the first instance the meat is placed at once into hot water just below the boiling point and kept there for only a short time. In the second case the meat is placed in cold water and is brought to the boiling point and maintained there for one hour. In the last case the low temperature of the water in which the meat was originally placed favors the extraction of a portion of the soluble protein matter, namely, albumins, globulins, etc., while, on the other hand, the long-continued boiling to which it was subjected tends to decompose the connective tissues of the meat and causes the loss of small particles of the insoluble protein thus separated by disintegration. Although in the last case the shrinkage was much greater than in the preceding experiment, practically no insoluble protein matter was extracted, mechanically or otherwise.

Canning of Beef without Parboiling.—To determine the amount of shrinkage which takes place and the general effect which is produced by canning meats without parboiling, samples were prepared, sterilized, and canned in the usual way, with the exception of the omission of parboiling. On opening the cans it was found in each case that the meat had shrunk to about two-thirds of its former volume and that the place was occupied by a liquid containing a number of particles of solid matter. The appearance of the sample was much less inviting than that of meat canned after parboiling.

An analysis of the sample was made, with the following results: Total weight of sample, 31 ounces; weight of canned meat, 21 ounces.

Water,                                    63.83 percent Protein,                                  27.25    " Meat bases,                                 1.09    " Fat,                                       4.62    " Ash,                                        1.01    " Salt,                                       .04    " Undetermined,                               1.20    "

Composition of Liquid.—The liquid in the can was examined with the following result: Weight of liquor, 10 ounces.

Solids,                                    6.93 percent Protein and gelatin,                       1.94    " Meat bases,                                 1.84    " Ash,                                       1.22    " Salt,                                       1.15    "

The above data show that the beef lost 32.06 percent of its weight in the canning, a little over half of which is water.

It appears that less protein matter is extracted when the meat is parboiled by being plunged into boiling water than when it is packed in a can without parboiling and subsequently subjected to the temperature of sterilization. In the former case the soluble proteins in meat near the surface are coagulated before they can diffuse into the surrounding water. In the other case, owing to the